Silica-immobilized chiral dirhodium(II) catalyst for enantioselective carbenoid reactions.Org Lett. 2013 Dec 20; 15(24):6136-9.OL
A silica-supported dirhodium(II) tetraprolinate catalyst was synthesized in four steps from l-proline and used in a range of enantioselective transformations of donor/acceptor carbenoids. These include cyclopropenation, cyclopropanation, tandem ylide formation/[2,3] sigmatropic rearrangement, and a variety of combined C-H functionalization/Cope rearrangement reactions. The products of these transformations were obtained in yields and levels of enantioselectivity comparable to those obtained with its homogeneous counterpart, Rh2(S-DOSP)4. The silica-supported Rh2(S-DOSP)4 derivative was successfully recycled over five reactions.