Reaction of dimethyl sulfoxide (DMSO) with 1,3,2,4-dithiastannaboretan
e 3 bearing an extremely bulky aryl group, 2,4,6-tris[bis(trimethylsil
yl)methyl]phenyl (Tbt), an the baron atom gave an oxoborane (Tbt-B=O;
4), which formed a complex with DMSO stable in solution. The formation
of the complex was confirmed by B-11 NMR and a [3+2] cycloaddition re
action with 2,4,6-tri-t-butylbenzonitrile oxide. (C) 1997 Elsevier Sci
ence Ltd.