硬币的另一面:非经典格氏反应

The Other Side of Coin:Non-Classical Grignard Reaction

格氏反应是有机合成化学中最重要的碳碳键形成反应之一,是制备醇类化合物的工具反应。当格氏加成反应速率因羰基或(和)格氏试剂的立体电子效应影响而大大降低时,其他反应过程如烯醇化、还原、取代反应等会占据主导地位,目前对这些非经典的格氏反应鲜有系统性介绍。结合笔者近年来在有机合成化学方面的教学和科研工作,对非经典的格氏反应进行了梳理和归纳,并从反应机理角度对这类反应的发生进行了说明和阐释。

Grignard reaction,one of the most important carbon-carbon bond formation reactions in organic synthesis,represents an important tool for the synthesis of alcoholic compounds.When the rate of a Grignard reaction is greatly reduced due to the stereo-or electronic effect of the carbonyl group or(and)the Grignard reagent,other reaction processes such as enolization,reduction,substitution reaction,etc.may proceed dominantly.However,there is scarcely a systematic introduction on these unusual Grignard reactions.Based on the teaching and research experience of the authors in synthetic organic chemistry,this paper presents a comprehensive introduction on some non-classical Grignard reactions with emphasis on explaining and elucidating the mechanisms of these reactions.