Pyridylseleno group in organic synthesis. Preparation and oxidation of .alpha.-(2-pyridylseleno) carbonyl compounds leading to .alpha.,.beta.-unsaturated ketones and aldehydes
Routes to 4-substituted analogues of the glycine/NMDA antagonist HA-996. Enantioselective synthesis of (3R,4R) 3-amino-1-hydroxy-4-methyl-2-pyrrolidinone (L-687, 414).
摘要:
Glycine anion (4) and glycine cation (8) synthons are used in efficient syntheses of 4-substituted analogues of HA-966 (1). A stereospecific route to cis derivatives involves hydrogenation of examines such as 16. Introduction of a chiral auxiliary leads to an enantioselective synthesis of 2a (L-687,414).
Indium-catalyzed coupling reaction between silyl enolates and alkyl chlorides or alkyl ethers
作者:Yoshihiro Nishimoto、Takahiro Saito、Makoto Yasuda、Akio Baba
DOI:10.1016/j.tet.2009.03.106
日期:2009.7
The coupling reactions of alkyl chlorides with silyl enolates catalyzed by InBr3, and the coupling reactions of alkylethers with silyl enolates catalyzed by the combined Lewis acid of InBr3/Me3SiBr are described. In both reaction systems, various types of silyl enolates were used to give corresponding α-alkylated esters, ketones, carboxylic acids, amides, thioesters, and aldehydes.
描述了烷基氯化物与InBr 3催化的烯醇硅酸酯的偶联反应,以及烷基醚与InBr 3 / Me 3 SiBr的路易斯酸催化的烯醇硅酸酯的偶联反应。在两个反应系统中,都使用了各种类型的甲硅烷基烯酸酯,以生成相应的α-烷基化的酯,酮,羧酸,酰胺,硫代酯和醛。
Sur l'obtention hautement regio-et stereoselective d'enoxysilanes par action du bis(trimethylsilyl) acetamide en milieu hmpt sur les derives carbonyles enolisables
作者:James Dedier、Pierre Gerval、Emile Frainnet
DOI:10.1016/s0022-328x(00)85896-9
日期:1980.2
The authors describe a new and general method for the preparation of enoxysilanes by silylation of enolizable aldehydes and ketones by use of bis(trimethylsilyl) acetamide in HMPT, in the presence of very small quantities of sodium metal(or another basic agent) as catalyst. This method was found to proceed rapidly, with good yields, and is highly regio-and stereo-selective (giving the Z isomer, orientation
Eine flexible Synthese von 4-Oxobutansäure- methylestern und deren Derivaten
作者:Thomas Kunz、Agnes Janowitz、Hans-Ulrich Reißig
DOI:10.1055/s-1990-26783
日期:——
A Flexible Synthesis of Methyl 4-Oxobutanoates and Their Derivatives Ring cleavage of several methyl 2-trimethylsiloxycyclopropanecarboxylates 3 provides rather sensitive methyl 4-oxobutanoates (ß-formyl esters) 4 in excellent yields. Siloxycyclopropanes 3 are easily available either directly from the corresponding silyl enol ethers 2 and methyl diazoacetate or by alkylation of deprotonated cyclopropanes 3. A highly efficient one-pot procedure affords methyl 4,4-dimethoxybutanoates 5, which can be converted into protected 4-hydroxybutanals 7 and 8 by standard methods.
Crossed aldolreactionbetween aromatic aldehydes having an electron-withdrawing group and trimethylsilylenolates generated from several aldehydes proceeded smoothly in dry or water-containing DMF...
Coupling Reaction of Alkyl Chlorides with Silyl Enolates Catalyzed by Indium Trihalide
作者:Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1021/ol701684n
日期:2007.11.1
Indium(III) halide catalyzed not only the coupling of alkyl chlorides with silyl enolates derived from esters, ketones, and aldehydes to give a variety of alpha-alkylated carbonylcompounds but also one-pot, three-component reactions of aldehyde enolate, alkyl chloride, and allylsilane or alkynylsilane.