A series of ruthenium hydride N-alkyl heterocyclic carbene complexes has been investigated as catalysts for a tandem oxidation/Wittig/reduction reaction to give C-C bonds from alcohols. The C-H-activated carbene complex Ru((IPr2Me2)-Pr-i)'(PPh3)(2)(CO)H (9) proves to be the most active precursor catalyzing the reaction of PhCH2OH and Ph3P=CHCN in 3 h at 70 degrees C. These results provide (a) a rare case in which N-alkyl carbenes afford higher catalytic activity than their N-aryl counterparts and (b) a novel example of the importance of NHC C-H activation in a catalytic cycle.