Axially Chiral Imidodiphosphoric Acid Catalyst for Asymmetric Sulfoxidation Reaction: Insights on Asymmetric Induction

• Published in: Angewandte Chemie International Edition Vol. 53; no. 17; pp. 4432 - 4436
• Main Authors: Jindal, Garima, Sunoj, Raghavan B.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 22.04.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: asymmetric catalysis; Asymmetry; Brønsted acids; Catalysis; Catalysts; Chemical bonds; density functional calculations; Diphosphonates - chemistry; Fittings; Holes; Mathematical models; Models, Molecular; Molecular Structure; noncovalent interactions; Oxygen atoms; Pocket; Recognition; Stereoisomerism; Sulfoxides - chemistry; transition states; density functional calculations; asymmetric catalysis; transition states; noncovalent interactions; Brønsted acids
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201309532

Insights into chiral induction for an asymmetric sulfoxidation reaction involving a single oxygen atom transfer are gained through analyzing the stereocontrolling transition states. The fitting of the substrate into the chiral cavity of a new class of imidodiphosphoric Brønsted acids, as well as weak CH⋅⋅⋅π and CH⋅⋅⋅O noncovalent interactions, are identified as responsible for the observed chiral induction. Turn the stereo up: The first transition‐state (TS) model for a new class of axially chiral imidodiphosphoric acid catalysts in the title reaction is proposed using DFT(M06‐2X) calculations. The recognition of the substrate in the chiral pocket and a series of weak noncovalent interactions are responsible for stereoinduction. This stereoelectronic model differs from the commonly employed models which rely on steric interactions.