Regio- and Chemoselective Addition of Mixed Copper, Zinc Benzylic Organometallics to Functionalized Pyridinium Salts: A Facile Synthesis of Functionalized 4-Benzylpyridines
2′,3-Disubstituted 4-benzylpyridines 4 were synthesized in good yield by reaction of mixed copper, zinc benzylic organometallics 1 with 3-substituted 1-(ethoxycarbonyl)pyridinium chlorides 2 followed by sulfur oxidation under reflux in decalin.
Four‐Selective Pyridine Alkylation via Wittig Olefination of Dearomatized Pyridylphosphonium Ylides
作者:Patrick J. Fricke、Ryan D. Dolewski、Andrew McNally
DOI:10.1002/anie.202109271
日期:2021.9.20
to synthesize alkylated pyridines are valuable because these structures are prevalent in pharmaceuticals and agrochemicals. We have developed a distinct approach to construct 4-alkylpyridines using dearomatized pyridylphosphonium ylide intermediates in a Wittig olefination-rearomatization sequence. Pyridine N-activation is key to this strategy, and N-triazinylpyridinium salts enable coupling between