Synthesis and Reactivity of Imide-Derived Bisvinyl Phosphates. Reactivity of 2,6-Disubstituted 1,4-Dihydropyridines
摘要:
Symmetrical and unsymmetrical 2,6-disubstituted dihydropyridines were prepared in high yields under mild conditions using the Suzuki and Stille Pd-catalyzed coupling reactions of imide-derived bisvinyl phosphates with a range of aryl, heteroaryl, and alkenyl moieties. The alkylation reaction at C-4 easily afforded original tri- and tetrasubstituted dihydropyridines. Hydrolysis of the latter under acidic condition provided efficiently either open-chain 1,5-diketones or di- or trisubstituted pyridines.
Direct access to 2-(hetero)arylated pyridines from 6-substituted 2-bromopyridines via phosphine-free palladium-catalyzed C–H bond arylations: the importance of the C6 substituent
A phosphine-free palladium catalytic system was found to be very active to promote C–H bond activation/arylation of 5-membered ring heterocycles or electron-deficient arenes with 6-substituted 2-bromopyridines, providing a general, straightforward and environmentally benign synthetic approach to a broad variety of 2-(hetero)arylpyridines. The reactivity of 2-bromopyridines is strongly dependent on
Symmetrical and unsymmetrical 2,6-disubstituted dihydropyridines were prepared in high yields under mild conditions using the Suzuki and Stille Pd-catalyzed coupling reactions of imide-derived bisvinyl phosphates with a range of aryl, heteroaryl, and alkenyl moieties. The alkylation reaction at C-4 easily afforded original tri- and tetrasubstituted dihydropyridines. Hydrolysis of the latter under acidic condition provided efficiently either open-chain 1,5-diketones or di- or trisubstituted pyridines.