Synthesis of novel allene-coordinated, phosphido-bridged Ru2Pt clusters involving enyne to allene transformation

Abstract

Microwave irradiation of a toluene solution of the diyne FcC 2C2Ph and Ru3(CO)12 yields the [Ru(CO)3(η4-ruthenole)] derivatives 1a-f, which differ in relative positions of the uncoordinated alkyne group. Upon treatment with Pt(PPh3)2C2H4, the ruthenoles 1a-c, containing a single free C-C unit at the α position with respect to the ring Ru metal, yield the novel allene-coordinated, phosphido-bridged Ru 2Pt clusters 3a-c along with their phosphine-substituted derivatives 4a-c. Under similar reaction conditions, isomers 1d,e, which are devoid of any free C-C unit at the α position, and 1f, having free C-C units at both α positions, form only their phosphine-substituted derivatives 4d-f. The formation of Ru2Pt clusters from ruthenole complexes involves cleavage of the P-C bond of the phosphine and migration of the resulting phenyl group onto the free alkyne, which leads to enyne to allene transformation. © 2014 American Chemical Society.