New possible ionic structures in Wittig reaction: Analysis of stability and rotation barriers by semiempirical PM3 method

Autor: Maria Mracec, Aurelia Pascariu, Mircea Mracec, Stefan Berger
Rok vydání: 2007
Předmět:
Zdroj: International Journal of Quantum Chemistry. 107:1782-1793
ISSN: 1097-461X
0020-7608
DOI: 10.1002/qua.21298
Popis: For the Wittig reaction between butylidentriphenylphosphorane and benzaldehyde studied previously using NMR spectroscopy, three ionic intermediates have been proposed in order to explain the “stereochemical drift” (different ratio in oxaphosphetane stereoisomers compared with the ratio of the final Z/E olefins). In this paper, the PM3 semiempirical MO method was applied on the proposed ionic intermediates. Two of the ionic intermediates could lead to a shift of the reaction towards the final products, olefins and phosphine oxide, while the third intermediate could be implicated in a retro-Wittig reaction. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Databáze: OpenAIRE
Nepřihlášeným uživatelům se plný text nezobrazuje