Polydentate N,O-Ligands Possessing Unsymmetrical Urea Fragments Attached to a p-Cresol Scaffold
Abstract
:1. Introduction
2. Results and Discussion
3. Materials and Methods
3.1. General
3.2. General Procedure for the Preparation of Bis-Amines 1
- 2,6-bis((benzylimino)methyl)-4-methylphenol: 99% yield; orange solid; m. p. 69.6–69.7 °C (lit. 68–72°C [46]).
- 2,6-bis((phenylethylimino)methyl)-4-methylphenol: 68% yield; orange oil; 1H NMR 2.28 (s, 3H, CH3), 3.01 (t, 4H, J 7.4, CH2-Ph), 3.85 (t, 4H, J 7.4, CH2-N), 7.19–7.24 (m, 6H, CH-2+6 and CH-4 Ph), 7.29 (t, 4H, J 7.5, CH-3+5 Ph), 7.45 (bs, 2H, CH-3 and CH-5), 8.438 (bs, 2H, CH=N), 13.92 (bs, 1H, OH).
- 1a: 99% yield; reddish oil; 1H NMR 2.32 (s, 3H, CH3), 4.39 (s, 4H, CH2), 6.82 (dd, 4H, J 7.6, 1.1, CH-2+H-6 Ph), 6.88 (tt, 2H, J 7.3, 1.1, CH-4 Ph), 7.03 (s, 2H, CH-3 and CH-5), 7.27 (td, 4H, J 7.4, 1.1, CH-3+5 Ph); 13C NMR 20.6 (CH3), 46.4 (CH2), 114.7 (CH-2+6 Ph), 119.3 (CH-4 Ph), 124.4 (Cq-2 and Cq-6), 128.8 (CH-3 and CH-5), 128.9 (Cq-4), 129.3 (CH-3+5 Ph), 147.9 (Cq-1 Ph), 152.8 (Cq-1).
- 1b: 98% yield; yellowish oil; NMR identical with the literature data [47].
- 1c: 88% yield; colourless oil; 1H NMR 2.20 (s, 3H, CH3), 2.86 (t, 4H, J 6.9, CH2-Ph), 2.92 (td, 4H, J 6.9, 1.3, CH2-N), 3.87 (s, 4H, CH2-bridge), 4.89 (bs, 2H, NH), 6.80 (s, 2H, CH-3 and CH-5), 7.19-7.22 (m, 6H, CH-2+6 and CH-4 Ph), 7.29 (td, 4H, J 7.4, 1.7, CH-3+5 Ph); 13C NMR 20.40 (CH3), 35.8 (CH2-Ph), 49.9 (CH2-N), 50.6 (CH2-bridge), 123.5 (Cq-2 and Cq-6), 126.3 (CH-4 Ph), 127.7 (Cq-4), 128.6 (CH-2+6 Ph), 128.7 (CH-3+5 Ph), 128.8 (CH-3 and CH-5), 139.4 (Cq-1 Ph), 154.1 (Cq-1).
3.3. General Procedure for the Preparation of Ligands 2 and 3
- Ligand 2aa: Rf 0.65 (0.5% MeOH/DCM); colourless solid; m. p. 111.6–112.8 °C; 1H NMR 2.09 (s, 3H, CH3), 4.36 (s, 2H, CH2-Cq-6), 4.77 (s, 2H, CH2-Cq-2), 6.13 (s, 1H, NH-CO), 6.37 (d, 1H, J 2.0, CH-3), 6.70 (tt, 1H, J 7.3, 0.9, CH-4 Ph-N(6) of R1), 6.72 (dd, 2H, J 8.6, 0.9, CH-2+6 Ph-N(6) of R1), 7.03 (m, 1H, CH-4 Ph of R2), 7.04 (d, 1H, J 2.1, CH-5), 7.16 (ddt, 2H, J 8.5, 7.3, 1.9, CH-3+5 Ph-N(6) of R1), 7.19 (dd, 2H, J 8.5, 1.5, CH-2+6 Ph-N(2) of R1), 7.25 (m, 4H, CH-2+6 and CH-3+5 Ph of R2), 7.46 (tt, 1H, J 7.1, 1.3, CH-4 Ph-N(2) of R1), 7.48 (ddt, 2H, J 8.6, 7.0, 1.3, CH-3+5 Ph-N(2) of R1), 9.94 (bs, 1H, OH); 13C NMR 20.36 (CH3), 44.5 (CH2-Cq-6), 50.5 (CH2-Cq-2), 113.6 (CH-2+6 Ph-N(6) of R1), 117.6 (CH-4 Ph-N(6) of R1), 119.8 (CH-2+6 Ph of R2), 122.6 (Cq-2), 123.7 (CH-4 Ph of R2), 126.8 (Cq-6), 127.9 (Cq-4), 128.9 (CH-3+5 Ph of R2), 129.0 (CH-4 Ph-N(2) of R1), 129.1 (CH-2+6 Ph-N(2) of R1), 129.2 (CH-3+5 Ph-N(6) of R1), 130.1 (CH-5), 130.5 (CH-3+5 Ph-N(2) of R1), 130.9 (CH-3), 137.8 (Cq-1 Ph of R2), 140.2 (Cq-1 Ph-N(2) of R1), 148.3 (Cq-1 Ph-N(6) of R1), 152.0 (Cq-1), 156.1 (C=O); ESI MS m/z 226 [M-NPhCONHPh]+ (100), 371 [M − Cl]+ (36), 407 [M+1]+ (58), 429 [M + Na]+ (18).
- Ligand 3aa: Rf 0.35 (0.5% MeOH/DCM); pale brown solid; m. p. 91.1–91.3 °C; 1H NMR 2.07 (s, 3H, CH3), 4.88 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 6.59 (s, 2H, NH-CO), 6.677 (s, 2H, CH-3 and CH-5), 7.00 (tt, 2H, J 7.4, 1.0, CH-4 Ph of R2), 7.22 (m, 8H, CH-2+6 Ph of R1 and CH-3+5 Ph of R2), 7.31 (dd, 4H, J 8.6, 1.0, CH-2+6 Ph of R2), 7.33 (tt, 2H, J 7.4, 1.1, CH-4 Ph of R1), 7.42 (t, 4H, J 7.6, CH-3+5 Ph of R1), 10.06 (bs, 1H, OH); 13C NMR ; 20.4 (CH3), 49.4 (CH2-Cq-2 and CH2-Cq-6), 119.6 (CH-2+6 Ph of R2), 123.2 (CH-4 Ph of R2), 124.0 (Cq-2 and Cq-6), 128.16 (Cq-4), 128.24 (CH-4 Ph of R1), 128.6 (CH-2+6 Ph of R1), 128.8 (CH-3+5 Ph of R2), 130.1 (CH-3+5 Ph of R1), 131.0 (CH-3 and CH-5), 138.5 (Cq-1 Ph of R2), 141.1 (Cq-1 Ph of R1), 151.2 (Cq-1), 155.5 (C=O); ESI MS m/z 557 [M + 1]+ (16), 579 [M + Na]+ (54), 595 [M + K]+ (7), 1135 [2M + Na]+ (100).
- Ligand 2ab: Rf 0.70 (1% MeOH/DCM); colourless solid; m. p. 137.2–137.3 °C; 1H NMR 2.09 (s, 3H, CH3), 4.37 (s, 2H, CH2-Cq-6), 4.40 (d, 2H, J 5.8, CH2 of R2), 4.58 (t, 1H, J 5.8, NH-CO), 4.72 (s, 2H, CH2-Cq-2), 6.34 (d, 1H, J 2.0, CH-3), 6.69 (tt, 1H, J 7.3, 1.0, CH-4 Ph-N(6) of R1), 6.72 (dd, 2H, J 8.4, 0.7, CH-2+6 Ph-N(6) of R1), 7.04 (d, 1H, J 1.8, CH-5), 7.11 (dd, 2H, J 8.6, 1.4, CH-2+6 Ph-N(2) of R1), 7.17 (m, 4H, CH-3+5 Ph-N(6) of R1 and CH-2+6 Ph of R2), 7.23 (tt, 1H, J 7.4, 1.9, CH-4 Ph of R2), 7.29 (td, 2H, J 7.6, 1.6, CH-3+5 Ph of R2), 7.36 (tt, 1H, J 7.3, 1.2, CH-4 Ph-N(2) of R1), 7.41 (ddt, 2H, J 8.5, 7.1, 1.1, CH-3+5 Ph-N(2) of R1), 10.24 (bs, 1H, OH); 13C NMR 20.38 (CH3), 44.4 (CH2-Cq-6), 44.9 (CH2 of R2), 50.8 (CH2-Cq-2), 113.5 (CH-2+6 Ph-N(6) of R1), 117.4 (CH-4 Ph-N(6) of R1), 123.0 (Cq-2), 126.9 (Cq-6), 127.3 (CH-2+6 Ph of R2), 127.4 (CH-4 Ph of R2), 127.7 (Cq-4), 128.63 (CH-4 Ph-N(2) of R1), 128.65 (CH-3+5 Ph of R2), 128.9 (CH-2+6 Ph-N(2) of R1), 129.1 (CH-3+5 Ph-N(6) of R1), 130.1 (CH-5), 130.4 (CH-3+5 Ph-N(2) of R1), 130.9 (CH-3), 138.8 (Cq-1 Ph of R2), 140.6 (Cq-1 Ph-N(2) of R1), 148.6 (Cq-1 Ph-N(6) of R1), 152.2 (Cq-1), 158.7 (C=O); ESI MS m/z 359 [M-PhCH2 + 1]+ (100), 452 [M + 1]+ (47), 474 [M + Na]+ (16), 490 [M + K]+ (2), 926 [2M + Na]+ (20).
