title: Domino reaction involving the Bestmann-Ohira reagent and α,β-unsaturated aldehydes: efficient synthesis of functionalized pyrazoles.
abstract: A mild, efficient and rapid domino reaction involving the Bestmann-Ohira reagent (BOR) and α,β-unsaturated aldehydes has been developed for the synthesis of densely functionalized vinylpyrazoles. This reaction demonstrates the dual reactivity of BOR as a homologation reagent as well as a cycloaddition partner, thus constituting a domino reaction in an operationally simple procedure. The application of this efficient synthesis of pyrazoles has been demonstrated for the synthesis of phosphonyl analogues of pyrrolopyrazole alkaloids.
authors.affiliation: Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram extension, Sitapur Road, P.O. Box 173, Lucknow 226031, India. kishor.mohanan@cdri.res.in.
authors.forename: Shakir
authors.initials: S
authors.lastname: Ahamad
authors.forename: Ashis Kumar
authors.initials: AK
authors.lastname: Gupta
authors.forename: Ruchir
authors.initials: R
authors.lastname: Kant
authors.forename: Kishor
authors.initials: K
authors.lastname: Mohanan
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D061565:Cycloaddition Reaction; D063065:Organophosphonates / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D063065:Organophosphonates; D011720:Pyrazoles