Synthetic Utilization of 2-Chloro-1,1,1,2-tetrafluoroethane
摘要:
Abstractβ‐Substituted α‐fluoro‐α,β‐unsaturated carboxylic acids have been successfully synthesized, usually in a (Z)‐stereospecific manner by way of a stepwise or a one‐pot three‐step procedure starting from 2‐chloro‐1,1,1,2‐tetrafluoroethane (HCFC‐124), one of the major byproducts of the industrial process for tetrafluoroethene formation from chlorofluoromethane (HCFC‐22).
Novel O-alkyl tyrosine derivatives of low toxicity have the effect of enhancing absorption of pharmaceutically active substances such as peptides, administered by mouth or as a suppository: compounds of the invention are those of formula (I) below, esters and salts thereof wherein R¹ is a lower alkyl group optionally substituted with an alkyloxy group; X is CO or SO₂; -Y- is either a direct bond, lower alkylene group, substituted or unsubstituted vinylene group, or a group expressed as -CHR³-O- or -O-CHR³-; R² is a substituted or unsubstituted phenyl group, naphthyl group or 2-benzo-furanyl group; R³ is either hydrogen or lower alkly group; or in the formula (I). R₂-Y-X denotes N-benzyloxycarbonyl phenylalanyl, N-benzyloxycarbonyl-4-halogenophenylalanyl, or N-(m-methoxycinnamoyl) phenylalanyl group.
A novel reaction of β,β′-dihydroxy acids or esters with vanadium(V) trichloride oxide. New entry to the stereoselective synthesis of α-fluoro-α,β-unsaturated acids and esters
β,β′-Dihydroxy carboxylicacids and esters, readily prepared from dibromofluoroacetate and aldehydes, underwent deoxygenation, followed by elimination of aldehyde by the action of vanadium(V) trichloride oxide at the reflux temperature of chlorobenzene for 1 h to afford the Z isomers of α-fluoro-α,β-unsaturated acids and esters, respectively, in fair to good yields. This reaction provides a new alternative
Insight into the Reactions of Trifluorovinylsilanes with Aromatic Aldehydes
作者:Nataliia V. Kirij、Dariya A. Dontsova、Natalya V. Pavlenko、Yurii L. Yagupolskii、Harald Scherer、Wieland Tyrra、Dieter Naumann
DOI:10.1002/ejoc.200800030
日期:2008.5
s to the C=O bond of aromatic aldehydes in the presence of cesium fluoride to give the corresponding“silylated” alcohols in high yields was performed. The reactivity of the “silylated” alcohols in the presence of nucleophilicreagents and Bronsted acids was studied. On the basis of isolated compounds and of intermediates detected by NMR spectroscopic methods, several reaction pathways are proposed
An efficient synthesis of (Z)-α-fluorochalcones via the palladium-catalyzed cross-coupling reaction of (Z)-α-fluorocinnamoyl chloride with boronic acids
An efficient synthesis of α-fluorochalcones (1,3-diphenyl-2-fluoroprop-2-en-1-one) based on the Suzuki–Miyaura palladium-catalyzed cross-coupling reaction of arylboronic acids with α-fluorocinnamoyl chlorides in the presence of Cs2CO3 in toluene is described. This approach allows the synthesis of fluorinated analogues of functionalized natural chalcones.
在存在的情况下,基于铃木-宫浦钯催化的芳基硼酸与α-氟肉桂酰氯的交叉偶联反应,可高效合成α-氟代查耳酮(1,3-二苯基-2-氟代丙-2-烯-1-酮)描述了甲苯中Cs 2 CO 3的含量。这种方法可以合成功能化天然查耳酮的氟化类似物。