title: Asymmetric hydrovinylation of 1-vinylcycloalkenes. Reagent control of regio- and stereoselectivity.
abstract: 1-Vinylcycloalkenes undergo highly regio- and enantioselective (>98% ee) 1,4-hydrovinylation (HV) when treated with ethylene (1 atm) at room temperature in the presence of [(S,S)-2,4-bis-diphenylphosphinopentane (BDPP)]CoCl(2) (0.05 equiv) and methylaluminoxane. The minor 1,2-HV products, seen only in 1-vinylcyclohexene (~15%) and 1-vinylcycloheptene (2%), are formed as racemic mixtures. The corresponding Ni(II)-catalyzed HV reactions of these substrates give mostly the 1,2-adducts. Racemic 4-tert-butyl-1-vinylcyclohexene, when treated with Co[(S,S)-(BDPP)]Cl(2) and ethylene, undergoes a rare enantiodivergent reaction giving two diastereomers each in >98% ee.
authors.affiliation: Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Jordan P
authors.initials: JP
authors.lastname: Page
authors.forename: T V
authors.initials: TV
authors.lastname: RajanBabu
mesh_terms: D003516:Cycloparaffins / Q000737:chemistry*; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D003516:Cycloparaffins; D014753:Vinyl Compounds