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.
Large-Scale Preparation of Polyfunctional Benzylic Zinc Reagents by Direct Insertion of Zinc Dust into Benzylic Chlorides in the Presence of Lithium Chloride
作者:Paul Knochel、Albrecht Metzger、Christian Argyo
DOI:10.1055/s-0029-1217134
日期:2010.3
prepared by the direct insertion of commercially available zinc dust into the corresponding benzylic chlorides in the presence of stoichiometric amount of lithium chloride. These polyfunctional zinc organometallics react with variouselectrophiles leading to a broad range of functionalized products. insertion - zinc organometallics - zinc - benzylic zinc chlorides - lithium chloride