Cooperation of Transition Metals and Chiral Brønsted Acids in Asymmetric Catalysis

Enantiodivergent Synthesis of Chiral Tetrahydroquinoline Derivatives via Ir-Catalyzed Asymmetric Hydrogenation: Solvent-Dependent Enantioselective Control and Mechanistic Investigations

“…Moreover, until now, there is no example involving the enantiodivergent synthesis of chiral tetrahydroquinolines through the same transition-metal complex catalysis. Considering the great importance of noncovalent interactions and the continuous research on the chiral bifunctional ferrocene-based bisphosphine–thiourea system, , we envision that the noncovalent anion-binding interaction between the chiral bisphosphine-thiourea ligand and the aryl-substituted quinoline substrates could be achieved by the introduction of Brønsted acid, which can activate the quinoline ring, resulting in the great improvement of reactivity and stereoselectivity control. Considering the solvent effect on the noncovalent secondary interaction, we believe that the solvent alternation could provide the possibility to realize enantiodivergent synthesis, especially the variation from an aprotic solvent to a protic solvent.…”

One-Pot Catalysis Using a Chiral Iridium Complex/Brønsted Base: Catalytic Asymmetric Synthesis of Catalponol

“…The development of enantioselective one-pot processes that enable many reactions to proceed in a single flask is now mainstream in modern organic synthesis . A one-pot strategy avoids the time, labor, and yield losses incurred during the isolation and purification of synthetic intermediates in multistep sequences.…”