Methylene compounds aminomethylene

Nucleophilic attack at the fully conjugated 1,3,5-triazine usually results in ring cleavage. Thus, active methylene compounds react with 1,3,5-triazine in aminomethylenation reactions. A three-component reaction of cyclopentadiene with 1,3,5-triazine and a secondary amine leads to /V,7V-di substituted pentafulven-6-amines (304) and N2-(6-pentafulvenyl)formamidines (305)... 

Aminomethylenation reactions of active methylene compounds with 1,3,5-triazine have also been described by Kreutzberger et al. <85AP(318)89, 85AP(3l8)82l>. A second equivalent of the active methylene compound can react as the third component to give ==CH—linked heterocycles, e.g. (61) from initial product (60) (Scheme 10) <86AP(319)18). 

The reagent reacts with enolizable active methylene compounds to give tri-methylsilyl ethers (equation I). Nonenolizable active methylene compounds react to form aminomethylene compounds (equation II). ... 

The synthesis of aminomethylene derivatives of open-chain active methylene compounds/ and a synthesis of dienaminones have also been described. 

With tetracyanoethylene the 1-methyl derivative of 63 (R = H) led to compounds of type 226 with diethyl azodicarboxylate, to compounds of type 226 and with diethyl azodicarboxylate, to compounds of type 227.114 The 3-formyl and the 3-aminomethylene group of the pyrido[l,2-a] pyrimidines (222 R = H and 224) underwent condensation with compounds containing an active methylene group.297-299,303 The 3-formyl group has also been reacted with primary amines,285 hydrazines.98,260,285 semicarbazide and thosemicarbazide.98... 

Those 3(2//)-furanones with a methylene group at the 2-position condense with ethyl formate and amines to give aminomethylene derivatives of type 46. In such compounds the heterocyclic ring is easily opened by nucleophiles because the functional grouping is that of a vinylogous ester with amines,... 

The 2-pyridone core structure is present in a wide range of compounds with antibacterial, antifungal, and antitumor activity members of this family also play an important role in Alzheimer s disease. By employing microwave-assisted organic synthesis, efficient conditions have been established for introduction of ami-nomethylene substituents in highly substituted bicyclic 2-pyridones. To incorporate tertiary aminomethylene substituents in the 2-pyridone framework, a microwave-assisted Mannich reaction using preformed imminium salts proved to be effective. Primary amino methylene substituents were introduced via cyanodehalogenation then borane dimethyl sulfide reduction of the afforded nitrile (Scheme 10.36) [78]. Microwave irradiation proved superior to traditional conditions for these transformations. 

New syntheses of enamino-ketones by the ring-opening of isoxazoles with samarium di-iodide and with pentacarbonyliron, by the reaction of 2-alkyl-thiomethyl-3-alkylthioacrylophenones with amines, and by the intramolecular photoarylation of A -[2-(haloaryl)ethyl]-(3-enaminones, of enamino-diketones by the reaction of (3-chlorosulphonic acid chlorides with amines and by amino-methylenation of cyclic (3-dicarbonyl compounds, and of enamino-esters by aminomethylenation of esters and lactones and by the reaction of nitriles with magnesium enolates have been reported. 

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