- Ligand 3ab: Rf 0.27 (1% MeOH/DCM); colourless solid; m. p. 142.7–142.9 °C; 1H NMR 2.09 (s, 3H, CH3), 4.40 (d, 4H, J 5.8, CH2 of R2), 4.49 (t, 2H, J 5.8, NH-CO), 4.83 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 6.68 (s, 2H, CH-3 and CH-5), 7.16 (dd, 4H, J 8.1, 1.4, CH-2+6 Ph of R1), 7.17 (m, 6H, CH-2+6 and CH-4 Ph of R2), 7.28 (m, 6H, CH-4 Ph of R1 and CH-3+5 Ph of R2), 7.35 (ddt, 4H, J 7.9, 7.4, 1.7, CH-3+5 Ph of R1), 10.02 (bs, 1H, OH); 13C NMR 20.5 (CH3), 44.4 (CH2-Cq-6), 44.8 (CH2 of R2), 49.6 (CH2-Cq-2 and CH2-Cq-6), 124.4 (Cq-2 and Cq-6), 127.2 (CH-4 Ph of R2), 127.3 (CH-2+6 Ph of R2), 127.67 (Cq-6), 127.69 (Cq-4), 128.5 (CH-2+6 Ph of R1), 128.6 (CH-3+5 Ph of R2), 129.9 (CH-3+5 Ph of R1), 130.2 (CH-3 and CH-5), 139.3 (Cq-1 Ph of R2), 141.6 (Cq-1 Ph of R1), 151.5 (Cq-1), 158.0 (C=O); ESI MS m/z 585 [M + 1]+ (43), 607 [M + Na]+ (89), 623 [M + K]+ (15), 1191 [2M + Na]+ (100).
- Ligand 2ac: Rf 0.55 (1% MeOH/DCM); colourless solid; m. p. 134.5–134.6 °C; 1H NMR 2.08 (s, 3H, CH3), 2.73 (t, 2H, J 6.8, CH2-Ph of R2), 3.42 (td, 2H, J 6.8, 5.9, CH2-N of R2), 4.22 (t, 1H, J 5.7, NH-CO), 4.37 (s, 2H, CH2-Cq-6), 4.67 (s, 2H, CH2-Cq-2), 6.33 (d, 1H, J 2.0, CH-3), 6.69 (tt, 1H, J 7.3, 1.0, CH-4 Ph-N(6) of R1), 6.72 (dd, 2H, J 8.6, 1.0, CH-2+6 Ph-N(6) of R1), 6.96 (m, 2H, CH-2+6 Ph-N(2) of R1), 7.02 (dd, 2H, J 8.4, 1.2, CH-2+6 Ph of R2), 7.04 (d, 1H, J 1.8, CH-5), 7.15-7.20 (m, 5H, CH-3+5 Ph-N(6) of R1 and CH-3+5 and CH-4 Ph of R2), 7.34 (m, 3H, CH-3+5 and CH-4 Ph-N(2) of R1), 10.28 (bs, 1H, OH); 13C NMR 20.3 (CH3), 36.0 (CH2-Ph of R2), 42.1 (CH2-N of R2), 44.4 (CH2-Cq-6), 50.5 (CH2-Cq-2), 113.4 (CH-2+6 Ph-N(6) of R1), 117.3 (CH-4 Ph-N(6) of R1), 123.0 (Cq-2), 126.4 (CH-4 Ph of R2), 126.9 (Cq-6), 127.6 (Cq-4), 128.4 (CH-4 Ph-N(2) of R1), 128.5 (CH-2+6 Ph of R2), 128.7 (CH-2+6 Ph-N(2) of R1), 128.8 (CH-3+5 Ph of R2), 129.1 (CH-3+5 Ph-N(6) of R1), 130.0 (CH-5), 130.1 (CH-3+5 Ph-N(2) of R1), 130.8 (CH-3), 138.7 (Cq-1 Ph of R2), 140.5 (Cq-1 Ph-N(2) of R1), 148.6 (Cq-1 Ph-N(6) of R1), 152.1 (Cq-1), 158.6 (C=O); ESI MS m/z 373 [M-PhCH2 + 1]+ (100), 466 [M + 1]+ (55), 489 [M + Na]+ (5), 504 [M + K]+ (1), 954 [2M + Na]+ (15).
- Ligand 3ac: Rf 0.21 (1% MeOH/DCM); colourless solid; m. p. 132.8–132.9 °C; 1H NMR 2.09 (s, 3H, CH3), 2.74 (t, 4H, J 6.9, CH2-Ph of R2), 3.42 (td, 4H, J 6.9, 6.0, CH2-N of R2), 4.42 (t, 2H, J 5.7, NH-CO), 4.37 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 6.65 (d, 2H, J 2.0, CH-3 and CH-5), 7.02 (dd, 4H, J 8.8, 1.4, CH-2+6 Ph of R1), 7.06 (dd, 4H, J 8.5, 1.4, CH-2+6 Ph of R2), 7.16 (tt, 2H, J 7.3, 1.2, CH-4 Ph of R2), 7.20 (ddt 4H, J 8.3, 7.0, 1.2, CH-3+5 Ph of R2), 7.25 (tt, 2H, J 7.3, 1.3, CH-4 Ph of R1), 7.29 (ddt, 4H, J 8.4, 7.1, 1.3, CH-3+5 Ph of R1), 10.02 (bs, 1H, OH); 13C NMR 20.5 (CH3), 36.1 (CH2-Ph of R2), 42.1 (CH2-N of R2), 49.3 (CH2-Cq-2 and CH2-Cq-6), 124.4 (Cq-2 and Cq-6), 126.2 (CH-4 Ph of R2), 127.5 (Cq-4), 127.6 (CH-4 Ph of R1), 128.46 (CH-3+5 Ph of R2), 128.48 (CH-2+6 Ph of R1), 128.7 (CH-2+6 Ph of R2), 129.7 (CH-3+5 Ph of R1), 130.1 (CH-3 and CH-5), 139.1 (Cq-1 Ph of R2), 141.5 (Cq-1 Ph of R1), 151.4 (Cq-1), 157.9 (C=O); ESI MS m/z 613 [M + 1]+ (34), 635 [M + Na]+ (100), 652 [M + K]+ (10).
- Ligand 3ba: Rf 0.47 (1% MeOH/DCM); colourless solid; m. p. 181.5–181.6 °C; 1H NMR 2.24 (s, 3H, CH3), 4.50 (bs, 4H, CH2-Cq-2 and CH2-Cq-6), 4.62 (s, 4H, CH2 of R1), 6.90 (s, 2H, CH-3 and CH-5), 6.99 (bt, 2H, J 7.3, CH-4 Ph of R2), 7.19 (bt 4H, J 7.9, CH-3+5 Ph of R2), 7.30-7.37 (bm, 10H, CH Ph), 7.41 (bt 4H, J 7.7, CH-3+5 Ph of R1), 11.23 (bs, 1H, OH); 13C NMR 20.4 (CH3), 49.7 (CH2-Cq-2 and CH2-Cq-6), 49.8 (CH2- of R1), 119.9 (CH-2+6 Ph of R2), 123.1 (Cq-2 and Cq-6), 123.7 (CH-4 Ph of R2), 127.2 (CH-4 Ph of R1), 128.7 (Cq-4), 128.8 (CH-3+5 Ph of R2), 128.9 (CH-2+6 Ph of R1), 129.2 (CH-3+5 Ph of R1), 132.2 (CH-3 and CH-5), 138.6 (Cq-1 Ph of R1), 138.9 (Cq-1 Ph of R2), 151.6 (Cq-1), 157.2 (C=O); ESI MS m/z 226 [PhNHCONHCH2Ph]+ (28), 360 [M-PhCH2NHCONHPh+1]+ (95), 585 [M + 1]+ (100), 1170 [2M + 1]+ (59).
