title: Enantioselective synthesis of cyclobutanes via sequential Rh-catalyzed bicyclobutanation/Cu-catalyzed homoconjugate addition.
abstract: Enantiomerically enriched cyclobutanes are constructed by a three-component process in which t-butyl (E)-2-diazo-5-arylpent-4-enoates are treated with Rh2(S-NTTL)4 to provide enantiomerically enriched bicyclobutanes, which can subsequently engage in homoconjugate addition/enolate trapping sequence to give densely functionalized cyclobutanes with high diastereoselectivity. This three-component, two-catalyst procedure can be carried out in a single flask. Rh2(S-NTTL)4-catalyzed reaction of t-butyl (Z)-2-diazo-5-phenylpent-4-enoate gives the Büchner cyclization product in excellent enantioselectivity.
authors.affiliation: Brown Laboratories, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Panish
authors.forename: Srinivasa R
authors.initials: SR
authors.lastname: Chintala
authors.forename: David T
authors.initials: DT
authors.lastname: Boruta
authors.forename: Yinzhi
authors.initials: Y
authors.lastname: Fang
authors.forename: Michael T
authors.initials: MT
authors.lastname: Taylor
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Fox
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D003503:Cyclobutanes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003503:Cyclobutanes; D009942:Organometallic Compounds; D003300:Copper; D012238:Rhodium