Fiber-supported Fe(iii) complex catalyst in spinning basket reactor for cleaner ring-opening of epoxides with alcohols

2019 ◽  
Vol 21 (13) ◽  
pp. 3573-3582 ◽  
Author(s):  
Xian-Lei Shi ◽  
Benyu Sun ◽  
Qianqian Hu ◽  
Yongju Chen ◽  
Peigao Duan
Keyword(s):  
Ring Opening ◽  
Complex Catalyst ◽  
Ring Opening Reactions ◽  
Ring Opening Of Epoxides

An available, nontoxic, efficient, recyclable and gram-scaleable fiber-supported Fe(iii) complex catalyst in spinning basket reactor for cleaner ring-opening reactions.

Enantioselective formation and ring-opening of epoxides catalysed by halohydrin dehalogenases

2006 ◽  
Vol 34 (2) ◽  
pp. 291-295 ◽  
Author(s):  
D.B. Janssen ◽  
M. Majerić-Elenkov ◽  
G. Hasnaoui ◽  
B. Hauer ◽  
J.H. Lutje Spelberg
Keyword(s):  
Ring Opening ◽  
Building Blocks ◽  
Epoxide Ring ◽  
Structural Studies ◽  
Halide Ions ◽  
Catalytic Promiscuity ◽  
Agrobacterium Radiobacter ◽  
Enzymatic Production ◽  
Ring Opening Reactions ◽  
Ring Opening Of Epoxides

Halohydrin dehalogenases catalyse the conversion of vicinal halohydrins into their corresponding epoxides, while releasing halide ions. They can be found in several bacteria that use halogenated alcohols or compounds that are degraded via halohydrins as a carbon source for growth. Biochemical and structural studies have shown that halohydrin dehalogenases are evolutionarily and mechanistically related to enzymes of the SDR (short-chain dehydrogenase/reductase) superfamily. In the reverse reaction, which is epoxide-ring opening, different nucleophiles can be accepted, including azide, nitrite and cyanide. This remarkable catalytic promiscuity allows the enzymatic production of a broad range of β-substituted alcohols from epoxides. In these oxirane-ring-opening reactions, the halohydrin dehalogenase from Agrobacterium radiobacter displays high enantioselectivity, making it possible to use the enzyme for the preparation of enantiopure building blocks for fine chemicals.

Electrophilic Ring Opening of Small Heterocycles

Synthesis ◽  
2017 ◽  
Vol 49 (24) ◽  
pp. 5307-5319 ◽  
Author(s):  
Chuan Wang
Keyword(s):  
Ethylene Oxide ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Ring Opening ◽  
Building Blocks ◽  
Nickel Titanium ◽  
Ring Opening Reactions ◽  
Palladium Catalyzed ◽  
Ring Opening Of Epoxides ◽  
Nucleophilic Ring Opening

Small heterocycles, such as epoxides, aziridines, and ox­etanes are among the most useful building blocks in organic synthesis. Through electrophilic ring opening of these molecules, various electrophilic functional groups can be installed, which cannot be achieved via classic nucleophilic ring-opening reactions. In this review, the developments of electrophilic ring opening of small heterocycles are surveyed and organized according to the types of metal promoters.1 Introduction2 Electrophilic Ring Opening of Small Heterocycles Using Stoichiometric Metals2.1 Lithium-Mediated Electrophilic Ring Opening of Epoxides and Oxetanes2.2 Chromium-Mediated Electrophilic Ring Opening of Vinyl Epoxides2.3 Tin-Mediated Electrophilic Ring Opening of Vinyl Epoxides2.4 Samarium-Mediated Electrophilic Ring Opening of Vinyl and Alkynyl Epoxides2.5 Titanium-Mediated Electrophilic Ring Opening of Epoxides2.6 Platinum, Palladium, and Nickel-Mediated Electrophilic Ring Opening of 1,1-Dimethyl Ethylene Oxide3 Catalytic Electrophilic Ring Opening of Small Heterocycles3.1 Titanium-Catalyzed Electrophilic Ring Opening of Epoxides3.2 Palladium-Catalyzed Electrophilic Ring Opening of Vinyl and Alkynyl Small Heterocycles3.3 Iron-Catalyzed Electrophilic Ring Opening of Oxetanes3.4 Scandium-Catalyzed Electrophilic Ring Opening of Vinyl Epoxides3.5 Iridium-Catalyzed Electrophilic Ring Opening of 2-Methyl 2-Vinyl­oxiranes3.6 Nickel-Catalyzed Electrophilic Ring Opening of Epoxides and Aziridines3.7 Nickel–Titanium-Cocatalyzed Electrophilic Ring Opening of Epoxides4 Summary

