From borane to metal-bound boraindene: a cascade of bond breaking and making at rhodium

Abstract

Few monobenzannulated 1-boraindene compounds have been reported. Here we report the synthesis of two 1-boraindenes, accessed by a bond-breaking and -making cascade from a secondary borane and diolefin, mediated by a simple pentamethylcyclopentadienyl-ligated rhodium(I) complex, [(Cp*)Rh(η²,η²-NBD)] (Cp* = C₅Me₅⁻, NBD = norbornadiene).