Next Article in Journal
[18F]FEPPA a TSPO Radioligand: Optimized Radiosynthesis and Evaluation as a PET Radiotracer for Brain Inflammation in a Peripheral LPS-Injected Mouse Model
Next Article in Special Issue
One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination
Previous Article in Journal
Room-Temperature Fabricated Thin-Film Transistors Based on Compounds with Lanthanum and Main Family Element Boron
Previous Article in Special Issue
Catalytic Enantioselective Addition of Organozirconium Reagents to Aldehydes
Article

Chiral 2-Aminobenzimidazole as Bifunctional Catalyst in the Asymmetric Electrophilic Amination of Unprotected 3-Substituted Oxindoles

Departamento de Química Orgánica and Instituto de Síntesis Orgánica (ISO), Facultad de Ciencias, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
*
Author to whom correspondence should be addressed.
Molecules 2018, 23(6), 1374; https://doi.org/10.3390/molecules23061374
Received: 9 May 2018 / Revised: 4 June 2018 / Accepted: 5 June 2018 / Published: 6 June 2018
(This article belongs to the Special Issue Stereogenic Centers)
The use of readily available chiral trans-cyclohexanediamine-benzimidazole derivatives as bifunctional organocatalysts in the asymmetric electrophilic amination of unprotected 3-substituted oxindoles is presented. Different organocatalysts were evaluated; the most successful one contained a dimethylamino moiety (5). With this catalyst under optimized conditions, different oxindoles containing a wide variety of substituents at the 3-position were aminated in good yields and with good to excellent enantioselectivities using di-tert-butylazodicarboxylate as the aminating agent. The procedure proved to be also efficient for the amination of 3-substituted benzofuranones, although with moderate results. A bifunctional role of the catalyst, acting as Brønsted base and hydrogen bond donor, is proposed according to the experimental results observed. View Full-Text
Keywords: organocatalysis; electrophilic amination; benzimidazoles; asymmetric catalysis; oxindoles organocatalysis; electrophilic amination; benzimidazoles; asymmetric catalysis; oxindoles
Show Figures

Figure 1

MDPI and ACS Style

Benavent, L.; Baeza, A.; Freckleton, M. Chiral 2-Aminobenzimidazole as Bifunctional Catalyst in the Asymmetric Electrophilic Amination of Unprotected 3-Substituted Oxindoles. Molecules 2018, 23, 1374. https://doi.org/10.3390/molecules23061374

AMA Style

Benavent L, Baeza A, Freckleton M. Chiral 2-Aminobenzimidazole as Bifunctional Catalyst in the Asymmetric Electrophilic Amination of Unprotected 3-Substituted Oxindoles. Molecules. 2018; 23(6):1374. https://doi.org/10.3390/molecules23061374

Chicago/Turabian Style

Benavent, Llorenç, Alejandro Baeza, and Megan Freckleton. 2018. "Chiral 2-Aminobenzimidazole as Bifunctional Catalyst in the Asymmetric Electrophilic Amination of Unprotected 3-Substituted Oxindoles" Molecules 23, no. 6: 1374. https://doi.org/10.3390/molecules23061374

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop