Economy of Catalyst Synthesis—Convenient Access to Libraries of Di- and Tetranaphtho Azepinium Compounds
AbstractEfficient optimization procedures in chiral catalysis are usually linked to a straightforward strategy to access groups of structurally similar catalysts required for fine-tuning. The ease of building up such ligand libraries can be increased when the structure-modifying step (introduction of a substituent) is done at a later stage of the synthesis. This is demonstrated for the extended family of di- and tetranaphtho azepinium compounds, widely used as chiral phase transfer catalysts (PTC). Using 2,6-diiodo-4,5-dihydro-3H-dinaphtho[2,1-c:1′,2′-e]azepine and 4,8-diiodo-6,7-dihydro-5H-dibenzo[c,e]azepine, respectively, as key intermediates, 18 spiro-azepinium compounds were synthesized in a total yield of 25–42% over 6–7 steps from 1,1′-binaphthyl-2,2′-dicarboxylic acid or diphenic acid, respectively. The replacement of iodo groups with aryl substituents was performed as the last or the penultimate step of the synthesis. View Full-Text
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Tharamak, S.; Knittl-Frank, C.; Manaprasertsak, A.; Pengsook, A.; Suchy, L.; Schuller, P.; Happl, B.; Roller, A.; Widhalm, M. Economy of Catalyst Synthesis—Convenient Access to Libraries of Di- and Tetranaphtho Azepinium Compounds. Molecules 2018, 23, 750.
Tharamak S, Knittl-Frank C, Manaprasertsak A, Pengsook A, Suchy L, Schuller P, Happl B, Roller A, Widhalm M. Economy of Catalyst Synthesis—Convenient Access to Libraries of Di- and Tetranaphtho Azepinium Compounds. Molecules. 2018; 23(4):750.Chicago/Turabian Style
Tharamak, Sorachat; Knittl-Frank, Christian; Manaprasertsak, Auraya; Pengsook, Anchulee; Suchy, Lydia; Schuller, Philipp; Happl, Barbara; Roller, Alexander; Widhalm, Michael. 2018. "Economy of Catalyst Synthesis—Convenient Access to Libraries of Di- and Tetranaphtho Azepinium Compounds." Molecules 23, no. 4: 750.
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