- Ligand 2bb: Rf 0.26 (3% MeOH/DCM); yellow solid; m. p. 121.0–121.2 °C; 1H NMR 2.21 (s, 3H, CH3), 3.72 (s, 2H, CH2-N(6) of R1), 3.87 (s, 2H, CH2-Cq-6), 4.34 (s, 2H, CH2-Cq-2), 4.45 (d, 2H, J 5.6, CH2-NH of R2), 4.66 (s, 2H, CH2-N(2) of R1), 6.01 (bs, 1H, NH-CO), 6.74 (d, 1H, J 1.3, CH-5), 6.82 (d, 1H, J 1.3, CH-3), 7.17 (dd, 2H, J 7.7, 1.1, CH-2+6 Ph of R2), 7.19-7.24 (m, 5H, CH Ph), 7.28 (m, 2H, 2 CH-4 Ph), 7.33 (m, 6H, CH Ph), 11.34 (bs, 1H, OH); 13C NMR 20.5 (CH3), 44.8 (CH2-Cq-2), 44.9 (CH2 of R2), 50.2 (CH2-N(2) of R1), 51.5 (CH2-Cq-6), 52.6 (CH2-N(6) of R1), 122.4 (Cq-6), 123.7 (Cq-2), 126.8 (CH Ph), 127.2 (CH-2+6 Ph of R2), 127.4 (2 CH Ph), 127.4 (Cq-4), 127.6 (CH Ph), 127.8 (CH Ph), 128.29 (2 CH Ph), 128.33 (2 CH Ph), 128.6 (2 CH Ph), 128.69 (2 CH Ph), 128.72 (CH-5), 129.5 (CH-3), 138.2 (Cq-1 Ph of N(6)-R1), 138.6 (Cq-1 Ph of N(2)-R1), 139.9 (Cq-1 Ph of R2), 153.2 (Cq-1), 158.8 (C=O); ESI MS m/z 480 [M + 1]+ (100), 502 [M + Na]+ (7), 982 [2M + Na]+ (20).
- Ligand 3bb: Rf 0.36 (1% MeOH/DCM); colourless solid; m. p. 152.6–152.7 °C; 1H NMR 2.20 (s, 3H, CH3), 4.39 (d, 4H, J 5.5, CH2-NH of R2), 4.42 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 4.52 (d, 4H, J 5.5, CH2 of R1), 5.35 (bs, 1H, NH-CO), 6.83 (s, 2H, CH-3 and CH-5), 7.14 (d 4H, J 7.4, CH-2+6 Ph of R1), 7.20 (t, 2H, J 7.4, CH-4 Ph of R1), 7.26 (m, 8H, CH-3+5 Ph of R1 and CH-2+6 Ph of R2). 7.29 (t, 2H, J 7.3, CH-4 Ph of R2), 7.35 (dd 4H, J 7.6, 7.3, CH-3+5 Ph of R2), 10.71 (bs, 1H, OH); 13C NMR 20.4 (CH3), 45.0 (CH2 of R2), 46.9 (CH2-Cq-2 and CH2-Cq-6), 50.2 (CH2 of R1), 123.9 (Cq-2 and Cq-6), 127.0 (CH-2+6 Ph of R2), 127.1 (CH-4 Ph of R1), 127.3 (CH-2+6 Ph of R1), 127.6 (CH-4 Ph of R2), 128.2 (Cq-4), 128.5 (CH-3+5 Ph of R1), 128.9 (CH-3+5 Ph of R2), 130.9 (CH-3 and CH-5), 137.1 (Cq-1 Ph of R1), 139.2 (Cq-1 Ph of R2), 151.9 (Cq-1), 159.3 (C=O); ESI MS m/z 613 [M + 1]+ (26), 635 [M + Na]+ (100), 651 [M + K]+ (15).
- Ligand 2bc: Rf 0.22 (3% MeOH/DCM); yellow solid; m. p. 140.9–141.1 °C; 1H NMR 2.21 (s, 3H, CH3), 2.78 (t, 2H, J 7.0, CH2-Ph of R2), 3.49 (td, 2H, J 7.0, 5.7, CH2-N of R2), 3.78 (s, 2H, CH2-N(6) of R1), 3.92 (s, 2H, CH2-Cq-6), 4.30 (s, 2H, CH2-Cq-2), 4.55 (s, 2H, CH2-N(2) of R1), 5.45 (bs, 1H, NH-CO), 6.77 (bs, 1H, CH-5), 6.80 (bs, 1H, CH-3), 7.09 (dd, 2H, J 7.5, 1.1, CH-2+6 Ph of R2), 7.15 (tt, 1H, J 7.3, 1.0, CH-4 Ph of R2), 7.20 (ddt, 2H, J 7.5, 7.2, 1.0, CH-3+5 Ph of R2), 7.27 (m, 4H, CH Ph), 7.29 (dd, 2H, J 7.6, 1.2, CH-2+6 Ph), 7.33 (m, 4H, CH Ph), 11.13 (bs, 1H, OH); 13C NMR 20.6 (CH3), 36.4 (CH2-Ph of R2), 42.3 (CH2-N of R2), 45.2 (CH2-Cq-2), 50.0 (CH2-N(2) of R1), 51.4 (CH2-Cq-6), 52.6 (CH2-N(6) of R1), 122.5 (Cq-6), 123.6 (Cq-2), 126.1 (CH-4 Ph of R2), 127.2 (CH Ph), 127.55 (CH-2+6 Ph), 127.65 (CH Ph), 128.0 (Cq-4), 128.2 (CH Ph), 128.36 (2 CH Ph), 128.39 (CH-3+5 Ph of R2), 128.6 (2 CH Ph), 128.7 (2 CH Ph), 128.8 (CH-2+6 Ph of R2), 128.9 (CH-5), 129.4 (CH-3), 138.2 (Cq-1 Ph of N(2) R2), 138.3 (Cq-1 Ph of N(6) R2), 139.6 (Cq-1 Ph of R2), 153.2 (Cq-1), 159.0 (C=O); ESI MS m/z 387 [M-PhCH2 + 1]+ (8), 494 [M + 1]+ (100), 516 [M + Na]+ (4), 987 [2M + 1]+ (14), 1010 [2M + Na + 1]+ (8).
- Ligand 3bc: Rf 0.34 (1% MeOH/DCM); colourless solid; m. p. 131.6–131.7 °C; 1H NMR 2.24 (s, 3H, CH3), 2.88 (t, 4H, J 7.1, CH2-Ph of R2), 3.49 (bt, 4H, J 7.1, CH2-N of R2), 4.24 (d, 4H, J 4.9, CH2 of R1), 4.34 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 4.89 (bs, 2H, NH-CO), 6.88 (s, 2H, CH-3 and CH-5), 7.12 (d, 4H, J 7.3, CH-2+6 Ph of R1), 7.17 (m, 6H, CH Ph), 7.22-7.28 (m, 10H, CH Ph), 10.79 (bs, 1H, OH); 13C NMR 20.5 (CH3), 36.4 (CH2-Ph of R2), 45.0 (CH2 of R1), 46.6 (CH2-Cq-2 and CH2-Cq-6), 49.2 (CH2-N of R2), 123.8 (Cq-2 and Cq-6), 126.7 (CH Ph), 127.1 (CH Ph), 127.5 (CH-2+6 Ph of R1), 128.1 (Cq-4), 128.5 (2 CH Ph), 128.8 (4 CH Ph), 130.6 (CH-3 and CH-5), 139.09 (Cq-1 Ph), 139.11 (Cq-1 Ph), 151.8 (Cq-1), 159.1 (C=O); ESI MS m/z 641 [M + 1]+ (39), 663 [M + Na]+ (100), 679 [M + K]+ (15).
- Ligand 2ca: Rf 0.24 (1% MeOH/DCM); colourless oil; 1H NMR 2.23 (s, 3H, CH3), 2.82 (t, 2H, J 6.9, CH2-Ph of N(6) R1), 2.93 (m, 4H, CH2-Ph of N(2) R1 and CH2-N of N(6) R1), 3.63 (t, 2H, J 7.5, CH2-N of N(2) R1), 3.95 (s, 2H, CH2-Cq-6), 4.35 (s, 2H, CH2-Cq-2), 6.77 (d, 1H, J 1.6, CH-5), 6.94 (d, 1H, J 1.7, CH-3), 6.97 (tt, 1H, J 7.3, 1.1, CH-4 Ph of R1), 7.14 (dd, 2H, J 8.2, 1.2, CH-2+6 Ph of R2), 7.21 (m, 2H, CH-4 Ph of R1 and CH-4 Ph of R2), 7.24–7.32 (m, 8H, CH-3+5 Ph and CH-2+6 Ph of R1), 7.36 (bd, 2H, J 7.6, CH-2+6 Ph of R1); 13C NMR 20.5 (CH3), 34.4 (CH2-Ph of N(2) R1), 35.4 (CH2-Ph of N(6) R1), 46.4 (CH2-Cq-2), 49.3 (CH2-N of N(6) R1), 49.6 (CH2-N of N(2) R1), 52.0 (CH2-Cq-6), 119.3 (CH-2+6 Ph of R1), 122.1 (CH-4 Ph of R1), 122.3 (Cq-6), 123.8 (Cq-2), 126.6 (CH-4 Ph of R2), 128.5 (Cq-4), 128.5 (CH-4 Ph of R1), 128.58 (2 CH Ph), 128.62 (2 CH Ph), 128.68 (2 CH Ph), 128.73 (2 CH Ph), 129.0 (2 CH Ph), 129.1 (CH-5), 130.1 (CH-3), 138.6 (Cq-1 Ph of N(6) R1), 139. 7 (Cq-1 Ph of N(2) R1), 140.1 (Cq-1 Ph of R2), 153.2 (Cq-1), 156.0 (C=O); ESI MS m/z 494 [M + 1]+ (100), 496 [M + Na]+ (8), 532 [M + K]+ (1), 987 [2M + 1]+ (17), 1010 [2M + Na + 1]+ (17).
