INSERTION REACTIONS OF DIETHYLALUMINIUM DERIVATIVES .I. REACTION OF DIETHYLALUMINIUM ETHANETHIOLATE AND DIETHYLALUMINIUM DIMETHYLAMIDE WITH ISOCYANATES OR ISOTHIOCYANATES

Diethylaluminium ethanethiolate and dimethylamide, Et2AlX (X = SEt and NMe2), were found to react with equimolar amounts of isocyanate or isothiocyanate, RNCY (R = Me, Ph, tert-Bu, cyclohexyl; Y = O and S). The occurrence of AlS or AlN bond cleavage was confirmed by elemental analysis and by infrared and proton magnetic resonance spectra of the 1 1 adduct obtained. Infrared spectra and cryoscopic molecular weight determinations suggested the existence of an equilibrium between the monomer and a dimer formed through the bridging of heteroatoms by aluminium. Hydrolysis of the adducts gave the corresponding S-ethyl thiocarbamate and substituted urea or thiourea derivatives. Formation as by-products of allophanate derivatives and cyclic trimers of the isocyanate indicated the occurrence of successive insertion reactions. © 1969.