Ab InitioCalculations on the 5-exoversus 6-endoCyclization of 1,3-Hexadiene-5-yn-1-yl Radical:  Formation of the First Aromatic Ring in Hydrocarbon Combustion

2000 ◽  
Vol 122 (46) ◽  
pp. 11416-11422 ◽  
Author(s):  
Santiago Olivella ◽  
Albert Solé
Keyword(s):  
Aromatic Ring ◽  
Radical Formation ◽  
Hydrocarbon Combustion

Photocyclisations de cétoacétals aromatiques en vue d'une approche synthétique de la crombénine

1990 ◽  
Vol 68 (7) ◽  
pp. 1251-1257 ◽  
Author(s):  
Françoise Cottet ◽  
Louis Cottier ◽  
Gérard Descotes
Keyword(s):  
Aromatic Ring ◽  
Side Reaction ◽  
Radical Formation ◽  
Type Ii ◽  
Benzyl Radical ◽  
Norrish Type

Crombenin 1 is a spiropeltogynoid compound with a spiroacetal moiety. A similar structure was synthesized starting from an orthocarbonylphenoxyisochroman by a Norrish type II photocyclisation. With an isochroman compound, the aromatic ring induces benzyl radical formation to give chiefly a bicyclic [4.3.1] derivative. However, with the introduction of electron-withdrawing or bulky substituents at C-4′, this side reaction is limited and the spiranic product becomes preponderant. Keywords: acetals, isochroman, photocyclisation, spiroacetals.

scholarly journals Phenyl radical + propene: a prototypical reaction surface for aromatic-catalyzed 1,2-hydrogen-migration and subsequent resonance-stabilized radical formation

2018 ◽  
Vol 20 (19) ◽  
pp. 13191-13214 ◽  
Author(s):  
Zachary J. Buras ◽  
Te-Chun Chu ◽  
Adeel Jamal ◽  
Nathan W. Yee ◽  
Joshua E. Middaugh ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Alkyl Chain ◽  
Radical Formation ◽  
Phenyl Radical ◽  
Hydrogen Migration ◽  
Reaction Surface

H-Shifts in the alkyl chain catalyzed by an aromatic ring (green pathway).

Photocatalytic Alkylation of Pyrroles and Indoles with α-Diazo Esters

2019 ◽  
Author(s):  
Łukasz Ciszewski ◽  
Jakub Durka ◽  
Dorota Gryko
Keyword(s):  
Aromatic Compounds ◽  
Reaction Pathway ◽  
Alkylating Agents ◽  
Catalytic Amount ◽  
Radical Formation ◽  
Reaction Selectivity ◽  
Diazo Esters ◽  
Electron Withdrawing Substituents

This article describes direct photoalkylation of electron-rich aromatic compounds with diazo compoiunds. C-2 alkylated indoles and pyrroles are obtained with good yields even though the photocatalyst (Ru(bpy)3Cl2) loading is as low as 0.075 mol %. For substrates bearing electron-withdrawing substituents the addition of a catalytic amount of N,N-dimethyl-4-methoxyaniline is required. Both EWG-EWG and EWG-EDG substituted diazo esters are suitable as alkylating agents. The reaction selectivity and mechanistic experiments suggest that carbenes/carbenoid intermediates are not involved in the reaction pathway, instead radical formation is proposed.

Visible Light-Induced Sulfonylation/Arylation of Styrenes in a Double Radical Three-Component Photoredox Reaction

2019 ◽  
Author(s):  
Benjamin Lipp ◽  
Lisa Marie Kammer ◽  
Murat Kucukdisli ◽  
Adriana Luque ◽  
Jonas Kühlborn ◽  
...  
Keyword(s):  
Visible Light ◽  
Radical Formation ◽  
Three Component Reaction ◽  
Broad Variety ◽  
Styrene Derivatives ◽  
Mechanistic Investigations

Simultaneous sulfonylation/arylation of styrene derivatives is achieved in a photoredox-catalyzed three-component reaction using visible light. A broad variety of difunctionalized products is accessible in mostly excellent yields and high diastereoselectivity. The developed reaction is scalable and suitable for the modification of styrene-functionalized biomolecules. Mechanistic investigations suggest the transformation to be operating through a designed sequence of radical formation and radical combination.<br>

Photoreaction of N-butyl 3,4-dimethoxy-6-nitrobenzamide with butylamine. A model study for lysine-directed photoaffinity labelling

1987 ◽  
Vol 52 (7) ◽  
pp. 1780-1785 ◽  
Author(s):  
Petr Kuzmič ◽  
Libuše Pavlíčková ◽  
Milan Souček
Keyword(s):  
Nitro Group ◽  
Aromatic Ring ◽  
Ultraviolet Irradiation ◽  
Title Compound ◽  
Reductive Coupling ◽  
Photoaffinity Labelling ◽  
Photolysis Rate ◽  
Model Study ◽  
A Minor

Ultraviolet irradiation of the title compound I in the presence of butylamine gave predominantly products of nucleophilic photosubstitution by the amine, i.e., nitroanilines IIa and IIb. Besides, small amounts of products of hydrolysis (phenol III) and reductive coupling (azoxybenzene IV) were also formed. Comparison of the overall photolysis rate of I with that of 3,4-dimethoxy-1-nitrobenzene (V) indicates a minor loss of reactivity, most probably due to some deviation from coplanarity of the activating nitro group and the aromatic ring.

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