A study on the BF3 directed lithiation of 3-chloro- and 3-bromopyridine

resumo

The BF3-directed lithiation of 3-chloro- and 3-bromopyridine (1a and 1b, espectively) has been investigated. The reactions of 3-chloro- or 3-bromopyridine-BF3 adduct with LDA (1.3/1.1 equiv) followed by quenching with benzaldehyde or iodine exclusively gave the C-2 substituted products. However, when 2.2 equiv of LDA and dimethyl disulfide was used, a C-6 substituted product was obtained. Dilithiation of 1a and 1b has been studied with and without the involvement of BF3 complexation. The role of Li...F(BF3) interactions has been investigated by experimental and DFT calculations. (C) 2013 Elsevier Ltd. All rights reserved.

palavras-chave

REGIOSELECTIVE ORTHO-LITHIATION; DENSITY-FUNCTIONAL THEORY; HALOGEN-LITHIUM EXCHANGE; X-RAY-STRUCTURE; C-2 LITHIATION; TMSCH2LI-LIDMAE; BROMOPYRIDINES; METALATION; HALOPYRIDINES; PYRIDINES

categoria

Chemistry

autores

Dhau, JS; Singh, A; Kasetti, Y; Bhatia, S; Bharatam, PV; Brandao, P; Felix, V; Singh, KN

nossos autores

agradecimentos

We are thankful to the CSIR, New Delhi, India, for financial support. Additional support from SAP by UGC, New Delhi, is also acknowledged. We are also thankful to Mr. Avtar Singh, CIL, Punjab University, Chandigarh, for NMR spectra.

Partilhe este projeto

Publicações similares

Usamos cookies para atividades de marketing e para lhe oferecer uma melhor experiência de navegação. Ao clicar em “Aceitar Cookies” você concorda com nossa política de cookies. Leia sobre como usamos cookies clicando em "Política de Privacidade e Cookies".