The frustrated Lewis pair induced formation of a pentafulvene [6+4] cycloaddition product

The frustrated Lewis pair Mes(2)P-CH(2)CH(2)-B(C(6)F(5))(2) reacts with excess 6,6-dimethylpentafulvene to yield a P/B-Lewis pair addition product to an elusive pentafulvene [6 + 4] cycloaddition dimer. This observation may open a new field of utilization of frustrated Lewis pair chemistry.