The reductive singleelectrontransfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon–hydrogen (C–H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features
α‐Diazo Sulfonium Triflates: Synthesis, Structure, and Application to the Synthesis of 1‐(Dialkylamino)‐1,2,3‐triazoles
作者:Xiangdong Li、Christopher Golz、Manuel Alcarazo
DOI:10.1002/anie.202014775
日期:2021.3.22
of a series of sulfonium salts containing transferable diazomethyl groups is described, and the structure of these compounds is elucidated by X‐ray crystallography. Under photochemical conditions, reaction of these salts with N,N‐dialkyl hydrazones affords 1‐(dialkylamino)‐1,2,3‐triazoles via diazomethyl radical addition to the azomethine carbon followed by intramolecular ring closure. The straightforward
描述了一系列含有可转移重氮甲基的锍盐的一锅法合成,并通过 X 射线晶体学阐明了这些化合物的结构。在光化学条件下,这些盐与N , N -二烷基腙反应,通过重氮甲基自由基加成到偶氮甲碱碳上,然后进行分子内闭环,得到 1-(二烷基氨基)-1,2,3-三唑。还报道了由此获得的结构直接转变为介离子卡宾-金属配合物,并表征了这些新配体的供体性质。
Visible Light‐Induced [3+2] Cyclization Reactions of Hydrazones with Hypervalent Iodine Diazo Reagents for the Synthesis of 1‐Amino‐1,2,3‐Triazoles
作者:Jun‐Ying Dong、He Wang、Shukuan Mao、Xin Wang、Ming‐Dong Zhou、Lei Li
DOI:10.1002/adsc.202001436
日期:2021.4.13
In this study, visible‐light‐induced [3+2] cyclization reactions of hydrazones with hypervalent iodine diazo reagents as diazomethyl radical precursors are reported. Mild reaction conditions, a broad substrate scope, and excellent functional group compatibility were observed. Furthermore, the synthetic utility was demonstrated by gram‐scale synthesis and elaboration to several value‐added products
A simple and highly efficient method for the oxo-sulfonylation of aldehyde-derived hydrazones has been developed using sulfinic acid as a source of sulfonyl group and oxygen as a green oxidant under metal-free conditions at room temperature. The present C–O and N–S bond-forming difunctionalization strategy affords diversely functionalized N-acylsulfonamides in good yield. Experimental results suggest
Electrochemical synthesis of tetrazoles <i>via</i> metal- and oxidant-free [3 + 2] cycloaddition of azides with hydrazones
作者:Zenghui Ye、Feng Wang、Yong Li、Fengzhi Zhang
DOI:10.1039/c8gc02889c
日期:——
An unprecedented electrochemical [3 + 2] cycloaddition reaction for the synthesis of valuable tetrazoles was developed. Readily available azides and hydrazones were used as the starting materials under simple metal- and oxidant-free reaction conditions. Various functional groups are compatible with this green protocol which can be carried out on a gram-scale or in one pot easily.