Formation of Oxoborane and Thioxoborane from a Dithiastannaboretane Derivative

Reaction with, an oxygen-donating reagent such as DMSO and thermolysis of a 1,3,2,4-dithiastannaboretane derivative bearing 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt) group led to the formation of novel boron–group 16 element double bond compounds, oxoborane (Tbt–B=0) and thioxoborane (Tbt–B=S). The oxoborane and thioxoborane underwent cycloaddition reactions to give the corresponding adducts in good yields.