نتایج جستجو برای: Nucleophilic opening

تعداد نتایج: 54008  

Abolfazl Olyai Akbar Shabanikia Dariush Farkhani Mohammad Raouf Darvich,

Nucleophilic ring opening of dl and meso 1,1¢- dicyclohexenyl diepoxides by sodium azide in dioxane and aqueous alcoholic medium give the corresponding azidoalcohols. The obtention of departure diepoxides from diazidoalcohols by the reaction with sodium hydride shows the anti position of OH and N3 groups.

2007
Manas K. Ghorai Koena Ghosh

A highly regioselective SN2-type ring opening of 2-aryl-N-tosylaziridines with carbonyl compounds in the presence of a Lewis acid to afford various 1,3-oxazolidines and 1,2-amino alcohols in excellent yields and moderate to high enantioselectivity is described. The formation of non-racemic products provides convincing evidence for the SN2-type ring opening mechanism. 2007 Elsevier Ltd. All righ...

Journal: :Molecules 2010
Ana María Costero Salvador Gil Margarita Parra Pablo Rodríguez

The reactivity of dianions of carboxylic acids towards aziridines has been studied. Although, a similar reactivity to that of enolates from ketones, esters or amides has been observed, the method directly yields γ-aminoacids in one step. The method is complementary of previous results of enenediolate reactivity with other electrophiles. A comparative study with the reactivity of this enediolate...

Journal: :علوم 0

epoxyalcohols are useful intermediates in complex organic synthesis, and recently they have been recognized as versatile intermediates for synthesis of natural products. the treatments of cis and trans 2-(1-cyclohexenyl) cyclohexanol, separately with paranirto perbenzoic acid gave the corresponding 2-(1- cyclohexenyl) cyclohexanol oxide. on the other hand, 2-cyclohexylidene cyclohexanol oxide w...

Journal: :Chemical communications 2004
Per Restorp Peter Somfai

A divergent protocol for nucleophilic opening of vinyl epoxides with ethoxyacetylide has been developed and demonstrated to give complete regioselectivity depending on reaction conditions.

Journal: :Inorganic chemistry 2009
Rong-Zhen Liao Jian-Guo Yu Fahmi Himo

N-acyl-L-homoserine lactone hydrolase (AHL lactonase) is a dinuclear zinc enzyme responsible for the hydrolytic ring opening of AHLs, disrupting quorum sensing in bacteria. The reaction mechanism is investigated using hybrid density functional theory. A model of the active site is designed on the basis of the X-ray crystal structure, and stationary points along the reaction pathway are optimize...

Journal: :Organic & biomolecular chemistry 2011
I-Chi Lee Medel Manuel L Zulueta Chi-Rung Shie Susan D Arco Shang-Cheng Hung

Specific deuterated reference compounds were prepared to probe the stereoselectivity of the reductive ring opening of carbohydrate-based benzylidene-type acetals. AlD(3) revealed a retentive stereoselectivity probably through the rare S(N)i (internal nucleophilic substitution) mechanism. An S(N)1-like mechanism occurs in the acid-promoted regioselective BD(3)·THF- or Et(3)SiD-reductive ring ope...

Journal: :Organic letters 2002
Travis Dudding Ahmed M Hafez Andrew E Taggi Ty R Wagerle Thomas Lectka

We report a new method for the catalytic, asymmetric synthesis of beta-substituted aspartic acid derivatives in which the nucleophilic catalyst serves up to four discrete roles in a one-pot procedure: catalytic dehydrohalogenation of acid chlorides to form ketenes; catalytic dehydrohalogenation of alpha-chloroamines to form the corresponding imines; catalyzed [2 + 2]-cycloaddition to produce in...

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