Cobalt-Catalyzed Regioselective Dehydrohalogenation of Alkyl Halides with Dimethylphenylsilylmethylmagnesium Chloride

摘要

A base-mediated dehydrohalogenation reaction is among the most basic organic reactions. However, regio- and stereochemical control of the reaction are not easy, as clearly demonstrated in the historical study by Bartsch. For instance, treatment of 2-bromododecane (1a) with potassium tert-butoxide in tert-butyl alcohol for 1 d afforded a mixture of 1-dodecene (2a), (E)-2-dodecene [(E)-3a], and (Z)-2-dodecene [(Z)-3a] (eq 1). There are some studies aiming at selective dehydrohalogenation reactions, which failed to attain high selectivity or lacked generality. Development of regio- and stereoselective dehydrohalogenation that is applicable to modern organic synthesis has been awaited.