MeOTf-Mediated Alkynylation of Selenoamides Leading to β-Methylselenenyl α,β-Unsaturated Ketones and Their Characterization
作者:Toshiaki Murai、Yuichiro Mutoh、Shinzi Kato
DOI:10.1021/ol015968u
日期:2001.6.1
[reaction: see text] beta-Methylselenenyl alpha,beta-unsaturatedketones were effectively synthesized by treating selenoamides with methyl triflate, followed by reaction with lithium acetylides. The reaction proceeded with high stereoselectivity to give exclusively Z-isomers. (77)Se NMR studies and X-ray molecular structure analysis of beta-methylselenenyl alpha,beta-unsaturatedketones suggested that
Telluration of seleno- and chloroiminium salts leading to various telluroamides, and their structure and NMR properties
作者:Yuichiro Mutoh、Toshiaki Murai、Shigeru Yamago
DOI:10.1016/j.jorganchem.2006.03.045
日期:2007.1
The reaction of seleno- and chloroiminium salts with a tellurating agent derived from LiAlH4 and elemental tellurium gave telluro-amides in moderate to good yields. This new synthetic method enabled the isolation of the first aliphatic and secondary telluroamides. The molecular structure of an aromatic telluroamide was successfully revealed for the first time; the length of the C=Te bond in the aromatic telluroamide was the same as that in the telluroformamide-Cr complex, and the aromatic ring and Te=C-N moiety were not planar. Unlike the structure in the solid state, spectroscopic data of telluroamides suggest that there is conjugation between these two planes. The properties of the NMR spectra of a series of chalcogenoamides are also discussed. (c) 2006 Elsevier B.V. All rights reserved.