摘要 在此,我们报道了 Biginelli 加合物、4-(2-羟基苯基)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (I) 与氧的一锅环化反应。 -桥连加合物,乙基 2-methyl-4-thioxo-3,4,5,6-tetrahydro-2 H -2,6-methanobenzo[ g ] [1,3,5]oxadiazocine-11-carboxylate (II)使用六水合高氯酸锌 (II) 作为高效催化剂,在温和的反应条件下获得高产率和高纯度。环状产物 (II) 在固态和溶液中均使用 FT-IR、 1 H NMR 和紫外-可见光谱进行表征。使用密度泛函理论和 B3LYP/6-311++G(d,p) 水平的理论计算被用于进一步研究结构特性。DFT 计算(气相)揭示了环状化合物 II (3.45 kcal/mol)
New Ytterbium Complex-catalyzed Multicomponent Reactions for Synthesis of Dihydropyrimidines: [4+2] Cycloaddition vs. Biginelli Type Reaction
作者:Jie Zhu、Mingjie Zhang、Bo Liu、Xiaojuan Li
DOI:10.1246/cl.2009.56
日期:2009.1.5
A new schiff base ytterbium complex was synthesized and used as catalyst for a three-component, one-potreactioninvolving 1,3-keto ester with urea or thiourea and aldehyde. The reactions resulted ...
A Remarkable Rate Acceleration of the One-Pot Three-Component Cyclocondensation Reaction at Room Temperature: An Expedient Synthesis of Mitotic Kinesin Eg5 Inhibitor Monastrol
A general and practical route for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones by a one-pot condensation of aldehydes, β-ketoesters, and urea is described using trimethylsilyltriflate (1 mol%)-mediated cyclocondensation reaction at room temperature within 15 minutes. Yields are significantly higher than utilizing classical Biginelli reaction conditions. Synthesis of mitotic Kinesin Eg5 inhibitor monastrol has been achieved in 95% isolated yield.
Indium(III) bromide efficiently catalyzes the three-component coupling of beta-keto esters, aldehydes and urea (or thiourea) to afford the corresponding dihydropyrimidinones. This new protocol for the Biginelli reaction includes the following important features: produces excellent yields, allows the recycling of catalyst with no loss in its activity, and leads to zero-discharge during the process. The reaction of ethyl acetoacetate, salicylaldehyde and thiuourea produced 13-ethoxycarbonyl-9-methyl-11-thioxo-8-oxa-10,12-diazatricyclo [7.3.1.0(2,7)]-trideca-2,4-6-triene, which had its crystal structure determined by X-ray crystallography. (C) 2002 Elsevier Science Ltd. All rights reserved.