Hexaborylbenzene and Tetraborylethene Derivatives

Abstract

Transition metal catalyzed reactions of the diborylacetylene 1 allow access to perborylated CC multiply bonded systems. Cyclotrimerization of 1 results in the hexaborylbenzene 2. Diboration of 1 with the diborane 3 provides the tetraborylethene derivative 4. Compounds 2 and 4 react with LiMe and AlMe3 under cleavage of the boron–oxygen bonds. The dodecamethyl derivative C6(BMe2)6 forms the structurally characterized complex [C6(BMe2)6 · 2 Li2O2C6H4 · 8 NC5H5] with pyridine and Li2O2C6H4.