Rh(I)-Catalyzed Pauson−Khand Reaction and Cycloisomerization of Allenynes: Selective Preparation of Monocyclic, Bicyclo[<i>m</i>.3.0], and Bicyclo[5.2.0] Ring Systems
Rhodium(I)-catalyzed PKR of allenynes was found to be applicable for constructing azabicyclo[5.3.0]decadienone as well as oxabicyclo[5.3.0]decadienone frameworks. In addition, a reliable procedure for constructing a 10-monosubstituted bicyclo[5.3.0]deca-1,7-dien-9-one ring system by the rhodium(I)-catalyzed PKR of allenynes was developed under the condition of 10 atm of CO. Investigation of the rhodium(I)-catalyzed