Rhodium-catalyzed cycloisomerization of allenenes via metalacycle intermediates
作者:Tatsuya Makino、Kenji Itoh
DOI:10.1016/s0040-4039(03)01461-8
日期:2003.8
In the presence of a catalytic amount of the rhodium complex, allenenes undergo cycloisomerization reactions to result in the selective formation of five and seven membered exo-alkylidenecarbocycles and heterocycles via novel exo-alkylidenei-hodacyclopentane intermediates. (C) 2003 Elsevier Ltd. All rights reserved.
Rhodium Complex-Catalyzed Cycloisomerization of Allenenes: Exo and Endo Cyclization Depending on the Auxiliary Ligands
作者:Tatsuya Makino、Kenji Itoh
DOI:10.1021/jo035551x
日期:2004.1.1
having an exo-alkylidene moiety. In this cycloisomerization, (E)- and (Z)-allenenes are transformed stereospecifically to the corresponding cyclic (E)- and (Z)-1,4-dienes, respectively. On the other hand, the reactions under carbon monoxide atmosphere exclusively afford seven-membered-ring products through an endo-mode cyclization. The unusual cyclization involves an allylic C−H activation process. The