- Ligand 3ca: Rf 0.35 (1% MeOH/DCM); yellow solid; m. p. 118.5–118.8°C; 1H NMR 2.30 (s, 3H, CH3), 2.97 (t, 4H, J 6.9, CH2-Ph of R1), 3.60 (t, 4H, J 6.9, CH2-N of R1), 4.45 (bs, 4H, CH2-Cq-2 and CH2-Cq-6), 6.95 (m, 3H, CH Ph), 6.99 (s, 2H, CH-3 and CH-5), 7.15 (m, 6H, CH Ph), 7.28 (m, 7H, CH Ph), 7.36 (m, 4H, CH Ph), 11.35 (bs, 1H, OH); 13C NMR 20.5 (CH3), 34.1 (CH2-Ph of R1), 46.7 (CH2-Cq-2 and CH2-Cq-6), 49.2 (CH2-N of R1), 119.8 (Cq-2 and Cq-6), 123.1 (2 CH-4 Ph), 128.6 (Cq-4), 128.8 (8 CH Ph), 128.96 (2 CH-4 Ph), 129.03 (8 CH Ph), 131.9 (CH-3 and CH-5), 138.8 (Cq-1 Ph of R2), 139.3 (Cq-1 Ph of R1), 153.6 (Cq-1), 158.2 (C=O); ESI MS m/z 494 [M-PhNHCO + 1]+ (23), 613[M + 1]+ (32), 635 [M + Na]+ (100), 651 [M + K]+ (13).
- Ligand 2cb: Rf 0.14 (2% MeOH/DCM); colourless solid; m. p. 90.3–90.5 °C; 1H NMR 2.20 (s, 3H, CH3), 2.77 (t, 2H, J 6.9, CH2-Ph of N(6) R1), 2.86 (t, 2H, J 6.9, CH2-N of N(6) R1), 2.91 (dd, 2H, J 7.8, 7.4, CH2-Ph of N(2) R1), 3.61 (dd, 2H, J 7.7, 7.5, CH2-N of N(2) R1), 3.86 (s, 2H, CH2-Cq-6), 4.30 (s, 2H, CH2-Cq-2), 4.38 (d, 2H, J 5.5, CH2 of R2), 5.66 (bs, 1H, NH-CO), 6.73 (d, 1H, J 1.7, CH-5), 6.89 (d, 1H, J 1.7, CH-3), 7.14 (dd, 2H, J 8.1, 1.2, CH-2+6 Ph), 7.17-7.30 (m, 13H, CH Ph); 13C NMR 20.5 (CH3), 34.8 (CH2-Ph of N(2) R1), 35.5 (CH2-Ph of N(6) R1), 44.8 (CH2 of R2), 45.880 (CH2-Cq-2), 49.5 (CH2-N of N(6) R1), 49.9 (CH2-N of N(2) R1), 52.0 (CH2-Cq-6), 122.2 (Cq-6), 124.0 (Cq-2), 126.3 (CH Ph), 126.6 (CH Ph), 126.9 (CH Ph), 127.4 (2 CH Ph), 128.3 (Cq-4), 128.4 (2 CH Ph), 128.6 (2 CH Ph), 128.69 (2 CH Ph), 128.71 (CH-5), 128.73 (2 CH Ph), 129.0 (2 CH Ph), 129.1 (CH-3), 138.9 (Cq-1 Ph of N(6) R1), 139.6 (Cq-1 Ph of N(2) R1), 139.9 (Cq-1 Ph of R2), 153.2 (Cq-1), 158.5 (C=O); ESI MS m/z 508 [M + 1]+ (100), 530 [M + Na]+ (9), 1037 [2M + Na]+ (100).
- Ligand 3cb: Rf 0.41 (2% MeOH/DCM); colourless solid; m. p. 151.6–152.0 °C; 1H NMR 2.24 (s, 3H, CH3), 2.88 (t, 4H, J 7.1, CH2-Ph of R1), 3.49 (bt, 4H, J 7.0, CH2-N of R1), 4.24 (d, 4H, J 4.4, CH2 of R2), 4.34 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 4.89 (bs, 2H, NH-CO), 6.88 (s, 2H, CH-3 and CH-5), 7.12 (d, 4H, J 7.3, CH-2+6 Ph), 7.17 (m, 6H, CH Ph), 7.25 (m, 10H, CH Ph), 10.79 (bs, 1H, OH); 13C NMR 20.5 (CH3), 34.4 (CH2-Ph of R1), 45.0 (CH2 of R2), 46.6 (CH2-Cq-2 and CH2-Cq-6), 49.2 (CH2-N of R1), 123.8 (Cq-2 and Cq-6), 126.7 (2 CH-4 Ph), 127.1 (2 CH-4 Ph), 127.5 (4 CH Ph), 128.1 (Cq-4), 128.5 (4 CH Ph), 128.8 (8 CH Ph), 130.6 (CH-3 and CH-5), 138.7 (Cq-1 Ph of R1), 139.1 (Cq-1 Ph of R2), 151.8 (Cq-1), 159.1 (C=O); ESI MS m/z 641 [M + 1]+ (18), 663 [M + Na]+ (100), 679 [M + K]+ (14).
- Ligand 2cc: Rf 0.11 (2% MeOH/DCM); colourless oil; 1H NMR 2.204 (s, 3H, CH3), 2.73 (t, 2H, J 7.1, CH2-Ph of R2), 2.84 (t, 2H, J 7.4, CH2-Ph of N(2) R1), 2.87 (dd, 2H, J 7.0, 6.7, CH2-Ph of N(6) R1), 2.96 (dd, 2H, J 7.0, 6.6, CH2-N of N(6) R1), 2.73 (td, 2H, J 7.0, 5.8, CH2-N of R2), 3.61 (bt, 2H, J 7.4, CH2-N of N(2) R1), 3.92 (s, 2H, CH2-Cq-6), 4.24 (s, 2H, CH2-Cq-2), 4.95 (bs, 1H, NH-CO), 6.77 (bs, 1H, CH-5), 6.84 (d, 1H, J 1.6, CH-3), 7.14-7.19 (m, 7H, CH Ph), 7.21-7.24 (m, 4H, CH Ph), 7.2707.31 (m, 4H, CH Ph); 13C NMR 20.5 (CH3), 34.5 (CH2-Ph of N(2) R1), 35.2 (CH2-Ph of N(6) R1), 36.4 (CH2-Ph of R2), 42.1 (CH2-N of R2), 45.9 (CH2-Cq-2), 49.35 (CH2-N of N(6) R1), 49.44 (CH2-N of N(2) R1), 51.6 (CH2-Cq-6), 122.0 (Cq-6), 123.8 (Cq-2), 126.2 (CH-4 Ph), 126.4 (CH-4 Ph), 126.6 (CH-4 Ph), 128.2 (Cq-4), 128.4 (2 CH Ph), 128.6 (2 CH Ph), 128.68 (2 CH Ph), 128.73 (2 CH Ph), 128.80 (2 CH Ph), 128.85 (2 CH Ph), 129.0 (CH-5), 129.4 (CH-3), 138.6 (Cq-1 Ph), 139.4 (Cq-1 Ph), 139.5 (Cq-1 Ph), 153.1 (Cq-1), 158.6 (C=O); ESI MS m/z 522 [M + 1]+ (100), 544 [M + Na]+ (4), 1043 [2M + 1]+ (8), 1066 [2M + Na + 1]+ (2).
- Ligand 3cc: Rf 0.29 (1% MeOH/DCM); colourless solid; m. p. 107.2–107.3 °C; 1H NMR 2.22 (s, 3H, CH3), 2.73 (t, 4H, J 7.1, CH2-Ph of R2), 2.80 (t, 4H, J 7.2, CH2-Ph of R1), 3.35 (td, 4H, J 6.8, 6.1, CH2-N of R2), 3.40 (bd, 4H, J 7.1, CH2-N of R1), 4.28 (s, 4H, CH2-Cq-2 and CH2-Cq-6), 4.67 (bs, 1H, NH-CO), 6.84 (s, 2H, CH-3 and CH-5), 7.12 (m, 8H, CH-2+6 Ph), 7.18 (m, 2H, CH-4 Ph), 7.21-7.28 (m, 10H, CH Ph), 10.77 (bs, 1H, OH); 13C NMR 20.5 (CH3), 34.3 (CH2-Ph of R1), 36.2 (CH2-Ph of R2), 42.1 (CH2-N of R2), 46.6 (CH2-Cq-2 and CH2-Cq-6), 49.1 (CH2-N of R1), 124.0 (Cq-2 and Cq-6), 126.3 (CH Ph), 126.6 (CH Ph), 128.0 (Cq-4), 128.3 (CH Ph), big common signals for CH Ph at 128.5, 128.7, 128.7 and 128.8, 130.5 (CH-3 and CH-5), 139.0 (Cq-1 Ph), 139.2 (Cq-1 Ph), 151.7 (Cq-1), 158.9 (C=O); ESI MS m/z 669 [M + 1]+ (58), 691 [M + Na]+ (100), 707 [M + K]+ (11).
