Asymmetric hydrovinylation of 1-vinylcycloalkenes. Reagent control of regio- and stereoselectivity.
| Autor: | Page JP; Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA., RajanBabu TV |
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| Jazyk: | angličtina |
| Zdroj: | Journal of the American Chemical Society [J Am Chem Soc] 2012 Apr 18; Vol. 134 (15), pp. 6556-9. Date of Electronic Publication: 2012 Mar 30. |
| DOI: | 10.1021/ja301640e |
| Abstrakt: | 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. (© 2012 American Chemical Society) |
| Databáze: | MEDLINE |
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