A series of pyrano-fused pyrazolo[3,4-b]pyridine derivatives with an aryl group presenting the 2-position of the pyridine nucleus have been synthesized by microwave-assisted three-component reactions of aldehydes, tetrahydropyran-4-one, and 3-methyl-1-phenyl-1H-pyrazol-5-amine in HOAc. This method is very efficient because of short reaction times and easy work-up, and it provides an efficient and promising synthetic strategy for the construction of the tricyclic pyrano-fused pyrazolo[3,4-b]pyridine skeleton.

A green and highly efficient method for the synthesis of polyfunctionalized indoline-spiro fused pyran derivatives has been established. This reaction was conducted by reacting readily available and inexpensive starting materials, such as isatins, cyclic-1,3-dicarbonyl compounds, and malononitrile in aqueous media without any catalysts under microwave irradiation. The present green synthesis shows fascinating properties such as the use of water as the reaction solution, concise one-pot conditions, short reaction periods (8–14 min), and easy purifications. The synthesis could also set a good example to GAP (Group-Assistant-Purification) chemistry in which purification via chromatography can be avoided and the pure products can be easily acquired only by washing the crude products with 95% EtOH.

An efficient dimedone-catalyzed synthesis of highly functionalized thiazol-2-yl substituted E-acrylonitrile derivatives has been established through two-step reaction of α-thiocyanate ketones with malononitrile and amines. The α-thiocyanate ketones were subjected with malononitrile to provide thiazol-2-ylidenemalononitrile derivatives, followed with various amines in the present of dimedone to yield the final thiazol-2-yl substituted acrylonitrile derivatives.

A tandem one-pot synthesis of polysubstituted 1,3-thiazines has been developed by reacting with cyanoacetamide and isothiocyanate derivatives to give rise to 2-cyano-3-mercaptoacrylamides, which are trapped in situ by various aldehydes or diversely substituted ketones through intermolecular cyclization, providing polysubstituted 1,3-thiazine derivatives in short reaction times with good to excellent yields. The salient features of this novel protocol are operational simplicity, accessing the desired products from the readily available starting materials and easy of product isolation and may find wide spread applications in medicinal chemistry.