Correction to Mechanisms and Transition States of 1,3-Dipolar Cycloadditions of Phenyl Azide with Enamines: A Computational Analysis

2013 ◽  
Vol 78 (10) ◽  
pp. 5115-5115 ◽  
Author(s):  
Steven A. Lopez ◽  
Morton E. Munk ◽  
K. N. Houk
Keyword(s):  
Computational Analysis ◽  
Transition States ◽  
Phenyl Azide ◽  
Dipolar Cycloadditions

Ab Initio Study of Solvent Effects on Rate of 1,3-Dipolar Cycloadditions of Benzonitrile Oxide and Various Dipolarophiles

2003 ◽  
Vol 2003 (2) ◽  
pp. 91-95 ◽  
Author(s):  
E. Rajaeian ◽  
M. Monajjemi ◽  
M.R. Gholami
Keyword(s):  
Hydrogen Bonding ◽  
Oxygen Atom ◽  
Water Molecule ◽  
Ab Initio ◽  
Solvent Effects ◽  
Transition States ◽  
Molecular Orbital Calculations ◽  
Interaction Energies ◽  
Ab Initio Study ◽  
Dipolar Cycloadditions

Ab initio molecular orbital calculations have been used to investigate the structures and the transition states of 1,3-dipolar cycloadditions between benzonitrile oxide with ethylene, cyclopentene, acrylonitrile and tetracyanoethylene in heptane and water: calculations reveal enhanced hydrogen bonding of a water molecule to the transition states for the cycloaddition 1,3-dipolar of reaction of benzonitrile oxide with cyclopentene, the optimal interaction energies being 0.7 kcal/mol more favourable for hydrogen bonding to the oxygen atom in the transition states than for the reactants.

scholarly journals Bifunctional Iminophosphorane Catalyzed Enantioselective Sulfa-Michael Addition to Unactivated α,β-Unsaturated Amides

2021 ◽  
Author(s):  
Daniel Rozsar ◽  
Michele Formica ◽  
Ken Yamazaki ◽  
Trevor Hamlin ◽  
Darren J. Dixon
Keyword(s):  
Carbonyl Group ◽  
Michael Addition ◽  
Computational Analysis ◽  
Transition States ◽  
Substantial Evidence ◽  
Reaction Conditions ◽  
Metal Free ◽  
Wide Range ◽  
Covalent Activation

<div>The first metal-free catalytic intermolecular enantioselective sulfa-Michael addition to unactivated <i>α</i>,<i>β</i>- unsaturated amides is described. Consistently high enantiomeric excesses, and yields were obtained over a wide range of alkyl thiol pronucleophiles and electrophiles under mild reaction conditions, enabled by a novel squaramide-based bifunctional iminophosphorane (BIMP) catalyst. Low catalyst loadings (2 mol%) were achieved on a decagram scale, demonstrating the scalability of the reaction. Computational analysis revealed the origin of the high enantiofacial selectivity, corresponding transition states, and provided substantial evidence for specific non-covalent activation of the carbonyl group of the <i>α</i>,<i>β</i>-unsaturated amide by the catalyst.</div>

scholarly journals Bifunctional Iminophosphorane Catalyzed Enantioselective Sulfa-Michael Addition to Unactivated α,β-Unsaturated Amides

2021 ◽  
Author(s):  
Daniel Rozsar ◽  
Michele Formica ◽  
Ken Yamazaki ◽  
Trevor Hamlin ◽  
Darren J. Dixon
Keyword(s):  
Carbonyl Group ◽  
Michael Addition ◽  
Computational Analysis ◽  
Transition States ◽  
Substantial Evidence ◽  
Reaction Conditions ◽  
Metal Free ◽  
Wide Range ◽  
Covalent Activation

<div>The first metal-free catalytic intermolecular enantioselective sulfa-Michael addition to unactivated <i>α</i>,<i>β</i>- unsaturated amides is described. Consistently high enantiomeric excesses, and yields were obtained over a wide range of alkyl thiol pronucleophiles and electrophiles under mild reaction conditions, enabled by a novel squaramide-based bifunctional iminophosphorane (BIMP) catalyst. Low catalyst loadings (2 mol%) were achieved on a decagram scale, demonstrating the scalability of the reaction. Computational analysis revealed the origin of the high enantiofacial selectivity, corresponding transition states, and provided substantial evidence for specific non-covalent activation of the carbonyl group of the <i>α</i>,<i>β</i>-unsaturated amide by the catalyst.</div>

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