Enantioselective intramolecular C-H amination of aliphatic azides by dual ruthenium and phosphine catalysis.

摘要: The catalytic enantioselective intramolecular C(sp3)-H amination of aliphatic azides represents an efficient method for constructing chiral saturated cyclic amines which constitute a prominent structural motif in bioactive compounds. We report dual system involving chiral-at-metal bis(pyridyl-NHC) ruthenium complex and tris(4-fluorophenyl)phosphine (both 1 mol%), facilitates the cyclization to α-aryl pyrrolidines with enantioselectivities up 99% ee, including pyrrolidine can be converted anti-tumor alkaloid (R)-(+)-crispine. Mechanistically, phosphine activates organic azide form intermediate iminophosphorane transfers nitrene unit providing imido engages highly stereocontrolled C–H amination. This catalysis combines Staudinger reaction provides novel strategy catalyzing aminations unactivated azides.