A novel method for the metal-free synthesis of amides from thioamides based on visible-light photoredox catalysis and in an air atmosphere is reported. Natural pigment chlorophyll is used as a photosensitizer to generate singlet molecular oxygen 1O2, which is involved in the aerobic desulfurization of thioamides. The protocol provides amides in good yields at room temperature under mild conditions
报道了一种基于可见光光氧化还原催化和空气气氛的硫代酰胺无金属合成酰胺的新方法。天然色素叶绿素作为光敏剂产生单线态分子氧1 O 2,参与硫代酰胺的好氧脱硫。该协议在温和条件下在室温下以良好的收率提供酰胺。在实验结果的基础上,提出了一种合理的光氧化还原机制。
Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
Ortho effects in organic molecules on electron impact: XI—the interestingortho effect of the methoxy group ino-methoxy aromatic thioamides
作者:D. V. Ramana、S. K. Viswanadham
DOI:10.1002/oms.1210181003
日期:1983.10
AbstractIt has been noticed that the major part of the loss of ṠH from the molecular ion of most of the o‐methoxythioamides results from an ortho effect of the methoxy group. Comparison of the MIKE spectra of the [MSH]+ of 1‐(2‐methoxyphenylthioxomethyl)piperidine and 1‐(2‐methoxyphenylthioxomethyl)pyrrolidine with the MIKE spectra of [MSH]+ of the corresponding unsubstituted compounds, reported earlier, indicated two parallel pathways for the formation of [MSH]+ in the o‐methoxy compounds. In the first pathway, as has been noticed in thioamides in general, the loss of ṠH involves the migration of either the α‐hydrogen in the amine moiety or the hydrogen attached to nitrogen. In the second pathway, the migration of a hydrogen from the o‐methoxy group to the sulphur atom followed by ejection of SH from the molecular ion leads to a stable cyclized ion. Interesting secondary fragmentations as a consequence of this ortho effect have also been noticed.