Reactivity study of low-coordinate phosphaalkene IMes=PPh with Grubbs first-generation ruthenium benzylidene complexes

Reaction of IMes=PPh with RuCl2L2(CHPh) (L = PPh3 and PCy3) gave complexes with selectivity that is dependent on the metal precursor used. RuCl2(IMes=PPh)(PPh3)(CHPh), which adopts the rare cis chloride configuration, was inactive in ring-opening metathesis of diallyl sulfide. In contrast, the PCy3 analogue could not be isolated, and in fact led to an unusual decomposition product with two C-H activations.