PPh 3 /CCl 4 system has been employed for the stereoselective synthesis of (Z)- and ( £ )-allyl chlorides from Baylis-Hillman adducts in excellent yields.
Mapping the Mechanism of Nickel-Ferrophite Catalysed Methylation of Baylis-Hillman-Derived S<sub>N</sub>2′ Electrophiles
作者:Andrew Novak、Maria José Calhorda、Paulo Jorge Costa、Simon Woodward
DOI:10.1002/ejoc.200801029
日期:2009.2
presence of ferrophite ligands has been investigated computationally and experimentally. The sense and degree of enantioselectivity attained is independent of both the leaving group and the isomeric structure of the initial allylic halide. DFT studies support the selective formation of a limited number of energetically favoured anti and syn π-allyl intermediates. The observed regio- and enantioselectivity
A new and convenient stereoselective synthesis of (Z)-2-(chloromethyl)alk-2-enoates has been achieved from Baylis–Hillman adducts by treatment with PPh3/Cl3CCONH2 at room temperature. The synthesis can proceed under mild and acid-free conditions to form the products in high yields.
Reaction of Baylis–Hillman products with Swern and Dess–Martin oxidants
作者:Nicholas J Lawrence、J.Paul Crump、Alan T McGown、John A Hadfield
DOI:10.1016/s0040-4039(01)00587-1
日期:2001.6
The Baylis–Hillman adducts of aryl aldehydes and alkyl acrylates are efficiently oxidized to the corresponding α-methylene-β-keto esters with the Dess–Martin periodinane. The attempted Swern oxidation of the same adducts resulted in SN2′-type substitution of the allylic hydroxyl group by chloride.
芳基醛和丙烯酸烷基酯的Baylis-Hillman加合物可被Dess-Martin高碘烷有效地氧化为相应的α-亚甲基-β-酮酸酯。相同加合物的尝试的Swern氧化导致烯丙基羟基被氯化物的S N 2'型取代。
Asymmetric chemo- and regiospecific addition of organozinc reagents to Baylis–Hillman derived allylic electrophiles
作者:Christoph Börner、Paul J. Goldsmith、Simon Woodward、Josep Gimeno、Serafino Gladiali、Daniela Ramazzotti
DOI:10.1039/b006943o
日期:——
The copper-catalysed SN2â² addition of
ZnR2 to allylic
(Z)-ArCHC(CH2X)(CO2Et) (X = Br, Cl,
OSO2Me) fashions only
ArCH(R)C(CH2)(CO2Et); use of a chiral ligand
gives up to 64% ee for this demanding reaction.