Friedel-Crafts Alkylation of Indoles with Nitroalkenes Catalyzed by Zn(II)-Thiourea Complex
作者:Ningning Wan、Yonghai Hui、Zhengfeng Xie、Jide Wang
DOI:10.1002/cjoc.201180480
日期:2012.2
Friedel‐Craftsalkylation of indoles with nitroalkenes catalyzed by a novel Zn(II)‐thiourea complex has been developed. The remarkable advantages of this reaction are mild reaction conditions, simple workup procedure, high yield of products and the use of ethanol as acceptable solvent.
mind, we report a catalytic Friedel‒Crafts alkylation method catalyzed by a charged thiourea incorporating a cationic cyclopropenium moiety. Mechanistic studies, including density functional theory computational calculations, variable time normalization analysis, and 1H NMR binding studies, collectively reveal this charged-enhanced reactivity proceeds by a dual hydrogen bond-mediated LUMO-lowering
Quantification of Catalytic Activity for Electrostatically Enhanced Thioureas via Reaction Kinetics and UV–vis Spectroscopic Measurement
作者:Yang Fan、Curtis Payne、Steven R. Kass
DOI:10.1021/acs.joc.8b01552
日期:2018.9.21
Charged thiourea derivatives containing one and two methylated or octylated pyridinium ion centers and a tetraarylborate or triflate counteranion are reported. These novel catalysts are much more active in the Friedel–Crafts reactions of trans-β-nitroalkenes with N-methylindoles than the privileged N,N′-bis(3,5-bis(trifluoromethyl)phenyl)thiourea (i.e., Schreiner’s thiourea) by up to 2–3 orders of
and facile visible-light-mediated alkylation of indoles and nitroalkenes has been developed. In this protocol, rose bengal acts as a photosensitizer, and environmentally benign water was used as the green and efficient reaction medium. Indoles reacted smoothly with nitroalkenes under the irradiation of visible-light and generated corresponding 3-(2-nitroalkyl)indoles in moderate to good yields (up to
ABSTRACT An efficient and environmentally friendly protocol has been demonstrated for water-soluble (salicyladimine)2Cu complex-catalyzed Michaeladdition of indoles to nitroolefins in water at 30 °C. A variety of substituted indoles and β-nitrostyrenes could be worked well to provide the title products in 81–97% yields. Moreover, the catalyst can be reused directly at least for four times without
摘要 在 30 °C 下,水溶性(水杨酸二亚胺)2Cu 络合物催化吲哚与硝基烯烃迈克尔加成反应是一种高效且环保的方案。各种取代的吲哚和 β-硝基苯乙烯可以很好地工作,以 81-97% 的产率提供标题产品。此外,催化剂可以直接重复使用至少四次,而不会显着降低活性。图形概要