Synthesis of fused heterocycles via preferential hydroamination of o-haloarylalkynes over N-arylation and successive intramolecular CC bond formation

Cu-catalyzed transannulation reaction of pyridotriazoles with terminal alkynes under aerobic conditions: efficient synthesis of indolizines

“… 1 This method is based on the ability of pyridotriazole to exist in an equilibrium with diazo-form A , 2 , 3 which can be trapped with Rh( ii ) to form the reactive pyridyl carbene intermediate B , capable of reacting with terminal alkynes 1 a to produce valuable indolizines 3 ( Scheme 1 ). 4 , 5 However, this transannulation reaction has several shortcomings.…”

Synthesis of 1,6‐Naphthyridine and Its Derivatives: A Systematic Review

“…[29] The strong base, LDA, abstracts the protons from the methyl group in addition to the abstraction of a proton from the carboxylic acid of 2-methylnicotinic acid derivatives. The resultant dianion intermediate (45) subsequently reacted with the available aryl nitrile or alkyl nitrile and afforded the cyclized products, 6H- [1,6]naphthyridin-5-ones (46) in moderate yields.…”

Recent Studies of Bifunctionalization of Simple Indoles

“…The use of indole NH in annulation typically required a base to improve nucleophilic property. As shown in Scheme 27, adducts from addition to unsaturated bonds, [25a–c] could trigger a tandem cyclization to yield nitrogen containing cyclic compounds. The mechanism involved preferential N‐ arylation and intramolecular attack of C2 position.…”

“…The mechanism involved preferential N‐ arylation and intramolecular attack of C2 position. For example, the Verma group [25b] utilized o‐ halo arylalkynes for the synthesis of fused heterocycles. t BuOK promoted the regioselective addition of N atom.…”