RCu· BF 3 reacted with 1-ethoxycarbonylpyridinium chloride at the 4-position with almost complete regio-selectivity (> 99%) to afford the corresponding 1, 4-dihydropyridine derivatives in high yields (81–94%). The dihydropyridines were oxidized by oxygen to give 4- alkyl (aryl) pyridines (38–68%). Grignard reagents also reacted with 1-t- butyldimethylsilylpyridinium triflate with almost complete regioselectivity (> 99%) to afford ...