title: Borane-mediated aldol cycloreduction of monoenone monoketones: diastereoselective formation of quaternary centers.
abstract: Exposure of monoenone monoketones to catecholborane in THF at ambient temperature results in tandem 1,4-reduction-aldol cyclization. For aromatic and heteroaromatic enones, six-membered cyclic aldol products are formed in excellent yield with high levels of syn diastereoselectivity. Five-membered ring formation proceeds less readily, but the yield of cyclized product is improved through introduction of Rh(I) salts.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Huddleston
authors.forename: David F
authors.initials: DF
authors.lastname: Cauble
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Krische
mesh_terms: D001880:Boranes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006844:Hydrocarbons, Cyclic / Q000138:chemical synthesis*; D007659:Ketones / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D012238:Rhodium / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D001880:Boranes; D006844:Hydrocarbons, Cyclic; D007659:Ketones; D012238:Rhodium