羰基化合物的α-烃基化作用是构成碳—碳键的重要反应。最常使用的传统方法是籍助强碱使羰基化合物变成烯醇盐,然后与适当的卤代烃或对甲苯磺酸酯进行S_N2反应。然而强碱性的烯醇盐使叔卤代烷及许多仲卤代烷发生消除反应,因而往往得不到预期的结果。为了解决羰基化合物的α-叔烷基化作用问题,虽然发展了其它一些方法,但有许多缺点。例如:当底物为不对称酮时,反应缺乏区域专一性,或者发生多烷基化作用,或者受到选择烷基化试剂的限制,或者反应步骤多、产率低等等。七十年代后期,陈德恒、Paterson和Reetz等人发展了一种用Lewis酸促进羰基化合物α-烃基化的方 The α-alkylation of carbonyl compounds is an important reaction to form carbon-carbon bonds. The most commonly used conventional method is to react the carbonyl compound with an enolate by means of a strong base, followed by a S_N2 reaction with a suitable halogenated hydrocarbon or p-toluenesulfonate. However, strongly basic enolates quench the tertiary alkyl halides and many of the secondary alkyl halides and often do not give the expected results. In order to solve the problem of α-tert-alkylation of carbonyl compounds, there are many disadvantages, although some other methods have been developed. For example, when the substrate is an asymmetric ketone, the reaction lacks regiospecificity, polyalkylation occurs, or is limited by the choice of alkylating agent, or there are many reaction steps and the yield is low. In the late seventies, Chen Deheng, Paterson and Reetz, who developed a Lewis acid to promote the α-alkylation of carbonyl compounds