Oxidative Aminopyridylation of Maleimides and 1, 4‐Quinones with N‐Aminopyridinium Ylides at Room Temperature in the Absence of External Reagents

Abstract

Abstract. Herein we have reported an expedient di‐functionalization of such versatile scaffolds. By harnessing an under explored reactivity of N‐aminopyridinium ylides, we have developed an aminopyridylation of N‐substituted maleimides and 1, 4‐quinones at room temperature in 2‐methylTHF without any external reagents. The [3+2] cycloaddition of N‐aminopyridinium ylides generate the corresponding cycloadduct with various maleimides and 1, 4‐quinone substrates, which rapidly undergoes oxidation at the alkene moiety under open air, inducing a considerable driving force, thermodynamically, to facilitate aromatisation of the pyridine and a subsequent homolytic cleavage of the N‐N bond to generate the desired 2, 3‐aminopyridylated products in good to excellent yield. Experimental and computational studies clarify the reaction mechanism. Keywords: Aminopyridylation; N‐aminopyridinium ylides; maleimides; 1, 4‐quinones; [3+2] cycloaddition