TITLE:
Regioselectivity Differentiation in Metalations of 3,5-Dichloro-Tertiary versus Secondary Benzamides
AUTHORS:
Francesca Khani, Tina Fleming, Carleton Collins, Erica Tabakin, Lynn M. Bradley, David A. Hunt
KEYWORDS:
Directed Ortho-Metalation, Complex-Induced Proximity Effects (CIPE), 3, 5-Dichlorobenzamides
JOURNAL NAME:
International Journal of Organic Chemistry,
Vol.6 No.2,
June
3,
2016
ABSTRACT: Metalation regioslectivity of 3,5-dichlorobenzamides is a function of the type of amide (secondary versus tertiary) used in the sequence. Metalation at the 2-position (adjacent to the carboxamide functional group) occurs when the secondary benzamide is metalated with sec-butyllithium/ TMEDA mediated through complex-induced proximity effects (CIPE) process, whereas metalation with sec-butyllithium/TMEDA occurs exclusively at the 4-position when the tertiary benzamide is used under identical reaction conditions.