Lewis acid-catalyzed reactions in protic media. Lanthanide-catalyzed reactions of indoles with aldehydes or ketones
作者:Depu Chen、Libing Yu、Peng George Wang
DOI:10.1016/0040-4039(96)00958-6
日期:1996.6
Lanthanide triflates were found to be effective catalysts for reactions of indoles with aldehydes or ketones in aqueous solution.
发现镧系三氟甲磺酸酯是吲哚与水溶液中的醛或酮反应的有效催化剂。
Hydrated ferric sulfate-catalyzed reactions of indole with aldehydes, ketones, cyclic ketones, and chromanones: Synthesis of bisindoles and trisindoles
作者:Wayland E. Noland、Honnaiah Vijay Kumar、Grant C. Flick、Cole L. Aspros、Jong Hyeon Yoon、Andre C. Wilt、Nasim Dehkordi、Sheng Thao、Andrew K. Schneerer、Siming Gao、Kenneth J. Tritch
DOI:10.1016/j.tet.2017.05.061
日期:2017.7
Hydrated ferric sulfate [Fe2(SO4)3·xH2O] has been found to be an efficient catalyst for condensation of bisindoles or trisindoles with aliphatic or aryl aldehydes and ketones including methyl and ethyl-alkyl ketones, methyl aryl ketones, cyclic ketones, and 4-chromanones in 19–96% yields. Trisindoles and 2,2'-alkylidenebisindoles were obtained from indole-3-carbaldehydes or 3-methylindole in 72–84% yields
水合硫酸铁[Fe 2(SO 4)3 · x H 2 O]被发现是双吲哚或三吲哚与脂族或芳基醛和酮(包括甲基和乙基烷基酮,甲基芳基酮)缩合的有效催化剂,环酮和4-chromanones的产率为19-96%。从吲哚-3-甲醛或3-甲基吲哚获得三吲哚和2,2'-亚烷基双吲哚,产率为72–84%。总共使用了43种底物,得到33种双吲哚,3种三吲哚和一种2:2产物。其中有十七个是新的。用Fe 2(SO 4)3 · x加热乙醇悬浮液可获得最佳结果。H 2 O负载量为60 mg / mmol亲电试剂。反应时间通常为1-4小时,而受阻亲电试剂则需要8-24小时。这些条件足够强以促进吲哚与底物的2:1缩合,而不会形成高阶副产物,几乎没有例外。该策略的特征在于催化剂对各种官能团的耐受性,易于获得的起始原料,简单的操作,温和的反应条件以及对环境友好。
PEG-SO<sub>3</sub>H as a Catalyst for the Preparation of Bis-Indolyl and Tris-Indolyl Methanes in Aqueous Media
作者:V. Jhansi Rani、K. Veena Vani、C. Venkata Rao
DOI:10.1080/00397911.2010.551700
日期:2012.7.15
Abstract A facile, efficient, and green synthesis of bis-indolyl and tris-indolyl methanes has been developed by one-pot condensation of indole with structurally diverse aldehydes and ketones in the presence of poly(ethylene glycol)–bound sulfonicacid as catalyst at room temperature. GRAPHICAL ABSTRACT
introduces a Pd(II)/LA-catalyzed (LA: Lewis acid) decarboxylative addition reaction for the synthesis of bis(indolyl)methanederivatives. The presence of Lewis acid such as Sc(OTf)3 triggered Pd(II)-catalyzed decarboxylative addition of propiolic acids with indoles to offer the bis(indolyl)methanederivatives in moderate to good yields, whereas neither Pd(II) nor Lewis acid alone was active for this synthesis