Nucleophilic Acylation of o-Quinone Methides: An Umpolung Strategy for the Synthesis of α-Aryl Ketones and Benzofurans
摘要:
The synthesis of alpha-aryl ketones is accomplished by the direct nucleophilic acylation of o-quinone methide electrophiles. In this process, two reactive intermediates, carbonyl anions and o-quinone methides, are generated in one flask upon treatment of the corresponding thiazolium carbinols and silyl protected phenols with a soluble fluoride source. These intermediates then undergo productive addition reactions to afford the desired alpha-aryl ketone adducts. This new strategy has been applied to a short synthesis of the natural product demethylmoracin I.
7-MEMBERED FUSED HETEROCYCLES AND METHODS OF THEIR SYNTHESIS
申请人:Northwestern University
公开号:US20150065703A1
公开(公告)日:2015-03-05
Disclosed are a new method for synthesizing 7-membered fused heterocycles and compounds synthesized by the new method. The method involves a dual activation strategy using an N-heterocyclic carbene catalyst as a first Lewis base and another second Lewis base. Compounds synthesized by the disclosed method may include new benzoxopinone compounds, as well as benzoxepane compounds and benzoazepinone compounds that optionally may be derived from the disclosed benzoxopinone compounds.
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
作者:Javier Izquierdo、Ane Orue、Karl A. Scheidt
DOI:10.1021/ja405833m
日期:2013.7.24
activation strategy integrating N-heterocycliccarbene (NHC) catalysis and a second Lewis base has been developed. NHC-bound homoenolate equivalents derived from α,β-unsaturated aldehydes combine with transient reactive o-quinone methides in an enantioselective formal [4 + 3] fashion to access 2-benzoxopinones. The overall approach provides a general blueprint for the integration of carbenecatalysis with