开发了光催化和光诱导硅基自由基级联环化程序,用于从 2-芳基-N-丙烯酰吲哚与氢硅烷绿色、简单地制备稠合四环骨架硅烷化吲哚并[2,1- a ]异喹啉-6(5 H )-酮。该光催化反应以9,10-二氰基蒽(DCA)作为有机光催化剂和3-乙酰氧基奎宁环作为氢原子转移(HAT)催化剂在室温、无金属和氧化剂的条件下进行。光氧化还原催化转化成功的关键包括 (1) DCA* [ E 1/2 (*P/P – ) = +1.97 V vs. SCE in MeCN] 通过 3-乙酰氧基奎宁环 ( E p = +1.22 V vs. MeCN 中的 SCE),以及(2)通过亲电 N +•从氢 Si-H 键中夺取氢原子的热力学可行性。特别是,在可见光照射下通过电子供体受体(EDA)复合物利用(TMS)3 SiH与2-芳基-N-丙烯酰吲哚进行简单的光诱导级联环化。
Rh-Catalyzed oxidative C–H activation/annulation: converting anilines to indoles using molecular oxygen as the sole oxidant
作者:Guoying Zhang、Hui Yu、Guiping Qin、Hanmin Huang
DOI:10.1039/c3cc49751h
日期:——
A practical and efficient Rh(III)-catalyzed aerobic C-Hactivation has been developed for the facile synthesis of a broad range of indoles from simple anilines and alkynes. The protocol could be conducted under mild conditions and used environmentally friendly oxygen as the sole clear oxidant.
Synthesis of Unprotected and Highly Substituted Indoles by the Ruthenium(II)-Catalyzed Reaction of Phenyl Isocyanates with Diaryl/Diheteroaryl Alkynes/Ethyl-3-phenyl Propiolates
作者:Amrendra Kumar、Narender Tadigoppula
DOI:10.1021/acs.orglett.0c02793
日期:2021.1.1
unprotected and highly substituted indoles by an in situ installed carbamide-directed Ru(II)-catalyzed intermolecular oxidative annulation of phenyl isocyanates with diaryl/diheteroaryl alkynes/ethyl phenyl propiolates in the presence of Cu(OAc)2·H2O as an oxidant and AgSbF6 as an additive at 120 °C within 3 h.
A redox‐neutral cobalt(III)‐catalyzed synthetic approach for the direct synthesis of unprotected indoles showcasing an N−Nbondcleavage is reported. The herein newly introduced Boc‐protected hydrazines establish a beneficial addition to the limited portfolio of oxidizing directing groups for cobalt(III) catalysis. Moreover, the developed catalytic methodology tolerates a good variety of functional
A visible-light-induced radical-cascade selenocyanation/cyclization of N-alkyl-N-methacryloyl benzamides, 2-aryl-N-acryloyl indoles, and N-methacryloyl-2-phenylbenzimidazoles with potassium isoselenocyanate (KSeCN) was developed. The reactions were carried out with inexpensive KSeCN as a selenocyanation reagent, potassium persulfate as an oxidant, 2,4,6-triphenylpyrylium tetrafluoroborate as a bifunctional
开发了一种可见光诱导的N-烷基-N-甲基丙烯酰基苯甲酰胺、2-芳基-N-丙烯酰基吲哚和N-甲基丙烯酰基-2-苯基苯并咪唑与异硒氰酸钾 (KSeCN) 的自由基级联硒氰化/环化反应。该反应以廉价的KSeCN作为硒氰化试剂,过硫酸钾作为氧化剂,2,4,6-三苯基吡咯鎓四氟硼酸盐作为相转移催化和光催化的双功能催化剂进行。含硒氰酸盐的异喹啉-1,3(2 H ,4 H )-二酮、吲哚并[2,1 -a ]异喹啉-6(5 H )-酮和苯并咪唑并[2,1- a ]异喹啉-的库6(5 H )-在室温、可见光和环境条件下以中等至优异的产率获得。重要的是,该方案具有反应条件温和、大规模合成、操作简单、产物衍生化、良好的官能团和杂环耐受性等特点。