The ozonation of the O-methyloximes has been investigated. Besides the corresponding ketones, ketone diperoxides, and N-methoxyamides were produced. The stereochemistry of the ketone diperoxides was studied by the NMR technique.
Base-mediated homologative rearrangement of nitrogen–oxygen bonds of <i>N</i>-methyl-<i>N</i>-oxyamides
作者:Monika Malik、Raffaele Senatore、Thierry Langer、Wolfgang Holzer、Vittorio Pace
DOI:10.1039/d3sc03216g
日期:——
controlled basic conditions, the N-methyl group of the same starting materials acts as a competent precursor of the methylene synthon required for the homologation. The logic is levered on the formation of an electrophilic iminium ion (via N–O heterolysis) susceptible to nucleophilic attack by the alkoxide previously expulsed. The procedure documents genuine chemocontrol and flexibility, as judged by the diversity
The imino 1,2-Wittig rearrangement of hydroximates provides a novel method for the construction of 2-hydroxyoxime ethers. Upon treatment with LDA, Z-hydroximates smoothly underwent stereoselective rearrangement to give Z-2-hydroxyoxime ethers in good yield, which were converted into amino alcohols. On the other hand, the rearrangement of E-hydroximates gave a mixture of E- and Z-2-hydroxyoxime ethers. This method was successfully applied to a practical synthesis of cytoxazone. (C) 2004 Elsevier Ltd. All rights reserved.
Ruthenium-Catalyzed C–H Oxygenation on Aryl Weinreb Amides
作者:Fanzhi Yang、Lutz Ackermann
DOI:10.1021/ol303520h
日期:2013.2.1
Versatile ruthenium catalysts enabled unprecedented C–H bond oxygenations of aryl Weinreb amides with ample scope under exceedingly mild reaction conditions, thereby also giving access to valuable ortho-hydroxylated aldehydes. Mechanistic studies provided strong support for a kinetically relevant C–H bond activation.