Synthesis and physico-chemical properties of new 3-benzyl-4-thioxo-5-arylideneimidazolidine-2-ones and 3-benzyl-5-arylideneimidazolidine-2,4-dione are described. These compounds were synthesized by condensation reaction from aromatic aldehydes and 3-substituted imidazolidine-2,4-diones or 4-thioxoimidazolidine-2-ones. The N-alkylation of 5-benzylideneimidazolidine-2,4-dione led simultaneously to mono-
A PEG bridged tertiary amine functionalized ionic liquid exhibiting thermoregulated reversible biphasic behavior with cyclohexane/isopropanol: synthesis and application in Knoevenagel condensation
作者:Jun Luo、Tantan Xin、Yinglei Wang
DOI:10.1039/c2nj40890b
日期:——
A novel poly(ethylene glycol) bridged tertiary amine functionalized ionic liquid PEG800-DPIL(Cl) was synthesized. It can form a temperature driven reversible biphasic system with cyclohexane/isopropanol mixed solvent. This biphasic system was applied in Knoevenagel condensation up to 99%. PEG800-DPIL(Cl) could be simply recovered and recycled for several runs.
An efficient N,N′‐dioxide–lanthanum(III) complex catalytic system has been developed for the diastereo‐ and enantioselective Michael‐initiated ring‐closure (MIRC) reaction of 2‐cyano‐3‐arylacrylates with 2‐bromomalonates. Various chiral cyclopropanes with multiple substitutions were obtained in high yields (up to 93%) with excellent dr (>95:5 dr) and good ee values (up to 91% ee). The catalytic system
Nucleophilic heterocyclic carbene as a novel catalyst for cyclopropanation of cyano acrylates
作者:Anabha E. Raveendran、Rony Rajan Paul、Eringathodi Suresh、Vijay Nair
DOI:10.1039/b916343c
日期:——
Nucleophilic heterocyclic carbenes (NHCs) have been used for the first time as catalysts in the cyclopropanation of ethyl cyanocinnamates with phenacyl bromide by Michael-initiated ring-closure (MIRC).
A novel synthesis of dibenzo[c,f]chromenes, dibenzo[c,h]chromenes and benzo[7,8]chromeno[3,4-f]isoindoles as antimicrobial agents
作者:Mohamed S.A El-Gaby、Medhat A Zahran、Magda M.F Ismail、Yousry A Ammar
DOI:10.1016/s0014-827x(00)00008-2
日期:2000.3
4-amino-5-oxo-2-aryl-5H-dibenzo[c,f]chromene-3-carbonitriles (4a,b); with ethyl 3,4-dichlorobenzylidene cyanoacetate to furnish dibenzo[c,f]chromene (5) and with elemental sulfur in dioxane containing piperidine to give thieno[3,4-d]naphtho[2,1-b]pyranone (6). Similarly, naphtho[1,2-b]pyranone (7) was reacted with arylmethylenemalononitriles and elemental sulfur to furnish dibenzo[c,h]chromenes (8) and thieno[3