FURTHER APPLICATIONS OF THE NCO- INSERTION INTO A C-SR BOND - SYNTHESIS OF THE BIS(MU-ACYLISOCYANIDE) COMPLEX [FE2(CO)2(CP)2(MU-CNC(O)SME)2]

The complex [Fe2(CO)2(CP)2(mu-CS)(mu-CSMe)]SO3CF3 (1) reacts with NnBu 4NCO to give [Fe2(CO)2(Cp)2(mu-CS){mu-CNC(O)SMe}] (2). This reaction h as been carried out separately for both the cis and trans isomers of 1 . Complex cis-2 undergoes S-methylation with MeOSO2CF3 affording the n ovel thiocarbyne derivative [Fe2(CO)2(CP)2(mu-CSMe)(mu-CNC(O)SMe)]S03C F3 (3), into which in turn an additional NCO- anion inserts to yield t he bis(mu-acylisocyanide) complex [Fe 2(CO)2(CP)2{mu-CNC(O)SMe}2] (4). All the reactions described are stereospecific and the derivatives 2- 4 do not exhibit cis-trans isomerization.