Novel Alternative for the N<i>−</i>N Bond Formation through a PIFA-Mediated Oxidative Cyclization and Its Application to the Synthesis of Indazol-3-ones
The synthesis of a series of N,N‘-disubstituted indazolone derivatives starting from methyl anthranilates is presented. This general approach features a novel and easy way for access to the target N-heterocycles by formation of a new N−N single bond. The key cyclization step embraces the formation of an N-acylnitrenium intermediate, mediated by the hypervalent iodine reagent PIFA, and its succeeding
IBX-mediated synthesis of indazolone via oxidative N–N bond formation and unexpected formation of quinazolin-4-one: in situ generation of formaldehyde from dimethoxyethane
作者:Sang Won Park、Hoon Choi、Jung-hun Lee、Yeon-Ju Lee、Jin-Mo Ku、Sang Yeul Lee、Tae-gyu Nam
DOI:10.1007/s12272-016-0706-z
日期:2016.3
with no electron-rich phenyl substituted amides afforded the unanticipated quinazolin-4-ones in moderate yields, which were not formed in DCE solvent. The formation of quinazolin-4-ones was attributed to the in situ generation of formaldehyde from DME. Therefore, the reaction might undergo different pathway in DME when the substrate aryl amides have phenyl rings without electron donating substituents
transformations are based on the fact that DMF can serve as a reaction solvent and one carbon synthon for the construction of heterocyclic rings. Moreover, this protocol features base-free and Brønsted acid free environmentally benign conditions with broad synthetic scope. A good scalability is demonstrated.
Palladium-Catalyzed <i>Ortho</i>-Selective C–H Oxidative Carbonylation of <i>N</i>-Substituted Anilines with CO and Primary Amines for the Synthesis of <i>o</i>-Aminobenzamides
An efficient, one-pot strategy with high selectivity and high atom economy for the synthesis of o-aminobenzamides has been developed via palladium-catalyzed ortho-selective C–H oxidative carbonylation of N-substitutedanilines with CO and primary amines. A wide range of N-substitutedanilines and primary amines can be tolerated in this transformation to afford the corresponding o-aminobenzamides in
Iodine-Promoted Oxidative Cyclization of Acylated and Alkylated Derivatives from Epoxides toward the Synthesis of Aza Heterocycles
作者:Alageswaran Jayaram、Karthick Govindan、Vijaya Raghavan Kannan、Vijay Thavasianandam Seenivasan、Nian-Qi Chen、Wei-Yu Lin
DOI:10.1021/acs.joc.2c02802
日期:2023.2.3
A new method for directly synthesizing acylated and alkylated quinazoline derivatives by the epoxide ring-opening reaction in the presence of I2/DMSO with 2-aminobenzamide is described herein. The developed mild protocol is efficient and displays a wide variety of functional group tolerance and substrate-controlled high selectivity, and the application of a continuous flow technique allows for faster