Base‐Promoted Regiospecific Synthesis of Fully Substituted 1,2,3‐Triazoles and 1,5‐Disubstituted 1,2,3‐Triazoles

Abstract

An efficient strategy have been developed for the synthesis of fully substituted 1,2,3-triazoles and 1,5-disubstituted 1,2,3-triazoles subsequently by CÀ C bond cleavage. Regitz diazo-transfer and CÀ C bond cleavage process were involved in this reaction to give 1,2,3-triazoles with good substrate tolerance. This protocol provideed a facile and an expeditious approach for the assembly of diversely structural 1,2,3-triazoles.

Organocatalyzed Regioselective Synthesis of 1,5‐Disubstituted 1,2,3‐Triazolyl Glycoconjugates

“…The cycloaddition at a lower concentration of the catalyst T1-T3 resulted in satisfactory yields (10-60 %) of 3 a (Table 1, entries 2-6). Further screening of catalyst T4-T6 in term of longer reaction time and temperature dependency were checked and results suggested no significant change in yields (Table 1, entries [14][15][16][17][18]. It was noticed that the formation of 1,4-disubstitued triazole 4 a marginally increased when the reaction was performed in dry DMF solvent (Table 1, entries 19,20).…”

“…[12,13] Zhang et al have reported a two-step synthesis of 1,5disubstituted 1,2,3-triazoles by employing substituted amines and propynones to generate ketoamine, followed by treatment with tosyl azide gave the desired triazoles (Scheme 1b). [14] Earlier, thiourea-based catalytic system were used in azidealkye cycloaddition reaction to afford 1,4-disubstituted triazoles. For example, Nembenna et al used thiourea supported Cucatalyst for the azide-alkyne cycloaddition reaction to furnish high yield of regioselective 1,4-disubstituted triazoles.…”

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.…”