A practical synthesis of novel α-dibromoalkyl- and trimethylsilylmethyl-aminoboranes and derivatives.

Addition of LDA to a mixture of trimethylborate and dibromomethane in THF at a temperature of -78°C leads to the formation of dibromomethyllithium and its capture by borate ester. ClB(OMe)(2) converts the resulting borate salt to dimethoxy(dibromomethyl)borane 2. N,N-Dimethylamino(methoxy)(dibromomethyl)borane 3 and N,N-bis(dimethylamino)(dibromomethyl)borane 4 were prepared by an amination reaction between N,N-dimethylaminotrimethylsilane and dimethoxy(dibromomethyl)borane 2.