- Ligand 4: Rf 0.30 (DCM); pale red solid; m. p. 149.8–150.0 °C; 1H NMR 2.28 (s, 3H, CH3), 3.80 (bs, 2H, NH), 4.27 (s, 4H, CH2), 6.63 (d, 4H, J 7.9, CH-2+6 Ph of R1), 6.71 (t, 2H, J 7.3, CH-4 Ph of R1), 7.08 (bt, 1H, J 6.7, CH-4 Ph of R2), 7.14 (dd, 4H, J 8.5, 7.4, CH-3+5 Ph of R1), 7.17 (s, 2H, CH-3 and CH-5), 7.28 (m, 4H, CH-2+6 and CH-3+5 Ph of R2); 13C NMR 20.2 (CH3), 43.8 (CH2), 113.1 (CH-2+6 Ph of R1), 117.9 (CH-4 Ph of R1), 118.9 (CH-2+6 Ph of R2), 124.1 (CH-4 Ph of R2), 129.0 (CH-3+5 Ph of R2), 129.2 (CH-3+5 Ph of R1), 129.3 (CH-3 and CH-5), 131.9 (Cq-2 and Cq-6), 136.5 (Cq-4), 137.0 (Cq-1 Ph of R2), 144.6 (Cq-1), 147.7 (Cq-1 Ph of R1), 151.6 (C=O); ESI MS m/z 226 [M-CONHPh-NPh]+ (100), 319 [M-CONPh + 1]+ (14), 438 [M + 1]+ (41), 876 [2M + 1]+ (3).
- Ligand 5: Rf 0.38 (0.5% MeOH/DCM); colourless solid; m. p. 112.6–112.7 °C; 1H NMR 2.16 (s, 3H, CH3), 4.17 (bs, 1H, NH), 4.27 (s, 2H, CH2-Cq-6), 4.96 (s, 2H, CH2-Cq-2), 6.14 (s, 1H, NH-CON), 6.61 (dd, 2H, J 8.4, 0.9, CH-2+6 Ph-N(6) of R1), 6.68 (tt, 1H, J 7.3, 1.0, CH-4 Ph-N(6) of R1), 6.74 (bs, 1H, CH-3), 6.95 (tt, 1H, J 6.8, 1.8, CH-4 Ph), 6.99 (tt, 1H, J 7.4, 1.0, CH-4 Ph of O R2), 7.15, m, 11H, CH-5 and 10 CH Ph), 7.28 (dd, 2H, J 8.4, 0.9, CH-2+6 Ph of O R2), 7.32 (tt, 1H, J 7.4, 1.3, CH-4 Ph), 7.36 (ddd, 2H, J 8.4, 7.0, 1.4, CH-3+5 Ph), 7.64 (bs, 1H, NH-COO); 13C NMR 20.9 (CH3), 43.4 (CH2-Cq-6), 48.5 (CH2-Cq-2), 112.9 (CH-2+6 Ph-N(6) of R1), 117.5 (CH-4 Ph-N(6) of R1), 118.9 (CH-2+6 Ph of O R2), 119.6 (CH-2+6 Ph of N R2), 123.0 (CH-4 Ph), 123.5 (CH-4 Ph of O R2), 128.4 (CH-4 Ph), 128.7 (2 CH Ph), 128.8 (2 CH Ph), 129.0 (2 CH Ph), 129.2 (2 CH Ph), 129.4 (CH-5), 130.1 (CH-3+5 Ph), 130.3 (Cq-2), 130.7 (CH-3), 132.7 (Cq-6), 135.7 (Cq-4), 137.5 (Cq-1 Ph), 138.5 (Cq-1 Ph of N R2), 140.5 (Cq-1 Ph), 145.1 (Cq-1), 148.2 (Cq-1 Ph of N R2), 151.7 (C=O-O), 154.2 (C=O-N); ESI MS m/z 557 [M + 1]+ (98), 579 [M + Na]+ (100), 595 [M + K]+ (14), 1135 [2M + Na]+ (47).
3.4. General Procedure for the Preparation of Ligands 7
- Ligand 6a: 49% yield; Rf 0.65 (1% MeOH/DCM); red solid; m. p. 178.3–178.6 °C; 1H NMR 2.37 (s, 3H, CH3), 4.71 (s, 2H, CH2-Cq-2), 5.08 (s, 2H, CH2-Cq-6), 6.86 (bs, 1H, CH-3), 7.17 (bdd, 2H, J 7.3, 1.0, CH-2+6 Ph-N(2)), 7.28 (bs, 1H, CH-5), 7.30 (bm, 3H, CH-2+6 and CH-4 Ph-N(6)), 7.37 (bm, 3H, CH-3+5 and CH-4 Ph-N(2)), 7.42 (bdd, 2H, J 8.0, 7.5, (bm, 3H, CH-3+5 Ph-N(6)); 13C NMR 20.9 (CH3), 50.0 (CH2-Cq-6), 50.3 (CH2-Cq-2), 118.0 (Cq-2), 122.9 (Cq-6), 125.0 (CH-2+6 Ph-N(6)), 125.5 (CH-3), 127.2 (CH-4 Ph-N(6)), 128.3 (CH-2+6 Ph-N(2)), 128.7 (CH-4 Ph-N(2)), 129.38 (CH-3+5 Ph-N(2)), 129.41 (CH-3+5 Ph-N(6)), 129.6 (CH-5), 134.3 (Cq-4), 141.5 (Cq-1 Ph-N(2)), 144.6 (Cq-1 Ph-N(6)), 145.6 (Cq-1), 149.8 (O=C-O), 150.0 (O=C-Cl); ESI MS m/z 252 [M-NPhCOCl]+ (73), 345 [M-NHPh]+ (100), 438 [M + 1]+ (49), 876 [2M + 1]+ (14).
- Ligand 6c: 39% yield; Rf 0.51 (1% MeOH/DCM); colourless oil; Some NMR signals are duplicated due to hindered rotation; depicted as “A” and “B”; A:B = 1.3:1; 1H NMR 2.26 (s, 3H, CH3, A), 2.28 (s, 3H, CH3, B), 2.96 (m, 4H, CH2-Ph of N(6) R1, A+B), 3.00 (t, 4H, J 7.4, CH2-Ph of N(2) R1, A+B), 3.60 (t, 2H, J 7.8, CH2-N of N(6) R1, B), 3.69 (t, 4H, J 7.6, CH2-N of N(2) R1, A+B), 3.72 (t, 2H, J 7.8, CH2-N of N(6) R1, A), 4.25 (s, 2H, CH2-Cq-2, A), 4.26 (s, 2H, CH2-Cq-2, B), 4.57 (s, 2H, CH2-Cq-6, A), 4.71 (s, 2H, CH2-Cq-6, B), 6.73 (s, 2H, CH-3, A+B), 6.93 (s, 1H, CH-5, B), 7.05 (s, 1H, CH-5, A), 7.20-7.24 (m, 12H, CH Ph, A+B), 7.27-7.33 (m, 8H, CH Ph, A+B); 13C NMR 20.8 (CH3, A), 20.9 (CH3, B), 33.3 (CH2-Ph of N(2) R1, A+B), 33.5 (CH2-Ph of N(6) R1, B), 34.8 (CH2-Ph of N(6) R1, A), 46.6 (CH2-Cq-6, A), 48.26 (CH2-Cq-2, B), 48.30 (CH2-Cq-2, A), 48.7 (CH2-Cq-6, B), 51.4 (CH2-N of N(2) R1, A+B), 51.7 (CH2-N of N(6) R1, B), 52.8 (CH2-N of N(6) R1, A), 117.3 (Cq-2, A), 117.4 (Cq-2, B), 122.9 (Cq-6, B), 123.0 (Cq-6, A), 125.2 (CH-3, B), 125.5 (CH-3, A), 126.7 (CH Ph), 126.8 (CH Ph), 127.5 (CH-5, B), 128.68 (CH Ph), 128.73 (CH Ph), 128.8 (CH Ph), 128.9 (CH Ph), 129.0 (CH Ph), 129.9 (CH-5, A), 134.0 (Cq-4, A+B), 137.6 (Cq-1 Ph-N(6), A), 137.8 (Cq-1 Ph-N(6), B), 138.4 (Cq-1 Ph-N(2), A+B), 145.2 (Cq-1, A), 145.7 (Cq-1, B), 150.1 (O=C-Cl, A+B), 150.1 (O=C-O, A+B); ESI MS m/z 401 [M-COCl + 1]+ (100), 463 [M + 1]+ (1.5), 925 [2M + 1]+ (2).
