51477-11-3Relevant articles and documents
Asymmetric epoxidation of α,β-unsaturated ketones via an amine-thiourea dual activation catalysis
Zhang, Lu-Wen,Wang, Li,Ji, Nan,Dai, Si-Yang,He, Wei
supporting information, (2021/03/15)
A simple asymmetric epoxidation method is developed to effectively synthesize chiral α-carbonyl epoxides through an amine-thiourea dual activation catalysis. In this method, TBHP, as an oxidant, determined the reaction rate, and the chiral amine-thiourea catalyst effectively controlled the stereoselectivity of the reaction, and KOH promoted deprotonation. 22 examples of α,β-unsaturated ketones with various substituent groups are smoothly converted into α-carbonyl epoxides with moderate to excellent enantiomeric excess.
Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Using Amide-Based Cinchona Alkaloids as Hybrid Phase-Transfer Catalysts
Jurczak, Janusz,Majdecki, Maciej,Tyszka-Gumkowska, Agata
supporting information, (2020/11/13)
A series of 20 one chiral epoxides were obtained with excellent yields (up to 99%) and enantioselectivities (up to >99% ee) using hybrid amide-based Cinchona alkaloids. Our method is characterized by low catalyst loading (0.5 mol %) and short reaction times. Moreover, the epoxidation process can be carried out in 10 cycles, without further catalyst addition to the reaction mixture. This methodology significantly enhance the scale of the process using very low catalyst loading.
Visible-Light-Driven Epoxyacylation and Hydroacylation of Olefins Using Methylene Blue/Persulfate System in Water
De Souza, Gabriela F. P.,Bonacin, Juliano A.,Salles, Airton G.
, p. 8331 - 8340 (2018/07/21)
A visible-light-driven strategy for hydroacylation and epoxyacylation of olefins in water using methylene blue as photoredox catalyst and persulfate as oxidant is reported. In this unprecedented unified approach, two different transformations are accomplished using only one set of reagents. The method has a broad scope spanning a range of aromatic and aliphatic aldehydes as well as conjugated and nonconjugated olefins to deliver ketones and epoxyketones from abundant and inexpensive chemical feedstocks.
Biomimetic hydrogenation: A reusable NADH co-enzyme model for hydrogenation of α,β-epoxy ketones and 1,2-diketones
Huang, Qiang,Wu, Ji-Wei,Xu, Hua-Jian
, p. 3877 - 3881 (2013/07/05)
A biomimetic method has been developed to transform α,β-epoxy ketones or 1,2-diketones into corresponding β-hydroxy ketones or α-hydroxy ketones using a catalytic amount of BNAH or BNA +Br-. The regeneration of BNAH or BNA+Br - is achieved by a mixture of HCOOH/Et3N. A radical mechanism is proposed to explain these observations.
PAA-supported Hantzsch 1,4-dihydropyridine ester: An efficient catalyst for the hydrogenation of α,β-epoxy ketones
Zhou, Xin-Feng,Wang, Peng-Fei,Geng, Ye,Xu, Hua-Jian
, p. 5374 - 5377 (2013/09/12)
A new type of water-soluble polymer-supported NADH co-enzyme model-PAA (polyacrylic acid)-supported Hantzsch 1,4-dihydropyridine ester (PAA-HEH) was designed and synthesized. Catalytic amount of the supported reagent was used in the hydrogenation of α,β-epoxy ketones to the corresponding β-hydroxy ketones and showed great catalytic efficiency in the reduction reaction. This PAA-HEH was an optimal potential for recycling use.
Study on comparison of reducing ability of three organic hydride compounds
Feng, Yi-Si,Yang, Chun-Yan,Huang, Qiang,Xu, Hua-Jian
body text, p. 5053 - 5059 (2012/07/28)
Selective reduction of three kinds of substrates were studied to evaluate the reducing abilities of N,N-dimethyl-benzimidazolidine (DMBI), 2-phenylbenzimidazoline (PBI) and 2-phenylbenzothiazoline (PBT). As hydride donors, these three five-membered heterocyclic compounds performed different reducing abilities depending on the substrates.
Trichloroisocyanuric acid: A convenient oxidation reagent for phase-transfer catalytic epoxidation of enones under non-aqueous conditions
Ye, Jinxing,Wang, Yongcan,Chen, Jiping,Liang, Xinmiao
, p. 691 - 696 (2007/10/03)
Trichloroisocyanuric acid (TCCA) is a cheap, safe and readily available alternative to the commonly used hydrogen peroxide and hypochlorite for the phase-transfer catalytic epoxidation of α,β-enones under non-aqueous conditions. A variety of chalcone derivatives give the corresponding epoxides with quantitative conversion and satisfactory yields in just a few hours under mild conditions. An asymmetric variant of the epoxidation can be carried out in the presence of chiral N-anthracenylmethylcinchonidine bromide catalyst giving 73-93% ees and 76-94% yields.