نتایج جستجو برای: epoxy ring opening

تعداد نتایج: 183008  

Journal: :Chemcatchem 2022

Sequence selective ring-opening terpolymerisation (ROTERP) allows the design of block polymerisation cascades with three distinct mechanistic cycles. Ring-opening (ROP), copolymerisation (ROCOP) and ROTERP can be combined in where onset most complex process supresses occurrence simpler ones. The furthermore enable incorporation different heteroallenes between blocks.

Journal: :Physical chemistry chemical physics : PCCP 2009
Simone Draxler Thomas Brust Stephan Malkmus Jessica A DiGirolamo Watson J Lees Wolfgang Zinth Markus Braun

The ring-opening reaction of a trifluorinated indolylfulgide has been studied as a function of temperature and optical pre-excitation where it was found that reaction times decreased as temperature increased from 10.3 ps at 12 degrees C to 7.6 ps at 60 degrees C. Simultaneously, the quantum yields for the ring-opening reaction grew from 3.1% (12 degrees C) to 5.0% (60 degrees C). When the react...

2017
Katrina Tait Alysia Horvath Nicolas Blanchard William Tam

The acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicylic alkene using alcohol nucleophiles were investigated. Although this acid-catalyzed ring-opening reaction did not cleave the cyclopropane unit as planned, this represent the first examples of ring-openings of cyclopropanated 3-aza-2-oxabicyclo[2.2.1]alkenes that lead to the cleavage of the C-O bond instead of the N-...

1998
KASSOUM NACRO CHANTAL ZEDDE MICHEL BALTAS LILIANE GORRICHON REINHARD NEIER

A number of 2,3-epoxy alcohol derivatives (1–16), obtained either as racemates or through the Sharpless asymmetric epoxidation reaction, were studied on a Chiralcel OD column. Nearly all compounds exhibit good enantioselective resolution on this chiral support. The order of elution of enantiomers is reversed between nerol and geraniol compounds. For 2,3-epoxy alcohols bearing a remote alkoxy (o...

Journal: :E-polymers 2021

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl p -tert-butylphenol, 4-methoxyphenol presence tetrafluoroboric acid as catalyst. The SOPs characterized FTIR, 1 H NMR, GPC, viscosity, hydroxyl numbers. Compared ESO...

Journal: :Organometallics 2010
Benjamin K Keitz Robert H Grubbs

Ru-based olefin metathesis catalysts containing carbohydrate-derived NHCs from glucose and galactose were synthesized and characterized by NMR spectroscopy. 2D-NMR spectroscopy revealed the presence of Ru-C (benzylidene) rotamers at RT and the rate of rotation was measured using magnetization transfer and VT-NMR spectroscopy. The catalysts were found to be effective at ring-opening metathesis p...

Journal: :The journal of physical chemistry. A 2015
Zeb C Kramer Barry K Carpenter Gregory S Ezra Stephen Wiggins

Following previous work [J. Chem. Phys. 2013, 139, 154108] on a simple model of a reaction with a post-transition state valley ridge inflection point, we study the chemically important example of the electrocyclic cyclopropyl radical ring-opening reaction using direct dynamics and a reduced dimensional potential energy surface. The overall reaction requires con- or disrotation of the methylenes...

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