NEW HETEROCYCLES FROM THE REACTION OF AZONIABORATACYCLOPROPANE WITH ISOCYANIDES

The azoniaboratacyclopropane (CF3)(2)B-NMe(2)-CHSiMe(3) (I) combines i n a 1:1 fashion with isocyanides RNC (R = R' = p-MeC(6)H(4)SO(2)CH(2) and R = R'' = PhCH(2)) to give azoniaboratacyclobutane derivatives (CF 3)(2)B-C(NR)-NMe(2)-CHSiMe(3) (R = R' (II), R = R'' (III)). However, I reacts with two equivalents of tert-butyl isocyanide to form a novel diaza-azoniaboratabicyclo[3.3.0]octene (IV). The crystal structures of II and IV have been determined by X-ray methods.