ニッケル触媒を用いた[2+2+2]環化反応の開発とその応用

抄録

A nickel (0)-catalyzed asymmetric [2+2+2] cocyclization has been realized for the first time. This reaction involves conceptually new enantiotopic group selective formation of a nickelacyclopentadiene intermediate and produces an isoindoline derivative (73% ee, 78% conv. yield) and an isoquinoline derivative (54% ee, 62% yield) having benzylic chiral carbon centers. The synthesizing methods of biaryls using the nickel-catalyzed [2+2+2] cocyclization were also developed. Two ways for the synthesis of biaryl using [2+2+2] cocyclization were investigated: one method is that biaryls synthesized from alkyne having a phenyl group and 2 equivalents of acetylene, and the other method is that those were synthesized from α,ω-diyne having a phenyl group at the α-position and acetylene.