α,β-Unsaturated thiocarbonyl S-sulfides (thiosulfines). Their generation, intramolecular trapping by a non-activated CC dipolarophile via[5 + 2] cycloaddition and trans-sulfurization ability
α,β-Unsaturated thiocarbonyl S-sulfides (thiosulfines)10 were generated by sulfurization of the thioketones 5 and were intramolecularly trapped as 1,5-dipoles giving 8, whereas, in the presence of Et3N, they were transformed by trans-sulfurization via 1,5 cyclization into the thioketones 13 capable of undergoing the intramolecular hetero-DielsâAlder reaction to give cycloadducts 9.
Visible Light Promoted Chan‐Lam Reaction and Cycloaddition to Prepare Chromeno[4,3‐c]isoxazolidines in One‐Pot Reaction
作者:Jie Zhao、Bing‐Qing Huang、Bin‐Can Zhu、Xiao‐Pan Ma、Dong‐Liang Mo
DOI:10.1002/adsc.202100448
日期:2021.10.5
A variety of chromeno[4,3-c]isoxazolidines were prepared in good yields through visiblelightpromoted Chan-Lam reaction and [3+2] cycloaddition cascade reaction in onepot. Mechanistic studies showed that visiblelightpromoted both Chan-Lam reaction and cycloaddition. The obtained products were converted to various useful chromenone derivatives. Moreover, the reaction was easily performed at gram