Condition-Controlled Divergent Selective Synthesis of (Z)-N-Vinyl and N-Allenyl Benzimidazoles by Pd- or Bi-Catalyzed Direct N-Alkenylation Reactions

We have developed a condition-controlled divergent synthesis of (Z)-N-vinyl and N-allenyl benzimidazoles from 1,1,3-triphenylprop-2-yn-1-ols and benzimidazoles through Pd- or Bi-catalyzed N-alkenylation reactions involving nucleophilic attack and C–C bond cleavage processes. The desired two different kinds of products can be conveniently and selectively synthesized by using this strategy, which features stereospecific synthesis, good functional group tolerance, a broad substrate scope, and high efficiency. The strategy provides significant advantages for the synthesis of biologically and pharmaceutically active imidazoheterocycles.