对于某些生物碱和相关药物的合成方法,β-酰胺基酯向β-烯氨基酯的转化是必不可少的步骤。用于这种转化的已知方法不仅是逐步的,而且以低原子效率进行。本文中,我们报道了一种直接且通用的方法,其特征在于用1,1,3,3-四甲基二硅氧烷(TMDS)进行Ir催化的β-酰胺基酯的化学选择性还原。另外,在某些脂环族β-烯胺酯的13 C NMR光谱中观察到缺少某些信号。这揭示了文献中长期存在但被忽略的现象。
Introduction of a clean and promising protocol for the synthesis of β-amino-acrylates and 1,4-benzoheterocycles: an emerging innovation
作者:Garima Choudhary、Rama Krishna Peddinti
DOI:10.1039/c1gc15701a
日期:——
A highly efficient, elegant and simple procedure with exceptionally mild conditions has been proposed for the synthesis of β-amino-acrylate derivatives and an array of biologically and pharmaceutically active benzoheterocycles. The protocol offers a valuable alternative to known methods and will find applications in the field of green synthesis. The regio- and stereo-chemistry of the products were established by IR, NMR and single crystal X-ray analysis.
An efficientsynthesis of various β-enaminoesters has been achieved via Reformatskyreaction with disubstituted formamides as novel electrophiles. The exclusive β-enaminoester E-isomers were obtained in 60–72% yield.
A facile approach to substituted acrylates by regioselective and stereoselective addition of thiols and amines to an alkynyl ester in water
作者:Nitin A. Randive、Varun Kumar、Vipin A. Nair
DOI:10.1007/s00706-010-0399-9
日期:2010.12
AbstractWater-promoted hydrothiolation and hydroamination of ethyl propiolate leading to highly regioselective and stereoselective formation of thioacrylates and β-enamino esters in excellent yields, by a simple, efficient, and environmentally friendly reaction procedure without employing any hazardous reagent or solvent is reported. Graphical Abstract
benzyl bromide 2 and cinnamyl bromide 3 give products which are dependent both upon the nature of the amine component of the enamine and, in the case of the amides, upon the amine from which the amide is derived. The β-enamino esters react with benzyl bromide to yield predominantly dialkylated products in the case of the pyrrolidine ester 1a. Reactions of the same esters with cinnamyl bromide yield
Method for the Production of Halogen-Substituted 2-(aminomethylidene)-3-oxobutyric Acid Esters
申请人:Zierke Thomas
公开号:US20110040096A1
公开(公告)日:2011-02-17
The present invention relates to a process for preparing 2-(aminomethylidene)-4,4-dihalo-3-oxobutyric esters of the formula (I),
wherein R
1
, R
2
, R
3
are C
1
-C
6
-alkyl, C
1
-C
6
-haloalkyl, C
2
-C
6
-alkenyl, C
3
-C
10
-cycloalkyl or benzyl, and/or R
2
together with R
3
and the nitrogen atom to which the two radicals are attached are a heterocyclic radical, in which a corresponding 3-aminoacrylic ester is reacted with a halogen-substituted acetyl fluoride in the presence of at least one alkali or alkaline earth metal fluoride; and the further conversion of halogen-substituted 2-(aminomethylidene)-3-oxobutyric esters of the formula (I) to halomethyl-substituted pyrazol-4-ylcarboxylic acids and their esters.