Organic Solvent‐free Asymmetric 1,4‐Addition in Liquid‐ or Solid‐State using Conventional Stirring Catalyzed by a Chiral Rhodium Complex Developed as a Homogeneous Catalyst

Organic solvent‐free asymmetric 1,4‐addition of arylboronic acids to enone substrates was performed by using a chiral rhodium complex catalyst developed as a homogeneous catalyst. Reactions catalyzed by [RhOH(cod)] 2 with chiral diphosphine ligands in liquid‐ or solid‐state proceeded to give chiral 1,4‐adducts in high yield with enantioselectivities up to ca. 100 % ee by conventional stirring without mechanochemistry such as ball milling. The...