Synthesis of 1,1′‐bisphosphinoferrocenes using electrophilic addition reactions of tungsten coordinated phosphenium ions and phosphine triflates

Abstract

[W(CO)5]-coordinated phosphine triflates undergo electrophilic substitution reactions with ferrocene. We have used this methodology to add PPh2 and PPhCl units to the 1 and 1′ positions of ferrocene to form tungsten pentacarbonyl complexes of 1,1′-bisdiphenylphosphinoferrocene, 1,1′-bischlorophenylphosphinoferrocene, and 1-diphenylphosphino-1′-chlorophenylphosphinoferrocene. The chlorophenylphosphinoferrocenes can be converted to phosphine triflates, and undergo further electrophilic substitutions, allowing us to introduce additional ferrocenyl, allyl, and alkynyl groups, forming tungsten pentacarbonyl complexes of C10H8Fe(PPh2)(PPhR) and C10H8Fe(PPhR)2 (R = allyl, phenylalkynyl, ferrocenyl).