Base‐Promoted Cascade C−N and C−C Formation: An Approach to Pyrido[1,2‐a]pyrimidinones from Ynones and 2‐Methylpyrimidin‐4‐ols

Abstract

An efficient base-promoted approach for the synthesis of pyrido[1,2-a]pyrimidinones from ynones and 2methylpyrimidin-4-ols have been developed via the CÀ N and CÀ C formation procedure. Diversely structural pyrido[1,2a]pyrimidinones were afforded in up to 95% yield for 29 examples. This reaction featured with advantages such as practical tandem procedure, wide functional group tolerance and metal-free conditions, which has potential application in synthetic and medicinal chemistry.

Metal-Free Cascade Formation of C–C and C–N Bond for the Construction of 3-Cyano-2-Pyridones with Insecticidal Properties

“…Ricinine [ 60 ] has been reported to exhibit pharmacological activities such as antifertility, antiimplantation, antinociceptive, anticancer, antidiabetic, and insecticidal activities ( Figure 1 A). On the other hand, ynones have emerged as valuable building blocks for the construction of complex heterocyclic rings, such as indole, pyrrole, pyridine, triazole, quinoline, thiazole, pyrimidine, and so on [ 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ]. Recently, Trofimov and co-workers [ 74 ] reported the condensation of acylethynylpyrroles and 2-cyano-N-methylacetamide to form N-methyl-3-cyano-2-pyridones ( Figure 1 B).…”

“…However, considerable disadvantages like the relatively poor functional scopes (only 2 examples of N-methyl-3-cyano-2-pyridone as ricinine analogues) and the deficiency of biological activity assays still exist in this process. Inspired by the aforementioned works and previous reports [ 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 ], our primary aim is to develop an easy and efficacious synthetic strategy for the expeditious assembly of 3-cyano-2-pyridones from the cycloaddition of ynones and 2-cyanoacetamide ( Figure 1 C). Simultaneously, we strive to identify 3-cyano-2-pyridones that serve as ricinine analogues and display potent insecticidal properties.…”