Previous studies have suggested the presence of different types of calcium channels in different regions of stomatogastric neurons. We sought to pharmacologically separate these calcium channel types. We used two different preparations from different regions of stomatogastric neurons to screen a range of selective calcium channel blockers. The two preparations were isolated cell bodies in cultu...

Oxidation of different types of 1,4-dihydropyridines with diphenylpicrylhydrazyl (DPP) and benzoyl peroxide (Bz2O2) as free radical oxidizing agents to pyridine derivatives is reported and a mechanism for this oxidation is also proposed.

Acid treatment of densely substituted 2-silyl-1,2-dihydropyridines provides a new and convenient entry to reactive azomethine ylides that can (1) be protonated and reduced with high stereoselectivity to give piperidines, (2) participate in [3 + 2] dipolar cycloaddition to give tropanes, and (3) undergo a Nazarov-like 6-π electrocyclization that upon reduction give 2-azabicyclo[3.1.0] systems.

The four-component Hantzsch reaction provides access to pharmaceutically important dihydropyridines. To expand the utility of this method, we have developed a route under organocatalytic conditions with good yields and excellent ee's. Through catalyst screening, we found that a BINOL-phosphoric acid allowed enantioselective synthesis of six-membered heterocycles with a variety of substitution p...

A metal-free protocol for the synthesis of substituted 1,6-dihydropyridines with quaternary stereogenic centers via a cascade aza-Wittig/6?-electrocyclization process has been developed. The high functional group compatibility and broad scope this method were demonstrated by using wide range easily available vinyliminophosphoranes ketones, yields up to 97%. modification obtained products allowe...

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.

A Ni/photoredox dual catalytic cross-coupling is disclosed in which a diverse range of (hetero)aryl bromides are used as electrophiles, with 1,4-dihydropyridines serving as precursors to Csp3-centered alkyl radical coupling partners. The reported method is characterized by its extremely mild reaction conditions, enabling access to underexplored cores.

A new calcium blocker, designated leualacin, has been isolated from Hapsidospora irregularis. The compound inhibits the binding of 3H-nitrendipine, a well known synthetic calcium blocker, to cardiac Ca channel in a competitive manner, although its structure is completely different from dihydropyridines.