Co-Catalyzed Cross-Coupling of Alkyl Halides with Tertiary Alkyl Grignard Reagents Using a 1,3-Butadiene Additive
作者:Takanori Iwasaki、Hiroaki Takagawa、Surya P. Singh、Hitoshi Kuniyasu、Nobuaki Kambe
DOI:10.1021/ja404285b
日期:2013.7.3
cobalt-catalyzed cross-coupling of alkyl (pseudo)halides with alkylGrignardreagents in the presence of 1,3-butadiene as a ligand precursor and LiI is described. Sterically congested quaternary carbon centers could be constructed by using tertiary alkylGrignardreagents. This reaction proceeds via an ionic mechanism with inversion of stereochemistry at the reacting site of the alkylhalide and is compatible with
are well tolerated. The cross-coupling of alkyl (pseudo)halides with alkyl Grignard reagents is catalyzed efficiently by a cobalt(II) chloride–lithium iodide–1,3-diene catalytic system, which provides a new synthetic tool for constructing sp3 carbon chains. This system is particularly useful for creating quaternary carbon centers via the use of tertiary alkyl Grignard reagents. Various functional groups