erythro- and threo-beta-Amino boranes Mes(2)BCHMeCHPhNHPh were synthes
ized by the reaction of Mes(2)BCHMeLi with N-benzylideneaniline. The s
tereochemistry was determined by chemical derivation into the correspo
nding cyclic carbamates via beta-amino alcohols. Their thermolysis gav
e a mixture of the corresponding (E)-enamine and its tautomer, (E)-imi
ne, in sharp contrast to that of beta-hydroxy boranes giving the olefi
ns.