Reaction of Pyridine‐<i>N</i>‐Oxides with Tertiary sp<sup>2</sup>‐<i>N</i>‐Nucleophiles: An Efficient Synthesis of Precursors for <i>N</i>‐(Pyrid‐2‐yl)‐Substituted <i>N</i>‐Heterocyclic Carbenes
Dmitry I. Bugaenko, M. A. Yurovskaya, Alexander V. Karchava
Abstract
Abstract N ‐(Pyrid‐2‐yl)‐substituted azolium and pyridinium salts, precursors for hybrid NHC‐containing ligands, were obtained with excellent regioselectivity, employing a deoxygenative CH‐functionalization of pyridine‐ N ‐oxides with substituted imidazoles, thiazoles, and pyridine. Unlike the traditional S N Ar‐based methods, this approach provides high yields for substrates bearing substituents of different electronic nature. The utility of azolium and pyridinium salts thus prepared was also highlighted by the synthesis of pyridyl‐substituted imidazolyl‐2‐thione, benzodiazepine as well as 2‐aminopyridines. magnified image
Topics & Concepts
PyridiniumChemistryPyridineRegioselectivityNucleophileMedicinal chemistrySurface modificationCombinatorial chemistryOrganic chemistryCatalysisPhysical chemistryN-Heterocyclic Carbenes in Organic and Inorganic ChemistryCatalytic Cross-Coupling ReactionsCatalytic C–H Functionalization Methods