Tamed tigers: stabilization of reactive carbenes.

The behavior of tigers, and of wild cats generally, tends to be difficult to predict, let alone control. Carbenes are the chemical equivalents of wild cats, long believed to be too reactive to be isolated and handled appropriately. The reactivity of carbenes is readily appreciated by considering their electronic structure, comprising a carbon center with six electrons, four of which are involved in bonding to substituents (R and R’ in Figure 1). This electron count violates