- Ligand 8a: 2% yield; Rf 0.54 (1% MeOH/DCM); deep red solid; m. p. 135.8–135.9 °C; 1H NMR 2.27 (s, 3H, CH3), 4.46 (s, 2H, CH2-Cq-6), 4.76 (s, 2H, CH2-Cq-2), 6.67 (dd, 2H, J 8.6, 1.0, CH-2+6 Ph-N(6)), 6.71 (tt, 1H, J 7.3, 1.0, CH-4 Ph-N(6)), 6.80 (bs, 1H, CH-3), 7.16 (m, 3H, CH-5 and CH-3+5 Ph-N(6)), 7.31 (tt, 1H, J 7.3, 1.2, CH-4 Ph-N(2)), 7.38 (dd, 2H, J 8.4, 1.2, CH-2+6 Ph-N(2)), 7.44 (dd, 2H, J 8.4, 7.4, CH-3+5 Ph-N(2)); 13C NMR 20.8 (CH3), 42.4 (CH2-Cq-6), 50.6 (CH2-Cq-2), 113.2 (CH-2+6 Ph-N(6)), 117.66 (Cq-2), 117.70 (CH-4 Ph-N(6)), 124.4 (CH-3), 125.3 (CH-2+6 Ph-N(2)), 126.7 (Cq-6), 127.3 (CH-4 Ph-N(2)), 128.9 (CH-5), 129.2 (CH-3+5 Ph-N(6)), 129.4 (CH-3+5 Ph-N(2)), 133.9 (Cq-4), 141.7 (Cq-1 Ph-N(2)), 145.6 (Cq-1), 147.6 (Cq-1 Ph-N(6)), 150.4 (C=O).
- Ligand 7aa: Rf 0.62 (3% MeOH/DCM); colourless solid; m. p. 235.2–235.3 °C; 1H NMR 2.34 (s, 3H, CH3), 4.71 (s, 2H, CH2-Cq-2), 5.12 (s, 2H, CH2-Cq-6), 6.36 (s, 1H, NH), 6.80 (bs, 1H, CH-3), 7.01 (tt, 1H, J 7.4, 1.1, CH-4 Ph of R2), 7.26 (m, 3H, CH Ph), 7.29–7.37 (m, 9H, 8 CH Ph and CH-5 at 7.326), 7.43 (m, 4H, CH Ph); 13C NMR 21.0 (CH3), 46.9 (CH2-Cq-6), 50.4 (CH2-Cq-2), 117.6 (Cq-2), 119.3 (CH-2+6 Ph of R2), 123.0 (CH-4 Ph of R2), 124.6 (CH-3), 125.1 (2 CH Ph), 125.6 (Cq-6), 127.1 (CH-4 Ph), 128.2 (CH-4 Ph), 128.3 (2 CH Ph), 128.8 (2 CH Ph), 129.3 (CH-5), 129.3 (2 CH Ph), 130.2 (2 CH Ph), 134.1 (Cq-4), 138.7 (Cq-1 Ph of R2), 141.3 (Cq-1 Ph of R1), 141.7 (Cq-1 Ph of R1), 145.4 (Cq-1), 150.2 (O=C-O), 154.5 (O=C-N); ESI MS m/z 226 [PhNHCONHPhCH3]+ (52), 345 [M-CONHPh + 1]+ (73), 464 [M + 1]+ (100), 486 [M + Na]+ (5), 928 [2M + 1]+ (3).
- Ligand 7ab: Rf 0.42 (3% MeOH/DCM); colourless solid; m. p. 130.9–131.0 °C; 1H NMR 2.34 (s, 3H, CH3), 4.46 (d, 2H, J 4.7, CH2 of R2), 4.72 (s, 2H, CH2-Cq-2), 4.78 (bs, 1H, NH), 5.08 (s, 2H, CH2-Cq-6), 6.79 (bs, 1H, CH-3), 7.25 (m, 5H, CH Ph), 7.27-7.33 (m, 7H, 6 CH Ph and CH-5 at 7.298), 7.36 (bt, 2H, J 7.6, CH-3+5 Ph), 7.47 (bt, 2H, J 7.7, CH-3+5 Ph); 13C NMR 21.0 (CH3), 44.8 (CH2 of R2), 47.0 (CH2-Cq-6), 50.5 (CH2-Cq-2), 117.6 (Cq-2), 124.4 (CH-3), 125.1 (2 CH Ph), 126.0 (Cq-6), 127.1 (CH-4 Ph), 127.2 (2 CH Ph), 127.3 (2 CH Ph), 127.8 (CH-4 Ph), 128.2 (CH-4 Ph), 128.6 (2 CH Ph), 129.2 (CH-5), 129.3 (CH-3+5 Ph), 130.0 (CH-3+5 Ph), 134.0 (Cq-4), 139.5 (Cq-1 Ph of R2), 141.69 (Cq-1 Ph of R1), 141.73 (Cq-1 Ph of R1), 145.4 (Cq-1), 150.3 (O=C-O), 157.3 (O=C-N); ESI MS m/z 226 [PhNHCONHCH2Ph]+ (90), 345 [M-CONHCH2Ph+1]+ (71), 359 [M-CONPh]+ (68), 478 [M + 1]+ (100), 500 [M + Na]+ (7), 956 [2M + 1]+ (8).
- Ligand 7ac: Rf 0.41 (3% MeOH/DCM); colourless oil; 1H NMR 2.35 (s, 3H, CH3), 2.79 (t, 2H, J 6.8, CH2-Ph of R2), 3.48 (td, 2H, J 6.8, 5.8, CH2-N of R2), 4.40 (t, 1H, J 5.5, NH), 4.70 (s, 2H, CH2-Cq-2), 5.04 (s, 2H, CH2-Cq-6), 6.78 (bs, 1H, CH-3), 7.10 (m, 4H, 2 CH-2+6 Ph), 7.19 (tt, 1H, J 7.4, 1.2, CH-4 Ph), 7.24 (tt, 2H, J 7.4, 1.2, CH-3+5 Ph of R2), 7.26(d, 1H, J 1.1, CH-5), 7.27-7.32 (m, 6H, CH Ph), 7.41 (ddt, 2H, J 8.4, 7.4, 1.9, CH-3+5 Ph); 13C NMR 21.0 (CH3), 36.1 (CH2-Ph of R2), 42.0 (CH2-N of R2), 46.7 (CH2-Cq-6), 50.4 (CH2-Cq-2), 117.6 (Cq-2), 124.3 (CH-3), 125.1 (2 CH Ph), 126.1 (Cq-6), 126.3 (CH-4 Ph), 127.1 (CH-4 Ph), 127.6 (CH-4 Ph), 128.2 (2 CH Ph), 128.5 (2 CH Ph), 128.8 (2 CH Ph), 129.1 (CH-5), 129.3 (CH-3+5 Ph of R1), 129.8 (2 CH Ph), 133.9 (Cq-4), 139.2 (Cq-1 Ph of R2), 141.6 (Cq-1 Ph of R1), 141.7 (Cq-1 Ph of R1), 145.3 (Cq-1), 150.3 (O=C-O), 157.2 (O=C-N); ESI MS m/z 492 [M + 1]+ (10), 514 [M + Na]+ (35), 1006 [2M + Na]+ (47).
- Ligand 7bb: Rf 0.43 (2% MeOH/DCM); colourless solid; m. p. 109.8–110.4 °C; 1H NMR 2.24 (s, 3H, CH3), 4.24 (s, 2H, CH2-Cq-2), 4.45 (s, 2H, CH2 of R2), 4.54 (s, 2H, CH2-Cq-6), 4.62 (s, 2H, CH2-N(6) of R1), 4.64 (s, 2H, CH2-N(2) of R1), 4.97 (bs, 1H, NH), 6.71 (bs, 1H, CH-3), 6.98 (bs, 1H, CH-5), 7.17 (dd, 2H, J 7.8, 1.2, CH-2+6 Ph), 7.21 (tt, 1H, J 7.4, 1.2, CH-4 Ph), 7.25 (tt, 2H, J 7.5, 1.2, CH-3+5 Ph of R2), 7.27 (m, 3H, CH Ph), 7.31–7.36 (m, 7H, CH Ph); 13C NMR 20.8 (CH3), 44.88 (CH2 of R2), 44.92 (CH2-Cq-6), 46.5 (CH2-Cq-2), 50.9 (s, 2H, CH2-N(6) of R1), 52.5 (s, 2H, CH2-N(2) of R1), 116.9 (Cq-2), 124.4 (Cq-6), 124.9 (CH-3), 127.0 (CH-4 Ph), 127.4 (2 CH Ph), 127.4 (CH-4 Ph), 127.4 (CH-4 Ph), 128.1 (CH-5), 128.2 (2 CH Ph), 128.3 (2 CH Ph), 128.4 (2 CH Ph), 128.7 (2 CH Ph), 128.9 (2 CH Ph), 134.0 (Cq-4), 135.2 (Cq-1 Ph of N(2) R1), 137.7 (Cq-1 Ph of N(6) R1), 139.5 (Cq-1 Ph of R2), 145.2 (Cq-1), 150.5 (O=C-O), 158.3 (O=C-N); ESI MS m/z 373 [M-CONCH2Ph]+ (93), 506 [M + 1]+ (100), 528 [M + Na]+ (9), 1012 [2M + 1]+ (38).
