This study developed a cost-efficient hydration/asymmetric transfer hydrogenation (ATH) process for the one-pot synthesis of valuable chiral alcohols from alkynes. During this process, the initial homogeneous cobaloxime-catalyzed hydration of alkynes was followed by heterogeneous Ru/diamine-catalyzed ATH transformation of the in-situ generated ketones, which provided varieties of chiral alcohols in good yields with up to 99% ee values. The immobilized Ru/diamine catalyst could be recycled at least three times before its deactivation in the sequential reaction system. This work shows a general method for developing one-pot asymmetric sequential catalysis towards sustainable organic synthesis.

The development of cooperative catalysis is of great significance for multi-step sequential enantioselective organic transformations. However, the complicated subtle environments and inherent mutual deactivations of chiral dual catalysts pose a great challenge in a single operation. To address these issues, we here report the rational design of an integrated Cu/bisoxazoline and Ru/diamine co-catalyst system, which enables a decarboxylative Mannich reaction/asymmetric transfer hydrogenation enantioselective cascade reaction for the direct preparation of 1,3-distereocentered β-sulfonamido alcohols. Through this cascade process, an initial Cu/bisoxazoline-catalyzed decarboxylative Mannich reaction of a cyclic aldimine and a βketo acid to afford a chiral β-sulfonamido ketone, followed by asymmetric transfer hydrogenation of this in situ generated ketone, produces a wide range of chiral β-sulfonamido alcohols in 80-95% yields with 86-99% ee and 64:36-99:1 dr. Advantageous feature of this co-catalyst system lies in the cooperative catalytic process, which greatly enhances the catalytic efficiency compared with the single-step reactions, making it attractive for gaining direct access to the diastereoselective 1,3-distereocenter.