Aluminium triflate as catalyst for epoxide ring-opening and esterification reactions — Mechanistic aspects

2005 ◽  
Vol 83 (6-7) ◽  
pp. 854-861 ◽  
Author(s):  
Yvette M Terblans ◽  
Johannes J Huyser ◽  
Michelle Huyser ◽  
Michael J Green ◽  
Desmond A Young ◽  
...  
Keyword(s):  
Ring Opening ◽  
Epoxide Ring ◽  
Epoxide Ring Opening ◽  
Low Concentrations ◽  
Ring Opening Reactions ◽  
Ring Opening Of Epoxides ◽  
Molecular Modeling Studies ◽  
Esterification Reactions ◽  
Active Intermediates ◽  
Formation Energies

Al(CF3SO3)3 is a highly effective catalyst for the ring opening of epoxides with methanol, as well as for the esterification of carboxylic acids with alcohols. Factors that influence the rate of the ring opening of butene oxide with methanol and the esterification of acetic acid with n-propanol and ethanol were investigated. It was found that low concentrations (e.g., ~5 ppm) of Al(CF3SO3)3 catalyze the ring-opening reactions, whereas considerably higher concentrations are required for esterification reactions. Molecular modeling studies suggest that these differences can be rationalized in terms of the formation energies of the active intermediates of these reactions.Key words: epoxide, ring opening, esterification, aluminium triflate.

scholarly journals Environmentally benign and highly regioselective ring opening of epoxides accelerated by ultrasound irradiation

2016 ◽  
Vol 9 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Mohamed Mahmoud Nasef ◽  
Masoumeh Zakeri ◽  
Jahanbakhsh Asadi ◽  
Ebrahim Abouzari-Lotf ◽  
Arshad Ahmad ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ultrasound Irradiation ◽  
Environmentally Benign ◽  
Ring Opening Of Epoxides

ChemInform Abstract: Ring-Opening Reactions of Difluoro(methylene)cyclopropanes with Halogens and Amines.

ChemInform ◽  
2009 ◽  
Vol 40 (12) ◽  
Author(s):  
Xiao-Chun Hang ◽  
Qing-Yun Chen ◽  
Ji-Chang Xiao
Keyword(s):  
Ring Opening ◽  
Ring Opening Reactions

Substituent Effects in Mechanochemical Allowed and Forbidden Cyclobutene Ring-Opening Reactions

2021 ◽  
Author(s):  
Cameron L. Brown ◽  
Brandon H. Bowser ◽  
Jan Meisner ◽  
Tatiana B. Kouznetsova ◽  
Stefan Seritan ◽  
...  
Keyword(s):  
Ring Opening ◽  
Substituent Effects ◽  
Ring Opening Reactions

ChemInform Abstract: Discovery of μ-Opioid Selective Ligands Derived from 1-Aminotetralin Scaffolds Made via Metal-Catalyzed Ring-Opening Reactions.

ChemInform ◽  
2009 ◽  
Vol 40 (29) ◽  
Author(s):  
Chris Dockendorff ◽  
Shujuan Jin ◽  
Madeline Olsen ◽  
Mark Lautens ◽  
Martin Coupal ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Reactions ◽  
Selective Ligands ◽  
Metal Catalyzed

scholarly journals Stereoselective Synthesis of Tetraalkyl Cyclobutene-1,2,3,4-tetracarboxylates. Synthesis of Tetraalkyl (Z,Z)-Buta-1,3-diene-1,2,3,4-tetracarboxylates

1999 ◽  
Vol 23 (8) ◽  
pp. 512-513
Author(s):  
Issa Yavari ◽  
Farahnaz Nourmohammadian
Keyword(s):  
Ring Opening ◽  
Wittig Reaction ◽  
Stereoselective Synthesis ◽  
Intramolecular Wittig Reaction ◽  
Ring Opening Reactions ◽  
Boiling Toluene

Tetraalkyl cyclobutene-1,2,3,4-tetracarboxylates, prepared by intramolecular Wittig reaction between a vinylphosphonium salt and diethyl 2-oxobutanedioate, undergo electrocyclic ring-opening reactions, in boiling toluene, to produce highly electron-deficient 1,3-dienes.

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