An Electrophilic Bromine Redox Catalysis for the Synthesis of Indole Alkaloid Building Blocks by Selective Aliphatic C−H Amination
作者:Julien Bergès、Belén García、Kilian Muñiz
DOI:10.1002/anie.201808939
日期:2018.11.26
A new homogeneous bromine(−I/I) redox catalysis is described, which is based on monomeric bromine(I) compounds containing transferable phthalimidato groups. These catalysts enable intermolecular C−H amination reactions at previously unaccessible aliphatic positions and thus enlarge the synthetic potential of direct C−N bond formation, including its application in the synthesis of alkaloid building
One-pot, three-component Fischer indolisation–<i>N</i>-alkylation for rapid synthesis of 1,2,3-trisubstituted indoles
作者:Christopher A. Hughes-Whiffing、Alexis Perry
DOI:10.1039/d0ob02185g
日期:——
A one-pot, three-component protocol for the synthesis of 1,2,3-trisubstituted indoles has been developed, based upon a Fischer indolisation–indole N-alkylation sequence. This procedure is very rapid (total reaction time under 30 minutes), operationally straightforward, generally high yielding and draws upon readily available building blocks (aryl hydrazines, ketones, alkyl halides) to generate densely
Harnessing the Polarizability of Conjugated Alkynes toward [2 + 2] Cycloaddition, Alkenylation, and Ring Expansion of Indoles
作者:Tapas R. Pradhan、Hong Won Kim、Jin Kyoon Park
DOI:10.1021/acs.orglett.8b02230
日期:2018.9.7
Reported is the utilization of electronically biased conjugated alkynes in the development of highly diastereo- and regioselective dearomative [2 + 2] cycloadditions, alkenylations, and ring expansions of electron-rich indoles. Regioselective protonations of cross- and linear-conjugated alkynes were found to be crucial for accessing various cyclobutene-fused indoline and alkenylated indole derivatives
据报道,在高度非对映和区域选择性脱芳香性[2 + 2]环加成,烯基化和富电子吲哚的环扩展中,利用电子偏置的共轭炔烃。发现交叉和线性共轭炔的区域选择性质子化对于获得各种环丁烯稠合的二氢吲哚和烯基化的吲哚衍生物至关重要。此外,由炔酮成功合成的[2 + 2]酮加合物的容易的环扩展提供了1 H-苯并[ b ]氮杂骨架。
Iodine-Catalyzed C–H Amidation and Imination at the 2α-Position of 2,3-Disubstituted Indoles with Chloramine Salts
作者:Xiaozu Liu、Yuxiang Zhou、Zhongqin Yang、Qin Li、Liang Zhao、Peijun Liu
DOI:10.1021/acs.joc.8b00286
日期:2018.4.20
A novel iodine-catalyzed amidation and imination at the 2α-position of 2,3-disubstituted indoles in the presence of chloramine salts with high regioselectivity has been achieved. The protocol is applicable to a wide range of substrates to deliver the corresponding 2α-nitrogen-containing indole derivatives. Furthermore, to demonstrate the synthetic value of this established transformation, a concise
Metal and Oxidant Free Construction of Substituted‐ and/or Polycyclic Indoles: A Useful Alternative to Bischler and Related Syntheses
作者:Giacomo Mari、Lucia De Crescentini、Gianfranco Favi、Stefania Santeusanio、Fabio Mantellini
DOI:10.1002/ejoc.202000845
日期:2020.9.7
wide range of substitutedindoles, including complex polycyclic‐architectures were easily assembled by means of a Amberlyst 15H catalyzed synthesis that employs 1,2‐diaza‐1,3‐dienes and anilines. The metal and oxidant free methodology proposed here is characterized by good yields, total and predictable regioselectivity, and the ability to provide electron withdrawing substitutedindoles.