Synthesis of carborane-fused carbo- and heterocycles via zirconacyclopentane intermediates.

A variety of carborane-fused carbo- and heterocycles were prepared in good to high isolated yields via the reaction of carborane-fused zirconacyclopentane with a series of substrates such as S8 , Se, Te, CO, XylNC, MeOOC-CH[double bond, length as m-dash]N2 , PhPCl2 , n Bu2 SnCl2 and Me2 GeCl2 . However, it was found that the Zr-C bond in the zirconacyclopentane did not show any reactivity towards PhBCl2 , PhCN and PhCH[double bond, length as m-dash]NPh. This approach represents a promising route to functionalized carboranes that are difficult to access by conventional methods.