- Ligand 7bc: Rf 0.39 (2% MeOH/DCM); colourless oil; 1H NMR 2.247 (s, 3H, CH3), 2.77 (t, 2H, J 6.9, CH2-Ph of R2), 3.50 (bt, 2H, J 6.8, CH2-N of R2), 4.26 (s, 2H, CH2-Cq-2), 4.46 (s, 2H, CH2-Cq-6), 4.54 (s, 2H, CH2-N(6) of R1), 4.63 (bs, 1H, NH), 4.66 (s, 2H, CH2-N(2) of R1), 6.71 (bs, 1H, CH-3), 6.94 (bs, 1H, CH-5), 7.06 (dd, 2H, J 7.7, 1.2, CH-2+6 Ph), 7.12 (tt, 1H, J 7.3, 1.3, CH-4 Ph), 7.19 (m, 4H, CH-3+5 Ph of R2 and 2 CH Ph), 7.25 (tt, 1H, J 7.3, 1.1, CH-4 Ph), 7.29–7.37 (m, 7H, CH Ph); 13C NMR 20.8 (CH3), 36.3 (CH2-Ph of R2), 42.2 (CH2-N of R2), 44.9 (CH2-Cq-6), 46.6 (CH2-Cq-2), 50.7 (CH2-N(6) of R1), 52.5 (s, 2H, CH2-N(2) of R1), 116.8 (Cq-2), 124.5 (Cq-6), 124.8 (CH-3), 126.1 (CH-4 Ph), 127.3 (2 CH Ph), 127.4 (CH-4 Ph), 128.1 (CH-5), 128.2 (CH-4 Ph), 128.3 (2 CH Ph), 128.49 (2 CH Ph), 128.70 (2 CH Ph), 128.71 (2 CH Ph), 128.9 (2 CH Ph), 133.9 (Cq-4), 135.3 (Cq-1 Ph of N(2) R1), 137.6 (Cq-1 Ph of N(6) R1), 139.3 (Cq-1 Ph of R2), 145.2 (Cq-1), 150.6 (O=C-O), 158.3 (O=C-N); ESI MS m/z 520 [M + 1]+ (14), 542 [M + Na]+ (48), 558 [M + K]+ (2), 1062 [2M + Na]+ (100).
- Ligand 7ca: Rf 0.60 (3% MeOH/DCM); colourless solid; m. p. 133.1-133.2 °C; 1H NMR 2.27 (s, 3H, CH3), 2.92 (t, 2H, J 7.2, CH2-Ph of N(6) R1), 3.00 (t, 2H, J 7.4, CH2-Ph of N(2) R1), 3.61 (t, 2H, J 7.2, CH2-N of N(6) R1), 3.68 (t, 2H, J 7.4, CH2-N of N(2) R1), 4.25 (s, 2H, CH2-Cq-2), 4.56 (s, 2H, CH2-Cq-6), 6.53 (bs, 1H, NH), 6.72 (bs, 1H, CH-3), 6.98 (bt, 1H, J 7.1, CH-4 Ph), 7.02 (bs, 1H, CH-5), 7.24 (m, 8H, CH Ph), 7.30 (m, 6H, CH Ph); 13C NMR 20.82 (CH3), 33.2 (CH2-Ph of N(2) R1), 34.6 (CH2-Ph of N(6) R1), 45.4 (CH2-Cq-6), 48.3 (CH2-Cq-2), 49.8 (CH2-N of N(6) R1), 51.3 (CH2-N of N(2) R1), 117.2 (Cq-2), 128.4 (CH-2+6 Ph of R2), 122.6 (CH-4 Ph of R2), 124.4 (Cq-6), 125.1 (CH-3), 126.6 (CH-4 Ph), 126.7 (CH-4 Ph), 128.70 (2 CH Ph), 128.71 (2 CH Ph), 128.78 (2 CH Ph), 128.79 (2 CH Ph), 128.97 (2 CH Ph), 129.03 (CH-5), 134.0 (Cq-4), 138.3 (Cq-1 Ph of N(2) R1), 139.3 (Cq-1 Ph of N(6) R1 and Cq-1 Ph of R2), 145.5 (Cq-1), 150.1 (O=C-O), 155.8 (O=C-N); ESI MS m/z 520 [M + 1]+ (11), 542 [M + Na]+ (54), 558 [M + K]+ (4), 1062 [2M + Na]+ (100).
- Ligand 7cb: Rf 0.39 (3% MeOH/DCM); colourless oil; 1H NMR 2.236 (s, 3H, CH3), 2.90 (dd, 2H, J 7.6, 7.4, CH2-Ph of N(6) R1), 2.98 (dd, 2H, J 7.6, 7.4, CH2-Ph of N(2) R1), 3.57 (dd, 2H, J 7.6, 7.4, CH2-N of N(6) R1), 3.66 (dd, 2H, J 7.6, 7.4, CH2-N of N(2) R1), 4.23 (s, 2H, CH2-Cq-2), 4.36 (s, 2H, CH2 of R2), 4.49 (s, 2H, CH2-Cq-6), 4.71 (bs, 1H, NH), 6.68 (bs, 1H, CH-3), 6.95 (bs, 1H, CH-5), 7.19 (m, 5H, CH Ph), 7.24 (m, 5H, CH Ph), 7.28 (m, 5H, CH Ph); 13C NMR 20.8 (CH3), 33.2 (CH2-Ph of N(2) R1), 34.8 (CH2-Ph of N(6) R1), 44.8 (CH2 of R2), 46.0 (CH2-Cq-6), 48.2 (CH2-Cq-2), 49.9 (CH2-N of N(6) R1), 51.3 (CH2-N of N(2) R1), 117.1 (Cq-2), 124.6 (Cq-6), 124.7 (CH-3), 126.4 (CH-4 Ph), 126.7 (CH-4 Ph), 127.0 (CH-4 Ph), 127.5 (2 CH Ph), 128.1 (CH-5), 128.4 (2 CH Ph), 128.6 (2 CH Ph), 128.7 (2 CH Ph), 128.8 (2 CH Ph), 128.9 (2 CH Ph), 133.9 (Cq-4), 138.4 (Cq-1 Ph of R2), 139.1 (Cq-1 Ph of N(2) R1), 139.6 (Cq-1 Ph of N(6) R1), 145.3 (Cq-1), 150.1 (O=C-O), 158.0 (O=C-N); ESI MS m/z 534 [M+1]+ (14), 556 [M + Na]+ (83), 572 [M + K]+ (5), 1090 [2M + Na]+ (100).
- Ligand 7cc: Rf 0.40 (3% MeOH/DCM); colourless oil; 1H NMR 2.237 (s, 3H, CH3), 2.74 (t, 2H, J 7.0, CH2-Ph of R2), 2.82 (dd, 2H, J 7.7, 7.4, CH2-Ph of N(6) R1), 3.00 (dd, 2H, J 7.7, 7.3, CH2-Ph of N(2) R1), 3.44 (dd, 2H, J 7.0, 6.8, CH2-N of R2), 3.46 (dd, 2H, J 7.8, 7.5, CH2-N of N(6) R1), 3.68 (dd, 2H, J 7.7, 7.2, CH2-N of N(2) R1), 4.24 (s, 2H, CH2-Cq-2), 4.40 (bs, 1H, NH), 4.42 (s, 2H, CH2-Cq-6), 6.68 (bs, 1H, CH-3), 6.91 (bs, 1H, CH-5), 7.14 (m, 4H, CH Ph), 7.19 (m, 2H, 2 CH-4 Ph), 7.24 (m, 5H, CH Ph), 7.29 (m, 4H, CH Ph); 13C NMR 20.8 (CH3), 33.3 (CH2-Ph of N(2) R1), 34.7 (CH2-Ph of N(6) R1), 36.2 (CH2-Ph of R2), 42.0 (CH2-N of R2), 44.8 (CH2-Cq-6), 48.3 (CH2-Cq-2), 49.7 (CH2-N of N(6) R1), 51.3 (CH2-N of N(2) R1), 117.0 (Cq-2), 124.6 (CH-3), 124.8 (Cq-6), 126.2 (CH-4 Ph), 126.4 (CH-4 Ph), 126.7 (CH-4 Ph), 128.2 (CH-5), 128.5 (2 CH Ph), 128.6 (2 CH Ph), 128.7 (2 CH Ph), 128.77 (2 CH Ph), 128.80 (2 CH Ph), 128.85 (2 CH Ph), 133.8 (Cq-4), 138.4 (Cq-1 Ph of N(2) R1), 139.0 (Cq-1 Ph of N(6) R1), 139.4 (Cq-1 Ph of R2), 145.3 (Cq-1), 150.16 (O=C-O), 158.0 (O=C-N); ESI MS m/z 548 [M + 1]+ (18), 570 [M + Na]+ (100), 586 [M + K]+ (7), 1118 [2M + Na]+ (99).
