Tertiary Amines as Synthetic Equivalents of Vinyl Cations: Zinc Bromide Promoted Coupling of Propargylamines with α-Isocyanoacetamides To Give 2,4,5-Trisubstituted Oxazoles Initiated by an Internal Redox Process
作者:Yann Odabachian、Qian Wang、Jieping Zhu
DOI:10.1002/chem.201302106
日期:2013.9.9
Crabée interrupted: Propargylamines 1 react with α-isocyanoacetamides 2 in the presence of zinc bromide to afford vinyl oxazoles 3. The transformation, wherein the propargylamine acts as a vinyl cation syntheticequivalent, involves a domino sequence incorporating a 1,5-hydride shift, intermolecular trapping/cyclization, and a 1,6-elimination (see scheme).
order to investigate the isotope effect on the microsomal oxidative deamination of cyclohexylamine, alpha-deuterium(D)-labelled cyclohexylamine was synthesized. The deuterium labelling was found exclusively at the alpha-position with a purity of greater than 99 atom percent. Metabolic studies in vitro indicate that a significant deuterium isotope effect operates in the oxidative deamination of alpha-D-labelled
A novel metal-free photochemical method for the deconstructive carboxylation of alkenes with CO2 is reported for the first time. The power of this strategy is demonstrated for the late-stage carboxylation of bioactive molecule derivatives and the synthesis of propionate nonsteroidal anti-inflammatory drugs.
Effect of Hyperconjugation on the Decomposition of<i>N</i>-Alkyl-<i>N</i>-nitrosoacetamide
作者:Masuo Murakami、Katsuhiko Akagi、Yonosuke Mori
DOI:10.1246/bcsj.35.11
日期:1962.1
Regioselective Ring Expansion of 2,4-Diiminoazetidines via Cleavage of C–N and C(sp<sup>3</sup>)–H Bonds: Efficient Construction of 2,3-Dihydropyrimidinesulfonamides
作者:Yang Wang、Yue Chi、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1021/ja211486f
日期:2012.2.15
A highly regioselective base-mediated ring expansion of 2,4-diiminoazetidines via cleavage of C-N and C(sp(3))-H bonds is achieved for the first time to afford efficiently 2,3-dihydropyrimidinesulfonamides. The mechanism of the ring expansion via tandem 4 pi electrocyclic ring-opening/1,5-H shift/6 pi electrocydic ring-closing is well confirmed by the trapping experiments of two key intermediates and deuterium labeling studies.