A Facile One-Pot and Green Multi-Component Synthesis of 2-Amino-4Hpyrans Promoted by Pyridinium p-Toluenesulfonate in Aqueous Medium

Graphene oxide supported ionic liquid/Fe complex: a robust and highly stable nanocatalyst

“…To date, tetrahydrobenzo[b]pyrans have been prepared through several developed methods. [25][26][27][28] However, various limitations are associated with these methods, such as high catalyst loading, low yields, the use of expensive ligands, tedious work-ups, difficult separation of product and catalyst, and the use of hazardous solvents. Thus, it is highly required to develop an environmentally-friendly, highly efficient, simple and affordable method for the synthesis of tetrahydrobenzo[b] pyrans.…”

Fe3O4@RB@LDH: Efficient and Recyclable Photocatalyst Visible‐Light Mediated Synthesis of Pyran and Pyrrolidinone Derivatives and Their Anti‐Microbial Activities

“…Therefore, good efforts have been made by chemists for the synthesis of these heterocyclic scaffolds using numerous methodologies. A number of methods have been reported for the synthesis of pyran detivatives involving the multicomponent condensation of aldehydes, malononitrile and 1,3 cyclic diketones or substituted pyrazoles in presence of various catalysts such as (NH 4 ) 2 HPO 4 , [22] Na 2 SeO 4 , [23] CeCl 2 .7H 2 O, [24] SiO 2 @Pr@SO 3 H, [25] Cl 3 COOOH, [26] sodium acetate, [27] PFPA, [28] Fe 2 O 3 @SiO 2 @VB 1 NPs, [29] molecular iodine, [30] LiBr, [31] pyridinium p-toluenesulfonate, [32] NaF, [33] etc. In spite of the advantages of these synthetic methods, quite a few of them have some limitations such as harmful conditions, expensive catalyst, low yields, long reaction times, high temperature, difficult workup procedure etc.…”