Theoretical study on mechanism of cinchona alkaloids catalyzed asymmetric conjugate addition of dimethyl malonate to β-nitrostyrene

2014 ◽  
Vol 114 (10) ◽  
pp. 642-651 ◽  
Author(s):  
Haiyang Jiang ◽  
Yanwei Sun ◽  
Huiling Liu ◽  
Xuri Huang
Keyword(s):  
Theoretical Study ◽  
Conjugate Addition ◽  
Cinchona Alkaloids ◽  
Dimethyl Malonate

scholarly journals A Remarkably Efficient Phase-Transfer Catalyzed Amination of α-Bromo-α, β-Unsaturated Ketones in Water

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Alemayehu Mekonnen ◽  
Alemu Tesfaye
Keyword(s):  
Quaternary Ammonium ◽  
Phase Transfer ◽  
Conjugate Addition ◽  
Quaternary Ammonium Salts ◽  
Cinchona Alkaloids ◽  
Ammonium Salts ◽  
Alkylation Reaction ◽  
Pt Catalysts ◽  
Unsaturated Ketones ◽  
Catalytic Performances

Tandem conjugate addition–alkylation reaction of various amines with α-bromo-α, β-unsaturated ketones resulted in near-quantitative conversions into the corresponding aziridines when the reaction was carried out in the presence of 10 mol% of phase-transfer, PT catalysts in water. Some chiral quaternary ammonium salts derived from Cinchona alkaloids were investigated as water-stable PT catalysts. The scope and limitations of the reaction have also been investigated. The catalytic performances were significantly improved in comparison with the corresponding ordinary quaternary ammonium salt catalysts, and excellent yields (81%–96%) were obtained. Although an increase in the rate of aziridination has been accomplished, no stereoselectivity was observed. The positive values of the protocol have been confirmed.

Studies on gibberellin synthesis. The preparation of phenanthrenoid intermediates for the synthesis of gibberellin A21

1981 ◽  
Vol 34 (9) ◽  
pp. 1913 ◽  
Author(s):  
LN Mander ◽  
GJ Potter ◽  
SG Pyne ◽  
M Woolias
Keyword(s):  
Conjugate Addition ◽  
Dimethyl Malonate ◽  
Conventional Methods

Methyl 3-(6'-oxo-4'-methoxy-5',6',7',8'-tetrahydronaphthalen-1'-yl)propanoate (11) was converted by conventional methods into diazoketone (17) which underwent acid-promoted cyclization to dienone (18). Refunctionalization gave dienone (20) which was subjected to a tandem alkylation, conjugate addition process with the sodium enolate of dimethyl malonate to furnish a 2: 1 mixture of dimethyl (2RS,8aSR,10aSR)-2-methoxymethyloxy-10,12-dioxo-2,3,4,5,6,7,8a,9,10-decahydro-1 H-2,10a-ethano- phenanthrene-8,8-dicarboxylate (21) and its 8a-epimer, respectively. Subsequent manipulations led to lactone (26), but attempts to convert this compound into a gibbane derivative were unsuccessful.

A Theoretical Study On Rh(I) Catalyzed Enantioselective Conjugate Addition Reactions of Fluoroalkylated Olefins

2014 ◽  
Vol 33 (19) ◽  
pp. 5111-5119 ◽  
Author(s):  
Esra Boz ◽  
Z. Pınar Haşlak ◽  
Nurcan Ş. Tüzün ◽  
F. Aylin Sungur Konuklar
Keyword(s):  
Theoretical Study ◽  
Conjugate Addition ◽  
Addition Reactions

Epalons: Synthesis of New 16α-Carboxymethyl Derivatives

1999 ◽  
Vol 64 (9) ◽  
pp. 1479-1484 ◽  
Author(s):  
Barbora Slavíková ◽  
Alexander Kasal
Keyword(s):  
Formic Acid ◽  
Conjugate Addition ◽  
Dimethyl Malonate ◽  
Diethyl Azodicarboxylate

The title compounds (16α-carboxymethyl-3α-hydroxy-5α-pregnan-20-one and its sodium and triethylammonium salts) were prepared from 20-oxopregna-5,16-dien-3β-yl acetate by conjugate addition of dimethyl malonate and decarboxylation. Inversion of configuration at carbon C-3 was carried out by Mitsunobu acylation with diethyl azodicarboxylate and formic acid in the presence of triphenylphosphine.

Asymmetric conjugate addition of azide to α,β-unsaturated nitro compounds catalyzed by cinchona alkaloids

Tetrahedron ◽  
2007 ◽  
Vol 63 (26) ◽  
pp. 5849-5854 ◽  
Author(s):  
Martin Nielsen ◽  
Wei Zhuang ◽  
Karl Anker Jørgensen
Keyword(s):  
Conjugate Addition ◽  
Nitro Compounds ◽  
Cinchona Alkaloids
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