scholarly journals Synthesis and evaluation of new guanidine-thiourea organocatalyst for the nitro-Michael reaction: Theoretical studies on mechanism and enantioselectivity

2012 ◽  
Vol 8 ◽  
pp. 1485-1498 ◽  
Author(s):  
Tatyana E Shubina ◽  
Matthias Freund ◽  
Sebastian Schenker ◽  
Timothy Clark ◽  
Svetlana B Tsogoeva
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Solvent Effects ◽  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Diethyl Malonate ◽  
Theoretical Studies ◽  
Michael Addition Reaction ◽  
The Michael Addition

A new guanidine-thiourea organocatalyst has been developed and applied as bifunctional organocatalyst in the Michael addition reaction of diethyl malonate to trans-β-nitrostyrene. Extensive DFT calculations, including solvent effects and dispersion corrections, as well as ab initio calculations provide a plausible description of the reaction mechanism.

Efficient Synthesis of 3-Amino-1,5-benzodiazepine-2-one Derivatives

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1183-1186 ◽  
Author(s):  
Nobuhiro Obara ◽  
Takeshi Watanabe ◽  
Tomohiro Asakawa ◽  
Toshiyuki Kan ◽  
Takao Tanaka
Keyword(s):  
Michael Addition ◽  
Convenient Method ◽  
Addition Reaction ◽  
Efficient Synthesis ◽  
Michael Addition Reaction ◽  
One Pot ◽  
Simple Method ◽  
The Michael Addition

A convenient method for synthesizing 3-amino-1,5-benzodiazepine-2-one via the Michael addition reaction of o-phenylenediamine with dehydroalanine ester derivatives, followed by cyclization, was developed. This simple method was used to obtain a variety of N-substituted 3-amino-1,5-benzodiazepine-2-ones in one pot with good yields.

Use of (R)-Mandelic Acid as Chiral Co-Catalyst in the Michael Addition Reaction Organocatalyzed by (1S,4S)-2-Tosyl-2,5-diazabicyclo[2.2.1]heptane under Solvent-Free Conditions

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
C. Gabriela Ávila-Ortiz ◽  
Manuel López-Ortiz ◽  
Alberto Vega-Peñaloza ◽  
Ignacio Regla ◽  
Eusebio Juaristi
Keyword(s):  
Michael Addition ◽  
Mandelic Acid ◽  
Addition Reaction ◽  
Solvent Free ◽  
Reaction Intermediates ◽  
Michael Addition Reaction ◽  
Co Catalyst ◽  
Co Catalysts ◽  
Solvent Free Conditions ◽  
The Michael Addition

AbstractThis article describes a study on the Michael addition reaction of cyclohexanone to nitroolefins catalyzed by the chiral secondary amine (1S,4S)-2-tosyl- 2,5-diazabicyclo[2.2.1]heptane. Reactions were carried out under solvent-free conditions to make them more environmentally friendly. Initially, the observed diastereoand enantioselectivities were moderate to good, but were significantly improved by lowering the reaction temperature. Furthermore, a variety of chiral acids were also tested as co-catalysts in both of their enantiomeric forms, which revealed that (R)-mandelic acid affords excellent results in terms of yield and stereoselectivity. Monitoring the reaction by MS-TOF allowed for the detection of key reaction intermediates, and a reasonable reaction mechanism in which both catalysts are involved is proposed.

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