Synthesis of 1,2-dihydro-1,2,5-disilaborepines and 1,2-dihydro-1,2-disilafulvenes via organoboration and hydroboration/organoboration of 1,2-diethynyltetramethyldisilane

Abstract

1,2-Diethynyltetramethyldisilane (1) reacts with trimethylborane (2a) or triethylborane (2b) to give the new 1,2-dihydro-1,2,5-disilaborepines (3) in good yield; in contrast a 1,2-dihydro-1,2-disilafulvene derivative (5) is the product of the reaction between (1) and tri-isopropylborane (2c), formed by an unprecedented sequence of hydroboration and intramolecular organoboration.