para-Selective radical alkylation of pyridines with diacyl peroxides and peresters†
Abstract
Herein, a practical method for the para-selective alkylation of various pyridines using the corresponding oxazino pyridine intermediates and cheap alkyl carboxylic acid-derived diacyl peroxides or peresters as alkyl radical precursors and internal oxidants is reported. The transformation proceeds in the absence of any transition metal catalyst, is easy to scale up and can be used in consecutive radical para,ortho-difunctionalization.