3.5. Crystallography
3.6. Isothermal Titration Calorimetry (ITC)
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Sample Availability
References
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Entry | Conditions a | Products | ||||
---|---|---|---|---|---|---|
2 | Yield, % | 3 | Yield, % | Total, % | ||
1 | DIPEA, 1a:CC 1:1.5, toluene, 24 h | 2aa | 15 | 3aa | - | 51 b |
2 | 1a:CC 1:1, benzene, 2 h | 19 | traces | 19 | ||
3 | 1a:CC 1:2, toluene, 24 h | 39 | 13 | 52 | ||
4 | 1a:CC 1:3, toluene, 24 h | 35 | 22 | 57 | ||
5 | 1a:CC 1:1, toluene, 2 h | 2ab | 30 | 3ab | traces | 30 |
6 | 1a:CC 1:2, toluene, 24 h | 32 | 23 | 55 | ||
7 | 1a:CC 1:1, benzene, 2 h | 2ac | traces | 3ac | - | - |
8 | 1a:CC 1:2, benzene, 2 h | 17 | traces | 17 | ||
9 | 1a:CC 1:2, toluene, 2 h | 39 | 8 | 47 | ||
10 | 1a:CC 1:2, DCE, 2 h | 30 | 32 | 62 | ||
11 | 1b:CC 1:2, toluene, 24 h | 2bac | 21 | 3ba | - | 21 |
12 | 1b:CC 1:2, benzene, 24 h | 37 | 7 | 44 | ||
13 | 1b:CC 1:4, toluene, 24 h | 19 | 17 | 36 | ||
14 | 1b:CC 1:1, toluene, 2 h | 2bb | 34 | 3bb | traces | 34 |
15 | 1b:CC 1:2, toluene, 24 h | - | 46 | 46 | ||
16 | 1b:CC 1:1, benzene, 2 h | 2bc | 26 | 3bc | - | 26 |
17 | 1b:CC 1:2, benzene, 2 h | 16 | - | 16 | ||
18 | 1b:CC 1:2, toluene, 24 h | 17 | 28 | 45 | ||
19 | 1b:CC 1:2, DCE, 2 h | 8 | 27 | 35 | ||
20 | 1c:CC 1:1.5, toluene, 24 h | 2ca | 44 | 3ca | 17 | 61 |
21 | 1c:CC 1:2, toluene, 24 h | 20 | 43 | 63 | ||
22 | 1c:CC 1:2, toluene, 24 h | 2cb | 15 | 3cb | 43 | 58 |
23 | 1c:CC 1:3, toluene, 4 h | - | 43 | 43 | ||
24 | 1c:CC 1:1, DCE, 2 h | 7 | traces | 7 | ||
25 | 1c:CC 1:2, DCE, 2 h | 18 | 16 | 34 | ||
26 | 1c:CC 1:1, benzene, 2 h | 2cc | 42 | 3cc | 21 | 63 |
27 | 1c:CC 1:2, benzene, 2 h | - | 19 | 19 | ||
28 | 1c:CC 1:2, toluene, 24 h | 20 | 39 | 59 | ||
29 | 1c:CC 1:2, DCE, 2 h | - | 38 | 38 |
Lig. | CH-3 CH-3 | CH-5 CH-5 | CH2-Cq-2 CH2-Cq-2 | CH2-Cq-6 CH2-Cq-6 |
---|---|---|---|---|
2aa | 6.372 130.90 | 7.042 130.14 | 4.773 50.47 | 4.363 44.54 |
3aa | 6.667/131.03 | 4.876/49.40 | ||
2ab | 6.344 130.90 | 7.042 130.08 | 4.723 50.81 | 4.372 44.43 |
3ab | 6.678/130.23 | 4.828/49.63 | ||
2ac | 6.327 130.83 | 7.038 129.99 | 4.667 50.51 | 4.374 44.36 |
3ac | 6.647/130.07 | 4.778/49.29 | ||
2ba * | 6.843 130.79 | 6.800 129.16 | 4.362 45.21 | 4.015 51.62 |
3ba | 6.900/132.16 | 4.501 (br)/49.72 | ||
2bb | 6.822 129.46 | 6.741 128.72 | 4.336 44.76 | 3.869 51.46 |
3bb | 6.833/130.94 | 4.416/46.94 | ||
2bc | 6.802 129.43 | 6.770 128.93 | 4.295 45.21 | 3.922 51.44 |
3bc | 6.879/130.64 | 4.893/46.64 | ||
2ca | 6.939 130.11 | 6.771 129.08 | 4.349 46.39 | 3.952 52.00 |
3ca | 6.989/131.93 | 4.446/46.66 | ||
2cb | 6.886 129.06 | 6.726 128.71 | 4.297 45.80 | 3.861 52.00 |
3cb | 6.879/130.64 | 4.335/46.64 | ||
2cc | 6.840 129.36 | 6.769 129.04 | 4.244 45.87 | 3.925 51.62 |
3cc | 6.844/130.46 | 4.284/46.57 |
Starting Chloride | Products | |||||
---|---|---|---|---|---|---|
Compd. | Yield, % | Compd. | Yield, % | Compd. | Yield, % | |
6a | 7aa | 73 | 7ab | 84 | 7ac | 84 |
6b | 7ba a | 87 | 7bb | 79 | 7bc | 71 |
6c | 7ca | 72 | 7cb | 71 | 7cc | 68 |
Lig. | CH-3 CH-3 | CH-5 CH-5 | CH2-Cq-2 CH2-Cq-2 | CH2-Cq-6 CH2-Cq-6 |
---|---|---|---|---|
7aa | 6.798 124.56 | 7.326 129.30 | 4.710 50.43 | 5.120 46.86 |
7ab | 6.791 124.35 | 7.298 129.15 | 4.715 50.49 | 5.084 47.05 |
7ac | 6.777 124.26 | 7.260 129.09 | 4.704 50.45 | 5.037 46.74 |
7ba * | 6.749 125.33 | 7.015 129.30 | 4.279 46.56 | 4.595 45.33 |
7bb | 6.709 124.87 | 6.978 128.11 | 4.240 46.54 | 4.537 44.92 |
7bc | 6.707 124.80 | 6.938 128.13 | 4.260 46.57 | 4.464 44.87 |
7ca | 6.720 125.10 | 7.020 129.03 | 4.251 48.26 | 4.556 45.38 |
7cb | 6.685 124.69 | 6.948 128.09 | 4.229 48.24 | 4.490 44.95 |
7cc | 6.681 124.62 | 6.907 128.16 | 4.244 48.26 | 4.425 44.80 |
Cell Contents [mM] | Syringe Contents [mM] | ΔH [kJ·mol−1] | Ka.106 [M−1] | n |
---|---|---|---|---|
EDTA 0.15 | CaCl2 0.95 | −16.54 ± 0.36 | 1.30 ± 4.91 | 0.886 |
2ba 0.20 | PbCl2 1.20 | 62.95 ± 9.85 | 0.31 ± 0.25 | 0.869 |
2ba 0.20 | CaCl2 1.20 | −100.00 ± 7.72 | 0.024 ± .059 | 1.856 |
2bc 0.20 | PbCl2 1.10 | −16.62 ± 0.44 | 0.14 ± 0.33 | 0.545 |
2cb 0.30 | PbCl2 1.50 | −37.27 ± 20.16 | 0.17 ± 0.60 | 0.201 * |
3bb 0.25 | KCl 1.10 | −13.48 ± 0.45 | 1.00 ± 0.58 | 0.444 |
3cc 0.20 | KCl 1.20 | −16.06 ± 1.48 | 0.54 ± 0.71 | 0.424 |
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Todorova, S.E.; Rusew, R.I.; Shivachev, B.L.; Kurteva, V.B. Polydentate N,O-Ligands Possessing Unsymmetrical Urea Fragments Attached to a p-Cresol Scaffold. Molecules 2023, 28, 6540. https://doi.org/10.3390/molecules28186540
Todorova SE, Rusew RI, Shivachev BL, Kurteva VB. Polydentate N,O-Ligands Possessing Unsymmetrical Urea Fragments Attached to a p-Cresol Scaffold. Molecules. 2023; 28(18):6540. https://doi.org/10.3390/molecules28186540
Chicago/Turabian StyleTodorova, Stanislava E., Rusi I. Rusew, Boris L. Shivachev, and Vanya B. Kurteva. 2023. "Polydentate N,O-Ligands Possessing Unsymmetrical Urea Fragments Attached to a p-Cresol Scaffold" Molecules 28, no. 18: 6540. https://doi.org/10.3390/molecules28186540