Stereoselective Halo-Succinimide Facilitated α-Halogenations of Substituted α-Trialkylsilyl-β-Substituted-α,β-Unsaturated Esters
作者:Kristina C. Probasco、Michael P. Jennings
DOI:10.1021/acs.joc.1c00876
日期:2021.7.2
halogenation of a series of (E)-α-trimethylsilyl-β-alkyl(aryl)-α,β-unsaturated esters in dimethylformamide (DMF) has furnished (Z)-β-substituted-α-halogenated-α,β-unsaturated ester products in moderate to high isolated yields (58–90%) with dr values of >20:1 coupled with the inversion of olefin stereochemistry. The reaction process was hypothesized to include an initial halonium cation intermediate,
NXS (X = Cl, Br) 介导的一系列 ( E )-α-三甲基甲硅烷基-β-烷基(芳基)-α,β-不饱和酯在二甲基甲酰胺 (DMF) 中的卤化提供了 ( Z )-β-取代-α-卤代-α,β-不饱和酯产物的分离产率中等至高(58-90%),dr 值大于 20:1,并伴有烯烃立体化学的反转。假设反应过程包括最初的卤阳离子中间体,然后是区域选择性的 DMF 开环。随后的抗-E2-型伴随消除允许产物乙烯基溴和氯酯的立体选择性形成。
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
Stereoselective Preparation of (<i>E</i>)-α-Bromoacrylates from Mixtures of Brominated Ando Phosphonates
作者:Reinhard Brückner、Thomas Olpp
DOI:10.1055/s-2004-831166
日期:——
We prepared 69:31-11:89 mixtures of phosphonates 6b and 7b containing two phenoxy substituents, a CO 2 Et group, and 1 or 2 bromine atoms, respectively, at the interspersed methylene group. Deprotonating 64:36 mixtures of these reagents with NaH and adding a variety of aldehydes at 0 °C provided unsaturated α-bromoesters. Yields were typically 70-99% and E-selectivities (i.e. ester and β-substituent
我们制备了 69:31-11:89 的膦酸酯 6b 和 7b 混合物,在散布的亚甲基上分别含有两个苯氧基取代基、一个 CO 2 Et 基团和 1 个或 2 个溴原子。将这些试剂与 NaH 的 64:36 混合物去质子化,并在 0 °C 下添加各种醛,得到不饱和的 α-溴酯。产率通常为 70-99%,E-选择性(即酯和 β-取代基顺式)为 80:20-98:2。类似地,我们通过氯化膦酸酯 49 进行到 E:Z = 94:6 (80%) 的不饱和 α-氯代酯 51。
Substituted arylcyclopropylacetamides as glucokinase activators
申请人:Weichert Gerhard Andreas
公开号:US20060111353A1
公开(公告)日:2006-05-25
According to the present invention there is provided a compounds of formula (I): and pharmaceutically acceptable salts thereof.
根据本发明,提供了式(I)的化合物及其药学上可接受的盐。
SUBSTITUTED ARYLCYCLOPROPYLACETAMIDES AS GLUCOKINASE ACTIVATORS