Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions.

Beilstein J Org Chem

Organic Chemistry Section, CSIR-National Institute for Interdisciplinary Science and Technology,Trivandrum 695 019, India.; ; Tel: +91 471 2490406.

Published: June 2016

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.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4901930PMC
http://dx.doi.org/10.3762/bjoc.12.47DOI Listing

Publication Analysis

Top Keywords

nhc-catalysed benzoin
8
benzoin reactions
8
advances n-heterocyclic
4
n-heterocyclic carbene
4
carbene nhc-catalysed
4
benzoin
4
reactions
4
reactions n-heterocyclic
4
n-heterocyclic carbenes
4
carbenes nhcs
4

Similar Publications

Practical Synthesis of C-1 Deuterated Aldehydes Enabled by NHC Catalysis.

Nat Catal

October 2019

State Key Laboratory of Bioengineering Reactor, and Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science & Technology, 130 Meilong Road, Shanghai, 200237, China.

The recent surge in applications of deuterated pharmaceutical agents has created an urgent demand for synthetic methods that efficiently generate deuterated building blocks. Here we show that N-heterocyclic carbenes (NHC) promote a reversible hydrogen-deuterium exchange (HDE) reaction with simple aldehydes, which leads to a practical approach to synthetically valuable C-1 deuterated aldehydes. The reactivity of the well-established NHC catalysed formation of Breslow intermediates from aldehydes is reengineered to overcome the overwhelmingly kinetically favorable, irreversible benzoin condensation reaction and achieve the critical reversibility to drive the formation of desired deuterated products when an excess of DO is employed.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

NHC-catalysed benzoin condensation - is it all down to the Breslow intermediate?

Chem Sci

October 2015

Organische Chemie , Universität Hamburg, Martin-Luther-King-Platz 6 , Germany . Email:

The Breslow catalytic cycle describing the benzoin condensation promoted by N-heterocyclic carbenes (NHC) as proposed in the late 1950s has since then been tried by generations of physical organic chemists. Emphasis has been laid on proofing the existence of an enaminol like structure (Breslow intermediate) that explains the observed umpolung of an otherwise electrophilic aldehyde. The present study is not focusing on spectroscopic elucidation of a thiazolydene based Breslow intermediate but rather tries to clarify if this key-intermediate is indeed directly linked with the product side of the overall reaction.

View Article and Find Full Text PDF

Aerobic oxidation of NHC-catalysed aldehyde esterifications with alcohols: benzoin, not the Breslow intermediate, undergoes oxidation.

Chem Commun (Camb)

July 2013

Centre for Synthesis and Chemical Biology, Trinity Biomedical Sciences Institute, School of Chemistry, The University of Dublin, Trinity College, Dublin 2, Ireland.

Benzoin (and neither the Breslow intermediate nor the NHC-aldehyde tetrahedral adduct) has been unambiguously identified as the oxidised species in aerobic NHC-catalysed aldehyde esterifications.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!