نتایج جستجو برای: amino alcohols

تعداد نتایج: 217020  

Journal: :Physical review letters 2014
C Gainaru R Figuli T Hecksher B Jakobsen J C Dyre M Wilhelm R Böhmer

Liquids composed of small-molecule monohydroxy alcohols are demonstrated to display rheological behavior typical for oligomeric chains. This observation was made possible by rheological experiments in which more than seven decades in frequency and more than five decades on the mechanical modulus scale are covered. The singly hydrogen-bonded monohydroxy alcohols were chosen because they display ...

Journal: :Organic & biomolecular chemistry 2012
Ramalingam Boobalan Chinpiao Chen Gene-Hsian Lee

A series of Schiff base ligands were synthesized from (1R)-camphor. Under the optimal conditions, (+)-SBAIB-a, 10 was found to be an excellent catalyst for the enantioselective addition of phenylacetylene to various aldehydes without utilizing either achiral additives or Ti(O(i)Pr)(4). This approach yielded (R)-propargylic alcohols in extremely high yields (up to 99%) and excellent enantioselec...

2017
Per-Olof Syren Florian Le Joubioux Yesmine Ben Henda Thierry Maugard Karl Hult Marianne Graber Per-Olof Syrén

Journal: :Molecules 2012
Fernanda C G Barbosa Juliano C R Freitas Caio F Melo Paulo H Menezes Roberta A Oliveira

An efficient method for the allylation of aldehydes containing a broad range of functional groups using potassium allyltrifluoroborate is described. The reaction utilizes a catalytic amount of 18-C-6 in biphasic media under open atmosphere and room temperature to provide the corresponding homoallylic alcohols in high yields and without the necessity of any subsequent purification.

Journal: :Organic letters 2000
Lin RajanBabu

Primary and secondary alcohols react with vinyl or isopropenyl acetate at room temperature in the presence of catalytic amounts (0.05-1 mol %) of Y5(OiPr)13O to give the corresponding esters. In selected cases, the yttrium catalyst promotes the selective O-acylation of amino alcohols without the formation of the amide. Enol esters also react with alpha-amino acid esters in the absence of a cata...

Journal: :The Journal of organic chemistry 2003
Ji Duck Kim Ok Pyo Zee Young Hoon Jung

The diastereoselective synthesis of unsaturated aromatic 1,2-amino alcohols can be achieved on an epimeric mixture of optically active allylic ethers having a hydroxyl group attached to an allylic chiral center to the pi-system using chlorosulfonyl isocyanate. These reactions produced the unsaturated anti-1,2-amino alcohols either exclusively or predominantly only for aromatic derivatives. The ...

2002
Lothar W. Bieber Maria C. F. de Araújo

Two alternative and complementary one-pot procedures for the direct transformation of 2-amino alcohols to N-tosyl aziridines are presented. The unsubstituted parent compound and its less hindered homologues can be obtained in high yields by tosylation and in situ cyclisation effected by potassium hydroxide in water/dichloromethane. Higher substituted amino alcohols give better yields using pota...

2015
Graeme Barker David G Johnson Paul C Young Stuart A Macgregor Ai-Lan Lee

Gold(I)-catalysed direct allylic etherifications have been successfully carried out with chirality transfer to yield enantioenriched, γ-substituted secondary allylic ethers. Our investigations include a full substrate-scope screen to ascertain substituent effects on the regioselectivity, stereoselectivity and efficiency of chirality transfer, as well as control experiments to elucidate the mech...

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: :Chirality 2014
Kazushige Matsumoto Jun Sawayama Shotaro Hirao Nagatoshi Nishiwaki Ryuichi Sugimoto Kazuhiko Saigo

An improved method, which is highly reproducible, was developed for the enantioseparation of racemic O-ethyl phenylphosphonothioic acid (1a) with brucine by introducing seeding to a supersaturated solution of the diastereomeric salt mixture. The present method gave both diastereomeric salts in high yields with a diastereomeric ratio of >99.5:0.5 upon choosing the crystallization solvent (MeOH f...

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