Four Ru(ii)-NC complexes were synthesized by one-step processes from the corresponding NC ligands with RuHCl(CO)(PPh3)3. These complexes were tested as catalysts for alcohol dehydrogenative reactions, and complex {(C5H4N)-(C6H4)}RuCl(CO)(PPh3)2 (1) showed the highest activity. With KOH as the nucleophile and 0.5 mol% catalyst loading, a series of carboxylic acids were synthesized in toluene without any oxidant. Catalyst 1 could be transformed to complex {(C5H4N)-(C6H4)}RuH(CO)(PPh3)2 (6) when treated with KOH and benzyl alcohol. Complex 6 further reacted with PhCHO and H2O to generate product {(C5H4N)-(C6H4)}Ru(OCOPh)(CO)(PPh3)2 (7). Complexes 6 and 7 exhibited similar efficiency to complex 1, suggesting that they can be regarded as the catalytic intermediates of 1.