Toward versatile methods leading to highly functionalized imidazo[1,2-a]pyridines
摘要:
A convenient and general method of preparation of polyfunctionalized imidazo[1,2-a]pyridines is reported. This methodology involves activation of secondary amides leading to the formation of the corresponding amidines 9. Different activating reagents have been evaluated and the efficiency of PCl5 was illustrated with alkyl functionalized groups. (C) 2012 Elsevier Ltd. All rights reserved.
Rapid and Selective in situ Reduction of Pyridine-N-oxides with Tetrahydroxydiboron
摘要:
Pyridine-N-oxides are often used as reactive precursors in the syntheses of substituted pyridines. Isolation and subsequent reduction of the associated pyridine-N-oxide intermediates can be challenging. We have discovered that tetrahydroxydiboron functions as a mild, versatile, and remarkably selective reducing agent for pyridine-N-oxides and may be used in an in situ fashion, thus obviating the isolation of N-oxide-containing intermediates
N-(pyridine-2-yl)amides in water from ketones and 2-aminopyridine via direct oxidative C–C bond cleavage has been developed. A series of ketones, including more challenging inactive aromaticketones substituted with diverse long-chain alkyl groups, were selectively converted to N-(pyridine-2-yl)amides. Furthermore, the protocol can be applied to aryl alkyl carbinols to afford the corresponding amides in moderate
A One-Pot Copper Catalyzed Biomimetic Route to <i>N</i>-Heterocyclic Amides from Methyl Ketones via Oxidative C–C Bond Cleavage
作者:Parthasarathi Subramanian、Satrajit Indu、Krishna P. Kaliappan
DOI:10.1021/ol5031266
日期:2014.12.5
A direct one-pot Cu-catalyzed biomimetic oxidation of methyl ketones to pharmaceutically important N-heterocyclic amides is reported. The scope of the method is broad, scalable, and mild, and the reaction is tolerant with various acid, base sensitive functionalities with multiple heteroatoms and aryl halides. The extensive mechanistic studies suggest that this reaction follows the Luciferin-Luciferase-like
A mild and green methodology for the construction of N‐(pyridine‐2‐yl)amides from alkylarenes and 2‐aminopyridine in one step was developed. Various alkylarenes were directly transformed into the corresponding N‐(pyridine‐2‐yl)amides through tandem C(sp3)–H bond activation/oxidative cyclization/C–C bondcleavage.
A procedure for the synthesis of N-heteroaryl amides directly from oxidative amidation of aldehydes catalyzed by heteropolyanion-based ionic liquids has been reported. The proposed N-directing dual-catalysis mechanism was briefly investigated.
A facile tandem decyanation/cyanation reaction of α-iminonitriles toward cyano-substituted amides
作者:Zhengwang Chen、Pei Liang、Botao Liu、Haiqing Luo、Jing Zheng、Xiaowei Wen、Tanggao Liu、Min Ye
DOI:10.1039/c8ob02186d
日期:——
A newtandem decyanation/cyanation reaction of α-iminonitriles has been developed. A variety of cyano-substituted aryl amides and heteroaryl amides are synthesized in good yields. Both electron-rich and electron-deficient groups are compatible with the standard conditions. This reaction features a nonmetallic cyano source, tandem decyanation and cyanation reaction, waste utilization of the HCN from