Syn- Aminoauration versus Anti- Aminoauration of Alkynes in Au(I)/Au(III) Catalysis: Understanding the Origin of Selectivity.

There is no experimental evidence of whether such gold-catalyzed aminoauration reactions follow the anti - and/or syn -pathway, and hence, to understand the origin of the selectivity in Au(I)- and Au(III)-catalyzed reactions of alkynes, a thorough mechanistic study was performed using DFT methods. The NBO and ASM analyses provided significant information about the structure-stability-reactivity of the pathway-determining states (PDS). This study further reveals that the oxidation states and geometries of gold, the steric bulk, and the dihedral angles of the PDS direct the mechanistic pathways and control the turnover frequency.