Compounds such as 3, the product of a palladium[0]-catalyzed Ullmann cross-coupling of o-iodonitrobenzene and 2-iodocyclohex-2-en-1-one, undergo complementary modes of reductive cyclization depending upon the conditions employed. Thus, on treatment with hydrogen in the presence of palladium on carbon, the tetrahydrocarbazole 4 is formed, while reaction of the same substrate (3) with TiCl3 in acetone
化合物(3)是
钯[0]催化的邻
碘硝基苯和2-
碘环
己二烯-2-烯-1-酮的Ullmann交叉偶联产物,取决于所采用的条件,它们会经历互补的还原环化方式。因此,与在
钯碳的存在下氢处理,四氢
咔唑4的形成,而在同一基板(的反应3)用TiCl 4 3在
丙酮中,得到1,2,3,9-四氢-4- ħ咔-4-一6。