Base-mediated 1,3-dipolar cycloaddition of pyridinium bromides with bromoallyl sulfones: a facile access to indolizine scaffolds

An expedient and transition-metal-free synthetic strategy has been developed for the construction of substituted indolizines from a unique combination of pyridinium salts and 2-bromoallyl sulfones. This approach does not compromise with the diverse substitutions on both the pyridinium salts and 2-bromoallyl sulfones. Wide substrate scope, operational simplicity, milder reaction conditions and good to moderate yields are the merits associated with the current approach. Moreover, this method provides two products which are amenable for the generation of a library of key indolizine building blocks.

Indium(III)-catalyzed Aza-Conia-Ene Reaction for the Synthesis of Indolizines

A new indium(III)-catalyzed reaction for the synthesis of a series of indolizine scaffolds has been developed. This methodology was highly efficient, allowing a low catalyst loading of 2 mol % (down to 0.5 mol %) and rendering the products in high yields through a 5-exo-dig aza-Conia-ene reaction. Furthermore, the possibility of incorporating an electrophile into the generated pyrrolidone ring in a one-pot synergistic fashion was demonstrated. Finally, based on experimental observations, a mechanism proposal was outlined.

Palladium-catalyzed C-3 desulfitative arylation of indolizines with sodium arylsulfinates and arylsulfonyl hydrazides

Derivatized indolizines were efficiently prepared by direct C-3 arylation of indolizines using sodium arylsulfinates and arylsulfonyl hydrazides in good yields.

An I2-catalyzed oxidative cyclization for the synthesis of indolizines from aromatic/aliphatic olefins and α-picoline derivatives

A novel I₂-catalyzed intermolecular oxidative tandem cyclization reaction of aromatic/aliphatic olefins and α-picoline derivatives has been achieved for the synthesis of indolizines under metal-free conditions.

A domino green method for the rapid synthesis of novel fused isoquinoline derivatives via Knoevenagel/Michael/cyclization reactions on aqueous media and their photophysical properties

An expedient, eco-friendly and green-protocol has been developed for the synthesis of novel 4-imino-2-aryl-4H-pyrido[2,1-a]isoquinoline-3-carbonitrile derivatives via Knoevenagel/Michael/cyclisation reactions in one pot under catalyst-free conditions on aqueous media.