A base-promoted one-pot three-component domino reaction of in situ generated pyridinium ylides with α-oxoketene dithioacetals (AKDTAs) lead to synthesis of indolizine derivatives. In this one-pot transformation, three new bonds and one new ring was efficiently formed in one sequence. The current method provides a simple, convenient route for the synthesis of biologically important indolizine derivatives without using any catalyst in good yield. The synthesized compound 4 g was confirmed by single crystal X-ray analysis.[a] V.

A one-pot, five component domino synthesis of novel thioether containing dihydropyrano[2,3-c]pyrazoles under solvent-free and catalyst-free conditions is demonstrated.

A one‐pot synthesis of 3,4‐dihydro‐2H‐pyran derivatives has been achieved using substituted styrenes, aqueous formaldehyde and various β‐keto esters. This multicomponent protocol employs erbium (III) triflate as a catalyst affording 3,4‐dihydro‐2H‐pyran derivatives in good to excellent yields (72‐98%). Furthermore, synthesis of the bicyclic fused ring system such as 2‐aryl‐2,3,4,6,7,8‐hexahydro‐5H‐pyrano[2, 3‐d]pyridazin‐5‐one 6 was achieved from the corresponding 3,4‐dihydro‐2H‐pyran 4.

Keywords:Dimethyl phthalate, one-pot synthesis, green synthesis and water; 2H-indazolo[2,1-b]phthalazine-trione derivatives Water mediated one-pot, four-component synthesis of substituted 2H-indazolo[2,1-b]phthalazine-triones from dimethyl phthalate, hydrazine, dimedone and aromatic aldehydes have been reported in the presence of p-toluenesulfonic acid (PTSA) as catalyst at 100 °C for 1.5-2.0 h. This methodology offers several advantages such as good yields, short reaction time, simple procedure, mild condition and environmentally begins. * Corresponding Authors