NHC-catalyzed nucleophilic dearomatization of alkyl pyridiniums has been achieved to generate 1,4-dihydropyridines with high enantioselectivity. This is a rare example of catalytic, asymmetric addition of a nucleophile to the activated pyridinium that prefers C-4 functionalization leading to the 1,4-dihydropyridine with high selectivity.

The silyl enol ether derivatives of ketones or esters tethered by a hydrocarbon or ether linkage to the 3-position of a pyridine ring undergo dearomatising nucleophilic attack on the ring once it is activated (as an acylpyridinium species) by the addition of methyl chloroformate. The bicyclic dihydropyridine products are in some cases unstable, but may be isolated after hydrogenation as fused b...

as a continuous research for discovery of new cox-2 inhibitors, chemical synthesis, in vitro biological activity and molecular docking study of anew group of 1,4-dihydropyridine (dhp) derivatives were presented. novel synthesized compounds possessing a cox-2 so2me pharmacophore at the para position of c-4 phenyl ring, different hydrophobic groups (r1) at c-2 position and alkoxycarbonyl groups (...

The interaction of 1,4-dihydropyridine derivatives with their receptors on voltage-dependent calcium channels in cardiac membranes was studied to determine if there are basic differences in the binding properties of ligands that cause inhibition or activation of calcium channels. The binding characteristics of 6 pure stereoisomers, (-) and (+)202-791, (-) and (+)Bay k 8644, (-) and (+)PN 200-11...

Ca2+ stores were studied in a preparation of freshly dissociated terminals from hypothalamic magnocellular neurons. Depolarization from a holding level of -80 mV in the absence of extracellular Ca2+ elicited Ca2+ release from intraterminal stores, a ryanodine-sensitive process designated as voltage-induced Ca2+ release (VICaR). The release took one of two forms: an increase in the frequency but...

A large-conductance calcium channel in chicken dorsal root ganglion neurons was studied with patch-clamp recordings of unitary currents. In addition to the conventional pattern of Ca-channel gating previously described in neurons ("mode 1"), we observed a different form of gating behavior ("mode 2"). Unlike the brief (approximately equal to 1 ms) openings in mode 1, mode 2 openings tend to be l...