Easy ring expansion and contraction in Pt–Sn bonded metallacycles
Abstract
The alkyne RCCR, R = CO2Me, reacts with 5-membered metallacycles [PtMe2{SnMe2ESnMe2E}(bu2bpy)], E = S, Se or Te, bu2bipy = 4,4′-di-tert-butyl-2,2′-bipyridine, yielding the corresponding 7-membered metallacycles [PtMe2{SnMe2ESnMe2CRCRE}(bu2bpy)] which slowly eliminate “Me2SnE” to give new 5-membered metallacycles [PtMe2{SnMe2CR
CRE}(bu2bpy)]; further reaction of which with excess RCCR gives [PtMe2(CR
CRH)(CCR)(bu2bpy)], a complex which contains alkyl, alkenyl and alkynyl functionalities in the same molecule.