State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China; School of Chemistry & Pharmaceutical Sciences, Guangxi Normal University , 15 Yu Cai Road, Guilin 541004, China.
J Org Chem. 2017 Jun 16;82(12):6417-6425. doi: 10.1021/acs.joc.7b00620. Epub 2017 May 26.
A copper-catalyzed selective cross-coupling reaction of 3-(hydroxyimino)indolin-2-ones with alkenyl boronic acids to access (E)-N-vinyl oxindole nitrones has been achieved under mild conditions. The studies showed that catalytic copper salt selectively gave mono N-vinylation products, while 2.0 equiv of copper salt provided double N-vinylation products. The control experiments revealed that the carbonyl group in 3-(hydroxyimino)indolin-2-one played important roles on N-vinylation. Furthermore, the prepared N-vinyl oxindole nitrones could be converted to spirooxindoles in good yields under thermal conditions.
铜催化的 3-(羟亚氨基)吲哚啉-2-酮与烯基硼酸的选择性交叉偶联反应在温和条件下实现，可得到(E)-N-乙烯基氧化吲哚硝酮。研究表明，催化铜盐选择性地得到单 N-乙烯基化产物，而 2.0 当量的铜盐提供双 N-乙烯基化产物。控制实验表明，3-(羟亚氨基)吲哚啉-2-酮中的羰基在 N-乙烯基化中起着重要作用。此外，所制备的 N-乙烯基氧化吲哚硝酮在热条件下可以很好地转化为螺[吲哚啉-3,3’-吡咯啉]。
