Metal-Free Visible-Light-Mediated Desulfurization and Aromatization of Dihydropyrimidine-2-thiones for Synthesis of 2-Unsubstituted Pyrimidines
作者:Xi-Cun Wang、Zheng-Jun Quan、Tian-Yao Yang
DOI:10.1055/s-0036-1588401
日期:——
The visible-light-mediated aerobic desulfurization and aromatization of Biginelli 3,4-dihydropyrimidine-2(1H)-thiones for a one-step synthesis of 2-unsubstituted pyrimidines was established. The protocol uses molecular oxygen as an inexpensive oxidant, with visible-light irradiation, and eosin B as an organophotoredox catalyst.
建立了 Biginelli 3,4-二氢嘧啶-2(1H)-硫酮的可见光介导的有氧脱硫和芳构化,用于一步合成 2-未取代嘧啶。该协议使用分子氧作为廉价氧化剂,采用可见光照射,曙红 B 作为有机光氧化还原催化剂。
A Simple and Efficient One-Pot Synthesis of Multifunctional 5-Aryl-<i>5H</i>-thiazolo[3,2-a]pyrimidines
作者:Seerat Fatima、Anindra Sharma、Rahul Sharma、Rama P. Tripathi
DOI:10.1002/jhet.831
日期:2012.5
One‐pot economical and efficientsynthesis of multifunctional 5H‐thiazolo[3,2‐a]pyrimidines by the reaction of 4‐aryl dihydrothiopyrimidines with propargyl bromide in the presence of inorganic base has been reported in very short time.
Microwave-Assisted and Iodine-Catalyzed Synthesis of Dihydropyrimidin-2-thiones via Biginelli Reaction Under Solvent-Free Conditions
作者:Qingjian Liu、Ning Pan、Jiehua Xu、Wenwen Zhang、Fanpeng Kong
DOI:10.1080/00397911.2011.593289
日期:2013.1.1
Abstract Microwave-assistedsynthesis of 3,4-dihydropyrimidin-2-thiones via Biginelli reaction from aldehydes, acetoacetates, and thiourea in the presence of iodine undersolvent-freeconditions has been accomplished in good yields and purity without chromatographic separation. GRAPHICAL ABSTRACT
performance in multicomponent reactions (MCRs) for the one-pot synthesis of biologically useful 3,4-dihydropyrimidin-2(1H)-ones and xanthene derivatives in high to excellent yields. The eco-friendly and economic advantages of the said catalyst include its good recoverability and reusability for several runs, low price, low toxicity, and facile accessibility, manufacture, and handling.
Improving the Selectivity toward Three-Component Biginelli versus Hantzsch Reactions by Controlling the Catalyst Hydrophobic/Hydrophilic Surface Balance
作者:Babak Karimi、Akbar Mobaraki、Hamid M. Mirzaei、Daryoush Zareyee、Hojatollah Vali
DOI:10.1002/cctc.201300739
日期:2014.1
mesoporous solid acid catalysts, 3, which has a hydrophobic/hydrophobicbalance in the nanospaces (mesochannels) in which the active sites are located, is found to be a significantly more selective catalytic system in the Biginellireaction; it produces the corresponding 3,4‐dihydropyrimidin‐2‐one\thione (DHPM) 5 derivatives in good to excellent yields and excellent selectivities. Notably, in the case
两种介孔固体酸SBA-15-PrSO 3 H 1,SBA-15-Ph-PrSO 3 H 2和基于周期性介孔有机硅(PMO)的固体酸Et-PMO-Me-PrSO的催化活性和选择性在无溶剂条件下,在醛,β-酮酸酯和尿素或硫脲的环境友好的单锅三组分Biginelli反应中比较了具有不同理化表面性质的3 H 3。在这些介孔固体酸催化剂中,3,在活性位点所在的纳米空间(介孔通道)中具有疏水/疏水平衡,在Biginelli反应中被发现是选择性更高的催化系统。它可以产生相应的3,4-二氢嘧啶-2-酮\硫酮(DHPM)5衍生物,产率高,选择性好。值得注意的是,在存在1的条件下进行苯甲醛,乙酸乙酰甲酯和尿素的三组分偶联反应时,会生成Hantzsch二氢吡啶4(≈37%)和Biginelli dihydropyrimidinone 5(≈49%)的混合物,而与2相同的反应(催化剂负载量也为1 mol%)提供了