Pyridinium N-2′-pyridylaminide: synthesis of 3-aryl-2-aminopyridines through an intramolecular radical process

Abstract

Abstract-Tris(trimethylsilyl)silane (TTMSS) and azobisisobutironitrile (AIBN) promote the intramolecular heteroarylation of arenesulfonamides with pyridyl radicals under thermal conditions. The arenesulfonamides are easily prepared from pyridinium N-2 0 -pyridylaminide. The heteroarylation process involves pyridyl radical cyclization and ipso substitution. q

α-Amidation of Cyclic Ethers Catalyzed by Simple Copper Salt and a Mild and Efficient Preparation Method for α,ϖ-Amino Alcohols

“…Nitrene insertion into C−H bonds catalyzed by transition metal complexes is an attractive methodology for the construction of C−N bonds and many interesting organic molecules. − Such reactions could play a key role in the preparation of many natural products and pharmacologically active compounds …”

A New Class of Pyrazolopyridine Nucleus with Fluorescent Properties, Obtained through Either a Radical or a Pd Arylation Pathway from N-Azinylpyridinium N-Aminides

“…This nitrogen in turn induces a partial negative charge on the pyridinium ring, thus reducing its electron-poor character. Taking into account these premises and the previously reported work on the synthesis and reactivity of N -acylaminides, , additional experiments were carried out on the N -acyl salts 17 − 20 . Acylation on the N -exocyclic nitrogen could partially neutralize its electron-donating effect on both the pyridinium and 2-aminopyridine rings.…”

Site-Selective Cross-Coupling of Polyhalogenated Arenes and Heteroarenes with Identical Halogen Groups

“…Pyridinium N -(3′,5′-dibromopyrid-2′-yl)­aminides (e.g., 173a ) − have been employed as building blocks in the synthesis of various azine derivatives. − When they possess two C–Br bonds, these compounds are primed to undergo late-stage modifications via cross-coupling reactions. Accordingly, Alvarez-Builla and coworkers observed that upon subjecting these compounds to Suzuki–Miyaura coupling conditions with one equivalent of a boronic acid, substitution occurred exclusively at C3 to afford the monocoupled product ( 174 ) as the major product (Scheme ).…”