This work describes a fast, mild, convenient and simple method for preparing of nitrogen heterocyclic derivatives by MCR reaction under solvent-free condition.

Benzo[a]quinolizine-2-one derivatives are readily assembled from 1,2,3,4-tetrahydroisoquinoline and β-ketoaldehydes by means of a new intramolecular redox-Mannich process. These reactions are promoted by simple acetic acid and are thought to involve azomethine ylides as reactive intermediates.

Forging the lock that autolocks! Rh-NHC catalysts promote a new access to 4 H-quinolizine species from 2-vinylpyridine and terminal and internal alkynes through C-H activation and C-C coupling reactions (see figure). N-Bridgehead heterocycle formation is favored for internal- over terminal-substituted butadienylpyridine derivatives in a thermal 6π-electrocyclization process.

An activatable BODIPY probe for in vitro detection and fluorescence cell imaging of free Mg2+ without interference from Ca2+ is described. Fluorescence amplification of the probe is observed upon detection of physiological concentrations of Mg2+ due to reduced rotation of the fluorophore and effective chelation by a quinolizine-based core.

In this paper the absorption and luminescence properties of some heterocycles incorporating the quinolizine [1] or indolizine [2] ring system are studied. The investigated compounds 1 [3], 2 a b [4], 3 [4], 4 a b [5], 5 [5] and 6 a c [6] are shown in Figure 1. There are no data in the literature on their luminescence properties. Quantum chemical investigations have been performed to elucidate w...

A novel and efficient cascade annulation of tertiary α-hydroxy ketones and dimethyl but-2-ynedioate is reported. The reaction, which only requires a base as the promoter, provides a straightforward access to polysubstituted pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones under very mild reaction conditions.

4-Oxo-4H-quinolizine-3-carboxylic acid derivatives bearing sulfamido, carboxylamido, benzimidazole and benzothiazole substituents have been designed and synthesized. The structures of these new compounds were confirmed by (1)H-NMR, (13)C- NMR, IR and ESI (or HRMS) spectra. Compounds were screened for possible HIV integrase inhibitory activity.

Pingbeimunone A (1), a new compound, together with the known ussuriedine (2), benzo[7,8]fluoreno[2,1-b]quinolizine cevane-3,6,16,20-tetrol (3), ebeiedinone (4), pingbeimine C (5) and verticine (6) were isolated from Fritillaria ussuriensis. The structure was elucidated on the basis of spectral analysis (IR, NMR and MS spectroscopy). In addition, their AChE inhibitory activities were also tested.