113016-90-3Relevant academic research and scientific papers
Arene Cyanation via Cation-Radical Accelerated-Nucleophilic Aromatic Substitution
Holmberg-Douglas, Natalie,Nicewicz, David A.
supporting information, p. 7114 - 7118 (2019/09/07)
Herein we describe a cation radical-accelerated-nucleophilic aromatic substitution (CRA-SNAr) of alkoxy arenes utilizing a highly oxidizing acridinium photoredox catalyst and acetone cyanohydrin, an inexpensive and commercially available cyanide source. This cyanation is selective for carbon-oxygen (C-O) bond functionalization and is applicable to a range of methoxyarenes and dimethoxyarenes. Furthermore, computational studies provide a model for predicting regioselectivity and chemoselectivity in competitive C-H and C-O cyanation of methoxyarene cation radicals.
SUBSTITUENT EFFECTS IN AROMATIC PHOTOCHEMISTRY: UV IRRADIATION OF 3,4-DIMETHOXYBENZONITRILE AND 3,4-DIMETHOXYACETOPHENONE IN THE PRESENCE OF INORGANIC ANIONS
Kuzmic, Petr,Soucek, Milan
, p. 980 - 988 (2007/10/02)
Ultraviolet photolysis of 3,4-dimethoxybenzonitrile (Ia) and 3,4-dimethoxyacetophenone (IIa) in the presence of the hydroxide or cyanide anions leads to nucleophilic displacement of either the para or the meta methoxy substituent.The ratio of isomeric photoproducts is dependent upon the nature of the nucleophile.Photoreactions with the OH(-) anion leads exclusively to the substitution at C-3.On the other hand, both isomers are formed when acetophenone IIa is irradiated in the presence of CN(-), with the C-3/C-4 ratio ranging from 1:2 to 1:6 in dependence on the nucleophile concentration.These difference between the OH(-) and CN(-) anion are related to the results of a fluorescence quenching study which has revealed that only the observed for the quenching of the second excited state of Ia by the cyanide anion.This indicates several distinct quenching modes, in relation to the concentration dependence of regioselectivity.The activating power of -H, -CN, -COCH3, and -NO2 substituents, as measured by relative quantum yields of disappearance for 3,4-dimethoxy-R-substituted benzenes, is 1 : 2.5 : 5 : 580 and 1 : 1.5 : 6 : 1000 in their photoreactions with OH(-) and CN(-) anions, respectively.
