Cyclic (Alkyl)amino Carbene Complex of Aluminum(III) in Catalytic Guanylation Reaction of Carbodiimides

Herein we report the synthesis of a cyclic (alkyl)amino carbene (cAAC) complex of AlMe3. This complex was used as an efficient catalyst for the guanylation reaction of carbodiimides with primary arylamines and secondary amines to deliver guanidine derivatives in good to excellent yields. This catalytic protocol can tolerate a wide range of functional groups. Furthermore, the longevity of the catalyst was tested in successive catalytic cycles, which indicated a sustained catalytic activity over a multiple cycles. The mechanistic pathway was well understood with the help of stoichiometric reaction and DFT study.