Artículos de revistas
Regioselectivity of the nitration of phenol by acetyl nitrate adsorbed on silica gel
Tetrahedron. Pergamon-elsevier Science Ltd, v. 55, n. 22, n. 6733, n. 6738, 1999.
de Oliveira, AP
The reaction of phenol with acetyl nitrate in chloroform gives nitrophenol with an ortho/para ratio of 1.8. This ratio increase to 13.3 when the reaction was carried out with acetyl nitrate pre-adsorbed on dry silica gel. Silica may be acting as a template to bring phenol close to acetyl nitrate by hydrogen bonds forming a ternary complex, which undergoes a six-center rearrangement to o-nitrophenol. The formation of this ternary complex is evaluated by ab initio molecular orbital calculation, (C) 1999 Elsevier Science Ltd. All rights reserved.552267336738