Carboamination reactions using titanium pre-catalysts:: A catalytic prospect to preparing conjugated C-N/C-C frameworks

We report in this account the synthesis of a series of titanium catalysts for the carboamination of internal aryl alkynes with aldimines to produce highly arylrated alpha,beta-unsaturated imines. Early work on the Cp2Zr(NAr) compounds have laid the premise to develop more sophisticated, but reactive, titanium reagents supported by the popular beta-diketiminates. This work has ultimately led to the preparation of simple titanium catalysts stemming from the protonation of commercially available compounds such Ti(NMe2)(4). The latter reaction offers superior carboamination catalytic activity to the earlier Zr and Ti systems and provides an interesting approach to study how C-N and C-C bonds are formed.