AgAsF6 as safe alternative to AgClO4 for generating cationic zirconocene species: Utilities in lewis acid-promoted selective CC bond forming reactions
synthesis, AgAsF6 proved to be an efficient catalyst that serves as a safe alternative to AgClO4. Scope and limitation is discussed on this new catalyst in the processes including (1) alkyl/alkenyl transfer reaction from organozirconocene chloride to aldehyde, (2) two- and four-carbon homologation of aldehyde, (3) dual synthetic methods of 1,3-dienes from aldehydes/ketones via 1,3-bimetallic species
The effects of in-sity trimethylsilyl chloride on the regioselectivity of the addition of α-alkoxy- and α-alkyl-substituted organocuprates to enals
作者:Russell J. Kinderman、Joyce R. McKenzie
DOI:10.1016/0022-328x(89)87349-8
日期:1989.2
The regioselectivity of the addition of α-substituted organocuprates to enals has been examined. The addition of trimethylsilylchloride to both the enal and cuprate prior to the combination of the reactants improves the regioselectivity and the isolated yield for the 1,4-addition product.
Preparation of allylic alcohols by alkene transfer from zirconium to zinc
作者:Peter Wipf、Wenjing Xu
DOI:10.1016/s0040-4039(00)77062-6
日期:1994.7
in the presence of stoichiometric amounts of commercially available dimethyl- or diethylzinc. Subsequent addition of aldehydes provides an in situ protocol for the conversion of alkynes 1 into allylicalcohols 5 in good to excellent yields.
Nucleophilic addition of alkenylzirconocene chloride [Cp2Zr(Cl)CH=CHR] to aldehyde, which is ordinarily a slow reaction, is remarkably accelerated by a catalytic amount of AgClO4. The rate acceleration effect is also valid for the alkyl congener, Cp2Zr(Cl)R.
Wipf Peter, Xu Wenjing, Tetrahedron Lett, 35 (1994) N 29, S 5197-5200