Preparation and crystal structures of a bidentate isocyanide and its tetracarbonylchromium complex

Abstract

The bidentate diisocyanide ligand 2,2′-(methylendioxy)diphenylisocyanide 4 was prepared by Williamson coupling of 2 with dichloromethane, reduction of the nitro functions and conversion ofthe primary amine groups into isocyanide function Ugi synthesis. The novel ligand 4 reacts with [M(nor)(CO) 4] (nor = norbornadiene) to yield the complexes [M( 4)(CO) 4] ( M = Cr, 5; M = Mo, 6 ) which possess 12-membered chelate rings, the smallest rings observed so far for chelating isocyanide ligands. Compounds 4 and 5 were characterized by X-ray crystallography.