Palladium-Catalyzed Intramolecular N-Arylation of Heteroarenes: A Novel and Efficient Route to Benzimidazo[1,2-a]quinolines

Simple inorganic base promoted polycyclic construction using mucohalic acid as a C3 synthon: synthesis and AIE probe application of benzo[4,5]imidazo[1,2-a]pyridines

Using mucohalic acid as C3 synthon via a transition metal-free multicomponent reaction, an eco-friendly protocol to synthesize C1-functionalized benzo[4,5]imidazo[1,2-a]pyridines which can be applied as fluorescence probe for picric acid is described.

Stereoselective Synthesis of Hexahydroimidazo[1,2-a]quinolines via SN2-Type Ring-Opening Hydroarylation-Hydroamination Cascade Cyclization of Activated Aziridines with N-Propargylanilines

A novel synthetic approach for the construction of 1,2,3,3a,4,5-hexahydroimidazo[1,2-a]quinolines in good yields (up to 75%) with excellent stereoselectivity (dr up to 94:6, ee up to >99%) under one-pot domino ring-opening cyclization (DROC) conditions has been developed. The DROC protocol proceeds through a Lewis acid catalyzed S_N2-type ring-opening of activated aziridines with N-propargylanilines followed by intramolecular cyclization comprising concomitant hydroarylation and hydroamination steps in a domino fashion.

Practical Synthesis of Benzimidazo[1,2-a]quinolines via Rh(III)-Catalyzed C-H Activation Cascade Reaction from Imidamides and Anthranils

We report a novel and practical one-pot Rh(III)-catalyzed strategy to construct benzimidazo[1,2-a]quinolines from readily available imidamides and anthranils. The cascade reaction proceeds via a C-H amination-cyclization-cyclization process in ionic liquid without any additives and possesses simple operation, moderate-to-high yield, and broad substrate scope features, which will provide the reference for the construction of biologically active fused benzimidazoles.

Straightforward synthesis of photoactive chalcogen functionalized benzimidazo[1,2-a]quinolines

A series of new organochalcogen derivatives of benzimidazo[1,2-a]quinolines were synthesized. Both sulfur and selenium derivatives presented similar photophysical properties with absorption in the UV region and fluorescence emission in the violet-blue.

Efficient total synthesis of neocryptolepine and synthetic access to 6-methylquinindoline from a common intermediate

The total synthesis of neocryptolepine and the synthesis of its non-natural isomer 6-methyl quinindoline were efficiently achieved in a few steps from a common intermediate.

Copper(ii) catalyzed synthesis of novel helical luminescent benzo[4,5]imidazo[1,2-a][1,10]phenanthrolines via an intramolecular C–H amination reaction

Novel helical luminescent benzoimidazophenanthrolines were prepared using a Cu(ii) catalyzed C–H amination reaction.

Multicomponent cascade reaction: dual role of copper in the synthesis of 1,2,3-triazole tethered benzimidazo[1,2-a]quinoline and their photophysical studies

One-pot synthesis of 1,2,3-triazole tethered benzimidazo[1,2-a]quinolines through a multi-component reaction is demonstrated. Overall one C–C bond and three C–N bonds are formed in a single step.

Hypervalent iodine(iii) catalyzed oxidative C–N bond formation in water: synthesis of benzimidazole-fused heterocycles

A diverse array of benzimidazole-fused heterocycles was synthesized by in situ generated hypervalent iodine(iii) catalyzed intramolecular oxidative C–N bond formation in water and under ambient conditions.

Microwave assisted [RuCl2(p-cymene)2]2 catalyzed regioselective endo-tandem cyclization involving imine and alkyne activation: an approach to benzo[4,5]imidazo[2,1-a]pyridine scaffold

A microwave assisted efficient route to the synthesis of benzimidazole fused heterocycles through metal catalyzed endo-cyclization strategy involving imine and alkyne activation has been developed.

Synthesis of aza-fused polycyclic quinolines via double C-H bond activation

Simple but efficient: Aza-fused polycyclic quinolines were efficiently assembled through rhodium(III)-based direct double C-H activation of N-aryl azoles followed by cyclization with alkynes without heteroatom-assisted chelation. Copper(II) acetate, aside from acting as an oxidant, could also play an important role in the C-H activation process.

Skeletal diverse synthesis of N-fused polycyclic heterocycles via the sequence of Ugi-type MCR and CuI-catalyzed coupling/tandem Pictet-Spengler reaction

Several diversity-oriented syntheses of N-fused polycyclic heterocycles have been demonstrated but most of them are based on point diversity within the same library and usually involve time-consuming sequential multistep syntheses, which also suffer from low yields and/or poor precursor scopes. We have developed a new strategy for the syntheses of skeletal diverse N-fused polycyclic compounds via an Ugi-type MCR followed by a CuI-catalyzed coupling reaction or tandem Pictet-Spengler reaction. This two-step sequence provides eight distinct skeleton of fused {6-5-5-6}, {5-5-5-6}, {6-5-6-6}, and {5-5-6-6} ring systems that have applications in medicinal chemistry and chemical genetics too.