نتایج جستجو برای: ring opeing of epoxides

تعداد نتایج: 21176018  

2017
Hoyoung D. Park Mircea Dincă Yuriy Román-Leshkov

Despite the commercial desirability of epoxide carbonylation to β-lactones, the reliance of this process on homogeneous catalysts makes its industrial application challenging. Here we report the preparation and use of a Co(CO)4--incorporated Cr-MIL-101 (Co(CO)4⊂Cr-MIL-101, Cr-MIL-101 = Cr3O(BDC)3F, H2BDC = 1,4-benzenedicarboxylic acid) heterogeneous catalyst for the ring-expansion carbonylation...

2017
Yi Zou Marc Garcia-Borràs Mancheng C Tang Yuichiro Hirayama Dehai H Li Li Li Kenji Watanabe K N Houk Yi Tang

Epoxides are highly useful synthons and biosynthons for the construction of complex natural products during total synthesis and biosynthesis, respectively. Among enzyme-catalyzed epoxide transformations, a reaction that is notably missing, in regard to the synthetic toolbox, is cationic rearrangement that takes place under strong acid. This is a challenging transformation for enzyme catalysis, ...

Journal: :Journal of oleo science 2013
Manneganti Vijay Rachapudi Badari Narayana Prasad Bethala Lakshmi Anu Prabhavathi Devi

A convinent and efficient method was developed for the synthesis of 1,2-azidoalcohols by ring opening of terminal epoxides with sodium azide employing glycerol-based sulphonic acid functionalized carbon as heterogeneous catalyst in aqueous acetonitrile. The reaction is highly regioselective and affords the corresponding products in excellent yields (78-100%) under mild reaction conditions. The ...

Journal: :Natural product research 2006
Manuel J Cortés Veronica Armstrong Alejandro F Barrero Arnaldo E Bandoni Horacio A Priestap Alain Fournet Eric Prina

Epoxidation of argentilactone (1) with m-chloroperbenzoic acid gave a diasteromeric mixture of 2 and 3 in a ratio 1.8 : 1, with total yield 60%. The configuration of 7,8-oxirane ring for both diasteromers was determined by NMR analysis. Reaction of 1 with urea hydrogen peroxide gave the 3,4-epoxide (4) in 65% yield. The in vitro activity of 2, 3, 4 and argentilactone against Leishmania amazonen...

2014
Chuan Wang Hisashi Yamamoto

The first catalytic, highly C3-selective, stereosepecific ring-opening reaction of 2,3-epoxy alcohols and 2,3-epoxy sulfonamides has been accomplished. This process was efficiently promoted by W-salts, and the developed method was applicable to various epoxides with diverse N- and O-nucleophiles affording the products in good to excellent yields (up to 95%) and generally with high regioselectiv...

2017
Maryam MIRZA-AGHAYAN Farzaneh ALVANDI Mahdieh MOLAEE TAVANA Rabah BOUKHERROUB

Graphite oxide as a heterogeneous and recyclable solid acid catalyzed a simple and efficient method for the synthesis of β -amino alcohols by ring opening of epoxides with amines. This method is effective with various aromatic and aliphatic amines under solvent-free conditions. The corresponding β -amino alcohols are obtained in high yields (56%–95%) and short reaction times (15–30 min) with hi...

Journal: :European Journal of Organic Chemistry 2021

?-Hydroxy hydroperoxides (?-hydroperoxy alcohols) are interesting chemical platforms, notably for the preparation of 1,2,4-trioxanes, that key features numerous bioactive products such as artemisinin. In this review, main synthetic methods to prepare ?-hydroxy presented, photooxidation allylic alcohols with singlet oxygen and ring-opening epoxides H2O2. The applications also detailed, including...

Journal: :Molecules 2012
Bianca Rossi Simona Prosperini Nadia Pastori Angelo Clerici Carlo Punta

Titanium complexes have been widely used as catalysts for C‑C bond-forming processes via free-radical routes. Herein we provide an overview of some of the most significant contributions in the field, that covers the last decade, emphasizing the key role played by titanium salts in the promotion of selective reactions aimed at the synthesis of multifunctional organic compounds, including nucleop...

Journal: :The Biochemical journal 1974
F Oesch

Epoxide hydratase was solubilized from human liver microsomal fractions and purified to an extent where the specific activity was 40-fold greater than that of the liver homogenate. Combination of homogenate and purified preparation showed that the increase in activity was not due to the removal of an inhibitor. Monosubstituted oxiranes with a lipophilic substituent larger than an ethyl group (i...

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