Rh-Catalyzed Enantioselective Diboration of Simple Alkenes:  Reaction Development and Substrate Scope

• Published in: Journal of organic chemistry Vol. 70; no. 23; pp. 9538 - 9544
• Main Authors: Trudeau, Stéphane, Morgan, Jeremy B, Shrestha, Mohanish, Morken, James P
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 11.11.2005; Amer Chemical Soc
• Subjects: Alkenes - chemistry; Boron Compounds - chemistry; Catalysis; Chemistry; Chemistry, Organic; Exact sciences and technology; Kinetics and mechanisms; Ligands; Molecular Structure; Organic chemistry; Oxidation-Reduction; Physical Sciences; Reactivity and mechanisms; Rhodium - chemistry; Science & Technology; Stereoisomerism; GENERAL-SYNTHESIS; MOLECULAR-STRUCTURES; CHIRAL SYNTHESIS; BORONIC ESTERS; OXIDATIVE ADDITION; PLATINUM-CATALYZED DIBORATION; RHODIUM COMPLEXES; ASYMMETRIC HYDROBORATION; HOMOLOGATION; ORGANOBORANES; Diol; Rhodium complex; Catalytic reaction; Transition element complexes; Enantioselectivity; Ligand; Boration; Selectivity; Diborane; Organic boronate; Reaction mechanism; Boron Organic compounds; Oxidation; Ethylenic compound
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo051651m

The rhodium-catalyzed reaction between bis(catecholato)diboron and simple alkenes results in the syn addition of the diboron across the alkene. The resulting 1,2-bis(boronate) is subsequently oxidized to provide the 1,2-diol. In the presence of enantiomerically enriched Quinap ligand, high enantioselection in the diboration can be achieved. The reaction is highly selective for trans- and trisubstituted alkenes and can be selective for some monosubstituted alkenes as well. The development of this reaction is described as is the substrate scope and experiments that are informative about the reaction mechanism and competing pathways.