Emerging progress in ruthenium-catalyzed transfer and asymmetric transfer hydrogenation

Ruthenium-catalysed transfer hydrogenation (TH) and asymmetric transfer hydrogenation (ATH) are well recognised as efficient and environmentally benign methods for synthesising chiral alcohols, amines, and key intermediates used in the pharmaceutical and fine chemical industries. In particular, Ru-catalysed ATH combined with dynamic kinetic resolution (DKR) allows for the stereoconvergent synthesis of complex chiral compounds from racemic carbonyl substrates with high efficiency and excellent enantioselectivity. Despite these significant advances, important challenges remain in achieving precise control over both regioselectivity and stereoselectivity of multifunctional chemical systems. Overall, this review summarises advances in TH and ATH from 2020 to 2025, focusing on catalyst design, substrate scope, mechanistic insights, and methodology development to guide the rational design of advanced ruthenium-based catalysts for the efficient synthesis of enantioenriched alcohols and complex molecules.