Organic Chemistry Section, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695 019, India.
Chem Soc Rev. 2011 Nov;40(11):5336-46. doi: 10.1039/c1cs15139h. Epub 2011 Jul 20.
Homoenolate is a reactive intermediate that possesses an anionic or nucleophilic carbon β to a carbonyl group or its synthetic equivalent. The recent discovery that homoenolates can be generated from α,β-unsaturated aldehydes via N-Heterocyclic Carbene (NHC) catalysis has led to the development of a number of new reactions. A majority of such reactions include the use of carbon-based electrophiles, such as aldehydes, imines, enones, dienones etc. resulting in the formation of a variety of annulated as well as acyclic products. The easy availability of chiral NHCs has allowed the development of very efficient enantioselective variants of these reactions also. The tolerance showed by NHCs towards magnesium and titanium based Lewis acids has been exploited in the invention of cooperative catalytic processes. This tutorial review focuses on these and other types of homoenolate reactions reported recently, and in the process, updates the previous account published in 2008 in this journal.
偕烯醇盐是一种反应性中间体，具有羰基或其合成等价物的碳β上的阴离子或亲核性。最近发现，偕烯醇盐可以通过 N-杂环卡宾（NHC）催化从α，β-不饱和醛中生成，这导致了许多新反应的发展。大多数这样的反应包括使用碳基亲电试剂，如醛、亚胺、烯酮、二烯酮等，从而形成各种稠环和非环产物。手性 NHC 的易得性允许对这些反应的非常有效的对映选择性变体进行开发。NHC 对镁和钛基路易斯酸的耐受性已被用于合作催化过程的发明中。本综述重点介绍了最近报道的这些和其他类型的偕烯醇盐反应，并在此过程中更新了 2008 年在该期刊上发表的以前的报道。
