Borane-Catalyzed, Chemoselective Reduction and Hydrofunctionalization of Enones Enabled by B–O Transborylation
Kieran Nicholson, Thomas Langer, Stephen P. Thomas
Abstract
The use of stoichiometric organoborane reductants in organic synthesis is well established. Here these reagents have been rendered catalytic through an isodesmic B-O/B-H transborylation applied in the borane-catalyzed, chemoselective alkene reduction and formal hydrofunctionalization of enones. The reaction was found to proceed by a 1,4-hydroboration of the enone and B-O/B-H transborylation with HBpin, enabling catalyst turnover. Single-turnover and isotopic labeling experiments supported the proposed mechanism of catalysis with 1,4-hydroboration and B-O/B-H transborylation as key steps.
Topics & Concepts
ChemistryBoraneCatalysisReduction (mathematics)Medicinal chemistryChemoselectivityCombinatorial chemistryStereochemistryOrganic chemistryGeometryMathematicsAsymmetric Hydrogenation and CatalysisOrganoboron and organosilicon chemistryChemical Synthesis and Analysis