Specific Synthesis of 1,2- and 1,3-Dialkylidenecycloheptanes by [3+2+2] Cyclization of Alkenyl Fischer Carbene Complexes and Allenes
作者:José Barluenga、Rubén Vicente、Pablo Barrio、Luis A. López、Miguel Tomás、Javier Borge
DOI:10.1021/ja045459y
日期:2004.11.1
1,2- and 1,3-dialkylidenecycloheptane rings are specifically assembled from chromium alkenyl Fischercarbenecomplexes and allenes via [3+2+2] cyclizationreactions. The former cycloadducts are obtained when the cyclization is performed in the presence of 1 equiv of [Ni(cod)2], while the [Rh(cod)Cl]2-catalyzed cyclization leads to the latter cycloadducts.
Rhodium(I) catalyzed four-component reaction of Fischer alkenyl carbene complexes and 1,1-diphenylallene
作者:José Barluenga、Rubén Vicente、Luis A. López、Miguel Tomás
DOI:10.1016/j.tet.2005.09.093
日期:2005.11
Alkyl substituted chromium Fischer carbene complexes react with 1,1-diphenylallene in the presence of rhodium(I) catalysts (10 mol%) to yield highly substituted dienyl indenone derivatives. In this process a catalytic chromium(0)-rhodium(I) exchange occurs, four new C-C bonds are created, and four-components (two allenes, the carbene ligand and one CO ligand) are joined in a chemo- and regioselective manner. (c) 2005 Elsevier Ltd. All rights reserved.