α-Hypervalent Iodine Functionalized Phosphonium and Arsonium Ylides and Their Tandem Reaction as Umpolung Reagents
作者:Zhizhen Huang、Xiaochun Yu、Xian Huang
DOI:10.1021/jo026077i
日期:2002.11.1
iodine functionalized phosphonium and arsonium ylides 2 can be used as umpolung ylides to react with nucleophiles to give alpha-heteroatom substituted ylides 4 in good yields. The nucleophilic substitution-Wittig tandem reaction of 2 can occur smoothly to provide an efficient method for the synthesis of (Z)-alpha-halo-alpha,beta-unsaturated enoates or enones 6, stereoselectively.
Versatile Transformations of α,β-Dibromoesters and Ketones in Basic Media under Microwave Irradiation
作者:Jack Hamelin、Aïcha Saoudi、Hadj Benhaoua
DOI:10.1055/s-2003-41054
日期:——
Depending on the reaction medium, α,β-dibromoesters under microwave irradiation may selectively lead to α-bromoalkenes, to alkenes or to (E)-β-bromostyrenes. The corresponding ketones give selectively the α-bromoketones.
A Highly Stereoselective Synthesis of (E)-α-Bromoacrylates
作者:Keiko Tago、Hiroshi Kogen
DOI:10.1016/s0040-4020(00)00811-5
日期:2000.11
Novel reagent, methyl bis(2,2,2-trifluoroethoxy)bromophosphonoacetate (5a), was designed and prepared in order to efficiently synthesize (E)-α-bromoacrylates 7, from which widely useful precursors for various C–C bond formations were prepared. Horner–Wadsworth–Emmons (HWE) reaction of various aldehydes with 5a in the presence of t-BuOK and 18-C-6 gave corresponding (E)-α-bromoacrylate derivatives with
A one-pot and eco-friendly synthesis of novel β-substituted-α-halomethyl acrylates and the bioactivity of these compounds in an in vitro model of mast cell degranulation induced by pro-inflammatory stimuli
作者:Maricel Martínez、María Laura Mariani、Celina García、Juan Pedro Ceñal、Alicia Beatriz Penissi