Direct 2-Pyridyl-Alkylation of Benzyne with N-Alkylpyridinium Salts

Abstract A 2-pyridyl-alkylation of benzyne using N-alkylpyridinium salts has been developed under either photochemical or thermal conditions. This metal-free dicarbofunctionalization of benzyne undergoes a de Mayo-type process including cascade dearomative [3+2] cycloaddition and rearomative ring-opening reaction. An electron-deficient N-cyclic alkyl group was necessary. A formal ortho-C–H arylation of pyridine has been achieved.