||Mechanistic Investigation of RhI-Catalyzed Cycloisomerization of Benzylallene-Internal Alkynes via C-H Activation
Kawaguchi, Yasuaki Yasuda, Shigeo ,
Journal of Organic Chemistry
7674 , 2017-07-21 , American Chemical Society
Treatment of the benzylallene-internal alkynes with [RhCl(CO)2]2 effected a cycloisomerization via a Csp2-H bond activation to produce the tricyclo[9.4.0.03,8]pentadecapentaene skeleton. The reaction mechanism via formation of the rhodabicyclo[4.3.0] intermediates and σ-bond metathesis between the Csp2-H bond on the benzene ring and the Csp2-RhIII bond was proposed. In addition, a plausible alternative mechanism for the previously reported cycloisomerization of the benzylallene-terminal alkynes could also be proposed. © 2017 American Chemical Society.