Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions
نویسندگان
چکیده
N-Heterocyclic carbenes (NHCs) have emerged as a powerful class of organocatalysts that mediate a variety of organic transformations. The Benzoin reaction constitutes one of the earliest known carbon-carbon bond-forming reactions catalysed by NHCs. The rapid growth of NHC catalysis in general has resulted in the development of a variety of benzoin and benzoin-type reactions. An overview of such NHC-catalysed benzoin reactions is presented.
منابع مشابه
Correction: Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions
[This corrects the article DOI: 10.3762/bjoc.12.47.].
متن کاملInsights into the Competing Mechanisms and Origin of Enantioselectivity for N-Heterocyclic Carbene-Catalyzed Reaction of Aldehyde with Enamide
Hydroacylation reactions and aza-benzoin reactions have attracted considerable attention from experimental chemists. Recently, Wang et al. reported an interesting reaction of N-heterocyclic carbene (NHC)-catalyzed addition of aldehyde to enamide, in which both hydroacylation and aza-benzoin reactions may be involved. Thus, understanding the competing relationship between them is of great intere...
متن کاملN-heterocyclic carbene catalysed asymmetric cross-benzoin reactions of heteroaromatic aldehydes with trifluoromethyl ketones.
A new triazolium salt derived N-heterocyclic carbene catalyses an asymmetric cross-benzoin-type reaction of heteroaromatic aldehydes and various trifluoromethyl ketones in good to excellent yields (69-96%) and moderate to good enantioselectivities (ee = 39-85%). Up to 99% ee can be achieved by recrystallisation.
متن کاملRate and Equilibrium Constants for the Addition of N‐Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2‐Substituent Effect†
Rate and equilibrium constants for the reaction between N-aryl triazolium N-heterocyclic carbene (NHC) precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow in...
متن کاملTheoretical investigation on the chemoselective N-heterocyclic carbene-catalyzed cross-benzoin reactions.
A density functional theory study was performed to understand the detailed mechanisms of the cross-benzoin reactions catalyzed by N-heterocyclic carbene (NHC) species. Our theoretical study predicted that the first H-transfer operates with water in solution as a mediator, and the second H-transfer undergoes a concerted mechanism rather than a stepwise one. In addition, the chemoselectivity of t...
متن کامل