25354-72-7Relevant academic research and scientific papers
Minute synthesis of electrophilic alkenes under microwave irradiation
Ayoubi,Texier-Boullet,Hamelin
, p. 258 - 260 (1994)
Condensation of carbonyl derivatives 2 with active methylene compounds 1 is efficiently achieved, within 3 to 15 minutes under microwave irradiation by a solvent free reaction in the presence of carefully adjusted amounts of piperidine leading to Knocvenagel products 3 in good to excellent yields.
Efficient promiscuous Knoevenagel condensation catalyzed by papain confined in Cu3(PO4)2 nanoflowers
Yu, Jianyun,Chen, Xinxin,Jiang, Min,Wang, Anming,Yang, Linlin,Pei, Xiaolin,Zhang, Pengfei,Wu, Stephen Gang
, p. 2357 - 2364 (2018/02/06)
To develop an efficient and green immobilized biocatalyst for promiscuous catalysis which has a broad scope of applications, hybrid nanoflower (hNF) confined papain as a biocatalyst has been proposed and characterized in this study. hNFs were firstly prepared through mixing CuSO4 aqueous solution with papain in phosphate saline (PBS) at room temperature. The resulting hNFs were characterized by SEM and verified through a hydrolysis reaction with N-benzoyl-dl-arginine amide as substrate. Under optimal conditions, this nano-biocatalyst demonstrated a 15-fold hydrolytic activity compared with papain of free form, along with better thermal stability. A series of reaction factors (reaction temperature, time, and solvent) have been investigated for Knoevenagel condensation reactions with hNFs as catalyst. At optimal conditions, product yield of the hNFs catalyzed reaction was 1.3 fold higher than that of the free enzyme with benzaldehyde and acetylacetone as substrates. A few aldehydes and methylene compounds have also been used to test the generality and scope of this new enzymatic promiscuity. To sum up, the obtained hNFs demonstrate better catalytic properties than free papain and the inorganic metal-salt crystal can function as both support and promotor in biocatalysis.
Construction of Multi-Substituted Benzenes via NHC-Catalyzed Reactions of Carboxylic Esters
Wu, Jichang,Mou, Chengli,Chi, Yonggui Robin
, p. 333 - 337 (2018/03/07)
A carbene-catalyzed ester activation reaction for the synthesis of multi-substituted benzenes is developed. Tetra-substituted benzene compounds are efficiently synthesized through this methodology. Compared with aldehyde substrates used in previous reports, the ester substrates used here are much more readily available and inexpensive. In addition, the TEMPO oxidant used here is more inexpensive than the quinones commonly used in related carbene-catalyzed reactions.
Me3SiCF2Br-Self-Assisted Domino Reaction: Catalytic Synthesis of α,α-Difluorocyclopentanones from Methylvinylketones
Chang, Jian,Xu, Cong,Gao, Jie,Gao, Fengyun,Zhu, Dongsheng,Wang, Mang
supporting information, p. 1850 - 1853 (2017/04/11)
A complete self-assistance strategy based on Me3SiCF2Br was used in the domino conversion of methylvinylketones into α,α-difluorinated cyclopentanones. Initiated by 5 mol % of nBu4NBr, the multistep reaction occurred in on
The Complex Reaction of Acetohydrazides with Unsaturated Diketones: Alternative Cyclizations to 1,2-Diazepin-3-ones and Pyrazolopyridines
Alonso, Paloma,Martin-Leon, Nazario,Quinteiro, Margarita,Seoane, Carlos,Soto, Jose L.
, p. 841 - 846 (2007/10/02)
The reaction of 2-cyanoacetohydrazide (1) and 2-(ethoxycarbonyl)acetohydrazide (26) with unsaturated 1,3-diketones leading with moderate yields to 1,2-diazepinones (3, 23, 24) and pyrazolopyridines (5, 15, 20, 25) together with the corresponding acetohydrazones have been studied.The reaction course depends on the temperature and the relative reactivity of the carbonyl groups of the starting materials.When one of these carbonyl groups is less reactive (benzoyl or ethoxycarbonyl groups), the reaction does not yield diazepinones but only pyrazolopyridines and/or acetohydrazones.
