Reusable Gold(I) Catalysts with Unique Regioselectivity for Intermolecular Hydroamination of Alkynes

Abstract

AbstractTwo gold(I) phosphine complexes bearing the low‐coordinating bis(trifluoromethanesulfonyl)imidate ligand, namely AuSPhosNTf2 and AuPPh3NTf2, are active catalysts for the regioselective intermolecular hydroamination of both internal and terminal alkynes under mild reaction conditions. The catalysts show a regioselectivity based on electronic rather than steric factors, which allow the preferential synthesis of regioisomers opposite to those described previously. This subtle chemo‐ and regioselectivity depends on the catalyst, substrates and reaction conditions employed, and allows one to perform new tandem reactions. These gold(I) complexes operate under free‐solvent conditions, without exclusion of air, without addition of acidic promoters and can be quantitatively recovered and reused by simple precipitation in hexane.