Cooperative Catalysis and Activation with N‐Heterocyclic Carbenes. Issue 48 (20th October 2016)

• Record Type: Journal Article
• Authors: Wang, Michael H.; Scheidt, Karl A.
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 48(2016)
• Page Start: 14912
• Page End: 14922
• Publication Date: 2016-10-20
• Subjects: cooperative catalysis -- N-heterocyclic carbenes -- organocatalysis -- synthetic methods; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201605319
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: N‐Heterocyclic carbene (NHC) catalysis has emerged as a powerful stratagem in organic synthesis to construct complex molecules primarily by polarity reversal (umpolung) approaches. These unique Lewis bases have been used to generate acyl anions, enolates, and homoenolates in catalytic fashion. Recently, a new strategy has emerged that dramatically expands the synthetic utility of carbene catalysis by leveraging additional activation modes: cooperative catalysis. The careful selection and balance of cocatalysts have led to enhanced reactivity, increased yields, and improved stereoselectivity. In certain cases, these catalytic additives have changed the regioselectivity or diastereoselectivity. This Minireview highlights new advances in NHC cooperative catalysis and surveys the evolution of this field. Abstract : N‐Heterocyclic carbene (NHC) catalysis is a versatile and powerful strategy to construct complex molecules. To extend and enhance the reactivity of these nucleophiles, cooperative catalysis and related activation approaches have been developed by integrating complementary modes (Lewis/Brønsted acidity, transition‐metal processes, photoredox). Recent contributions are summarized in this Minireview.