Synthesis and Reactivity of an Unusual Ferrocenophane Bis(carbene complex)

Selective macrocyclization of 1,1'-ferrocenediylbis(amino-carbene complex) 1 was achieved by its reaction with chloro(methylene)phosphane 2 and triethylamine at ambient temperature, thus yielding the novel diaminophosphane-bridged [5]ferrocenophane bis(carbene complex) 3. This trimetallic species, which combines the structural features of both ferrocenophane and Fischer carbene complex functional groups, is prone to undergo facile ring opening under mild conditions with formation of bis(2H-azaphosphirene complexes) 6a,b and 2,3-dihydro-1,2,3-azadiphosphete complex 7. The single-crystal X-ray structures of 3 and 7 as well as the reaction courses are discussed.