The Aza-Cope Rearrangement in Transition Metal Complexes. Construction of an Unsaturated C₇-Ligand from Butadiyne and an Allylic Amine

Abstract

cis-RuCl2(L2)2 reacts with butadiyne in the presence of NaPF6 to give the butatrienylidene intermediate trans-[RuCl(L2)2CCCCH2]+, which can be trapped with tertiary amines to afford the ammoniobutenynyl complexes trans-[RuCl(L2)2C⋮CC(NR3) CH2]+ (L2 = dppm; R = Et, Pr). The respective N-allyl derivatives trans-[RuCl(L2)2C⋮CC((NMe2)allyl) CH2]+ (L = dppm, depe) rearrange under ambient conditions via an aza-Cope process to the amino-substituted allenylidene complexes trans-[RuCl(L2)2 CCC(NMe2)(CH2)2CHCH2]+.