Synthesis and stereochemistry of β-aryl-β-haloacroleins: useful intermediates for the preparation of (Z ) and (E )-2-en-4-ynecarbaldehydes and for the synthesis of rubrolides
作者:Damien Prim、Alexia Fuss、Gilbert Kirsch、Artur M. S. Silva
DOI:10.1039/a900286c
日期:——
The synthesis of α-substituted β-aryl-β-haloacroleins by two different pathways is presented. The determination of their stereochemistry by NOE experiments is reported for the first time. Furthermore, we describe the preparation of 2-en-4-ynecarbaldehydes and access to rubrolide derivatives from β-aryl-β-haloacroleins.
Efficient Synthesis of 4- and 5-Substituted 2-Aminopyrimidines by Coupling of β-Chlorovinyl Aldehydes and Guanidines
作者:Anna S. Komendantova、Alexander V. Komkov、Yulia A. Volkova、Igor V. Zavarzin
DOI:10.1002/ejoc.201700737
日期:2017.8.10
A general, practical and simple synthesis of functionalized 2-aminopyrimidines starting from β-chlorovinyl aldehydes and amidines is reported. In the presence of potassium carbonate, various ketones have been efficiently incorporated into the pyrimidine derivatives by two-step sequence involving the Vilsmeier-Haack reaction followed by the condensation with guanidines. The protocol is distinguished
A convenient synthesis of a series of new β-fluoroalkoxyvinyl aldehydes and their corresponding alcohols from β-chloro-α,β-unsaturated aldehydes was developed. The etherification reaction and the carbonyl reduction were successfully achieved, affording the desired products in good yields. The mechanism of the nucleophilic vinylic substitution reaction of the 3-chloro-3-phenylacrylaldehyde has been
开发了以β-氯-α,β-不饱和醛为原料方便合成一系列新型β-氟烷氧基乙烯基醛及其相应醇类的方法。成功地实现了醚化反应和羰基还原,以良好的收率提供了所需的产物。已使用 DFT 方法研究了 3-氯-3-苯基丙烯醛的亲核乙烯基取代反应的机理。IRC 分析显示存在隐藏的中间体,与一个动力学步骤两阶段过程一致。隐藏中间体Z -3-氯-3-苯基丙烯醛 (Int Z )异构化成隐藏中间体E -3-氯-3-苯基丙烯醛 (Int E) 解释为两种中间体 Int Z和 Int E之间的小能隙差异以及立体异构体E与Z相比的热力学稳定性。
Synthesis of novel β-aryl-β-(methylthio)acroleins via Vilsmeier–Haack protocol as potential 1,3-dielectrophilic three-carbon building blocks
A new general route for the synthesis of novel β-aryl-β-(methylthio)acroleins, a class of stable potential 1,3-dielectrophilic synthons, has been reported. The overall protocol involves treatment of either β-chloroacroleins or their precursor iminium salts (generated in situ from the corresponding active methylene ketones under Vilsmeier–Haack reaction conditions) with S,S-dimethyldithiocarbonates
Thermolysis of Chlorovinyl Imines as an Alternate Route for the Synthesis of Pyranoquinolin-3-one and Pyranoacridin-3-one Derivatives
作者:Prasanta Patra
DOI:10.1002/jhet.2993
日期:2017.11
2‐a]acridin‐3‐one derivatives are described by the thermolysis of suitable chlorovinyl imine derivatives. The chlorovinyl imines were obtained by condensation of suitable β‐chloro‐α,β‐unsaturated aldehydes and 6‐aminocoumarin in methanol at 15°C. Compounds showed blue fluorescence in alkaline medium.