A one-pot synthesis of 2H-pyrido[1,2-a][1,3,5]triazine-2-selenones from acyl isoselenocyanates and pyridin-2-amine

Functionalized Triazines and Tetrazines: Synthesis and Applications

The molecules possessing triazine and tetrazine moieties belong to a special class of heterocyclic compounds. Both triazines and tetrazines are building blocks and have provided a new dimension to the design of biologically important organic molecules. Several of their derivatives with fine-tuned electronic properties have been identified as multifunctional, adaptable, switchable, remarkably antifungal, anticancer, antiviral, antitumor, cardiotonic, anti-HIV, analgesic, anti-protozoal, etc. The objective of this review is to comprehensively describe the recent developments in synthesis, coordination properties, and various applications of triazine and tetrazine molecules. The rich literature demonstrates various synthetic routes for a variety of triazines and tetrazines through microwave-assisted, solid-phase, metal-based, [4+2] cycloaddition, and multicomponent one-pot reactions. Synthetic approaches contain linear, angular, and fused triazine and tetrazine heterocycles through a combinatorial method. Notably, the triazines and tetrazines undergo a variety of organic transformations, including electrophilic addition, coupling, nucleophilic displacement, and intramolecular cyclization. The mechanistic aspects of these heterocycles are discussed in a detailed way. The bioorthogonal application of these polyazines with various strained alkenes and alkynes provides a new prospect for investigations in chemical biology. This review systematically encapsulates the recent developments and challenges in the synthesis and possible potential applications of various triazine and tetrazine systems.

Synthesis of N-(3-Methyl-4-Phenyl-3H-Selenazol-2-Ylidene)Benzamide Derivatives

A three-component and one-pot reaction between phenacyl bromide and aroyl isoselenocyanates in the presence of methylamine gave N-(3-methyl-4-phenyl-3 H-selenazol-2-ylidene)benzamide derivatives in good yields.

Synthesis of 2-Selanylidene-1,9A-Dihydro-2H-Pyrido[1,2-A]Pyrimidine Derivatives

The reactive intermediate produced in the reaction between pyridines and acetylenic esters was trapped by aryl isoselenocyanates to afford 2-selanylidene-1,9a-dihydro-2H-pyrido[1,2-a]pyrimidine derivatives in good yields.

Synthesis of 5-Aryl-1,3-Dimethyl-7-Selenoxopyrimidino[4,5-d]Pyrimidine-2,4(1H,3H)-Dione

A one-pot method for the synthesis of six novel 5-aryl-1,3-dimethyl-7-selenoxopyrimidino[4,5- d]pyrimidine-2,4(1 H,3 H)-diones in excellent yields at room temperature has been achieved via reaction between potassium selenocyanate and an aroyl chloride followed by the addition of 6-amino- N,N′-dimethyluracil.

Synthesis of 4-aryl-1,3,4a-Triazaphenanthrene-2-Selones via Three-Component Condensation of Quinolin-2-Amine, Potassium Selenocyanate and an Acyl Chloride

A three-component reaction between quinolin-2-amine, potassium selenocyanate and variously substituted benzoyl chlorides in acetone at room temperature provided a simple and efficient one-pot route for the synthesis of six 4-aryl-1,3,4a-triazaphenanthrene-2-selones in good yields.

Synthesis of 1-aryl-2,4,10a-Triazaphenanthrene-3-Selones Via a Three-Component Condensation of Isoquinolin-1-Amine, Potassium Selenocyanate and an Acyl Chloride

A simple, one-pot synthesis of six 1-aryl-2,4,10a-triazaphenanthrene-3-selones has been achieved with moderate to good yields via a three-component condensation of isoquinolin-1-amine, potassium selenocyanate and variously substituted benzoyl chlorides in acetone at room temperature.