Reactions of diborane with organic isocyanates and isothiocyanates

Abstract

Methyl and phenyl isocyanates react with diborane to yield N-methyl- or N-borylformamide cyclic trimer and dimethylaminoborane or N-methylanilinoborane. The analogous isothiocyanates also react with diborane. Whereas the methylisothiocyanate-diborane reaction forms the thio analogue of the cyclic trimer obtained from the methylisocyanate–diborane reaction, the phenylisothiocyanate-diborane reaction forms the monomer PhNCS·BH₃ and the dimer (PhNCS·BH₃)₂. The identification of the compounds in the solid was by precision mass spectroscopy.