Manganese(III) Triacetate-Mediated Cross Coupling of Organoboron Compounds with Trichloroethylene (TCE): Synthesis of 1,1-Dichloroalkenes.

Herein, we report an efficient method for the synthesis of 1,1-dichloroalkenes from organoboron compounds. This reaction proceeds in the presence of manganese(III) triacetate using trichloroethylene (TCE) as the vinylation reagent. This reaction can tolerate various types of organoboron compounds and various functional groups. The yields are moderate to good. Surprisingly, this transformation could even be achieved in the presence of manganese(II) acetate. Furthermore, this synthetic strategy could be applied to the synthesis of 1,1,2-trichloro-, 1-chloro-, and 2-chloroalkenes.