Evidence for a ruthenium dihydride species as the active catalyst in the RuCl2(PPh3)-catalyzed hydrogen transfer reaction in the presence of base

Abstract
The role of the base in RuCl2(PPh3)3-catalyzed hydrogen transfer reactions is to generate a highly active RuH2(PPh3)3 catalyst from the dichloride via two consecutive alkoxide displacement–β-elimination sequences.