Regioselective Synthesis of Indoles via Reductive Annulation of Nitrosoaromatics with Alkynes
作者:Andrea Penoni、Jerome Volkmann、Kenneth M. Nicholas
DOI:10.1021/ol017139e
日期:2002.3.1
[reaction: see text] Indoles are produced regioselectively and in moderate yields by two new processes: (a) from the [CpRu(CO)2]2-catalyzed reaction of nitrosoaromatics (ArNO) with alkynes under carbon monoxide and (b) in a two-step sequence involving the (uncatalyzed) reaction of ArNO with alkynes, followed by reduction of the intermediate adduct.
Palladium-catalyzed C-H formylation of electron-rich heteroarenes through radical dichloromethylation
作者:Yan Bao、Jian-Yong Wang、Ya-Xuan Zhang、Yan Li、Xi-Sheng Wang
DOI:10.1016/j.tetlet.2018.07.013
日期:2018.8
A novel palladium-catalyzed C-H formylation of electron-rich N-, O-, and S-containing heteroarenes has been developed. The key to success is that the commercially available BrCHCl2 was used as a stoichiometric carbonyl source. Mechanistic investigations indicated that different from the known Reimer-Tiemann reaction, this net C-H formylation proceeded through an electrophilc radical-type path.
Tandem Olefin Isomerization/Cyclization Catalyzed by Complex Nickel Hydride and Brønsted Acid
作者:Prasad M. Kathe、Alexandru Caciuleanu、Andreas Berkefeld、Ivana Fleischer
DOI:10.1021/acs.joc.0c02033
日期:2020.12.4
We disclose a nickel/Brønsted acid-catalyzed tandem process consisting of double bond isomerization of allyl ethers and amines and subsequent intramolecular reaction with nucleophiles. The process is accomplished by [(Me3P)4NiH]N(SO2CF3)2 in the presence of triflic acid. The methodology provides rapid access to tetrahydropyran-fused indoles and other oxacyclic scaffolds under very low catalyst loadings
Metal-free and regiospecific synthesis of 3-arylindoles
作者:Chuangchuang Xu、Wenlai Xie、Jiaxi Xu
DOI:10.1039/d0ob00317d
日期:——
arylhydrazine hydrochlorides and Fischer indolization. The organic base triethylamine plays a crucial role in the final elimination step in the Fischer indole synthesis, affording 3-arylindoles regiospecifically. The reaction features advantages of microwave acceleration, non-metal participation, short reaction time, organic acid-base co-catalysis, and broad substrate scope.
A novel electron‐donor–acceptor (EDA) complex‐mediated direct CH trifluoromethylation of arenes with Umemoto’s reagent has been developed. This transformation has been enabled by an unprecedented EDA complex formed by Umemoto’s reagent and an amine, which was supported by experiments and theoretical calculations. The radical‐based methodology presented here allows to access highly‐functionalized trifluoromethyl