25797-05-1Relevant academic research and scientific papers
Photoredox Cyanomethylation of Indoles: Catalyst Modification and Mechanism
O'Brien, Connor J.,Droege, Daniel G.,Jiu, Alexander Y.,Gandhi, Shivaani S.,Paras, Nick A.,Olson, Steven H.,Conrad, Jay
, p. 8926 - 8935 (2018/07/05)
The direct cyanomethylation of indoles at the 2- or 3-position was achieved via photoredox catalysis. The versatile nitrile synthon is introduced as a radical generated from bromoacetonitrile, a photocatalyst, and blue LED as a light source. The mechanism of the reaction is explored by determination of the Stern-Volmer quenching constants. By combining photophysical data and mass spectrometry to follow the catalyst decomposition, the catalyst ligands were tuned to enable synthetically useful yields of radical coupling products. A range of indole substrates with alkyl, aryl, halogen, ester, and ether functional groups participate in the reaction, affording products in 16-90% yields. The reaction allows the rapid construction of synthetically useful cyanomethylindoles, products that otherwise require several synthetic steps.
Vinylic MIDA boronates: New building blocks for the synthesis of aza-heterocycles
Llona-Minguez, Sabin,Desroses, Matthieu,Ghassemian, Artin,Jacques, Sylvain A.,Eriksson, Lars,Isacksson, Rebecka,Koolmeister, Tobias,Stenmark, P?l,Scobie, Martin,Helleday, Thomas
, p. 7394 - 7398 (2015/05/13)
Abstract A two-step synthesis of structurally diverse pyrrole-containing bicyclic systems is reported. ortho-Nitro-haloarenes coupled with vinylic N-methyliminodiacetic acid (MIDA) boronates generate ortho-vinyl-nitroarenes, which undergo a "metal-free" nitrene insertion, resulting in a new pyrrole ring. This novel synthetic approach has a wide substrate tolerance and it is applicable in the preparation of more complex "drug-like" molecules. Interestingly, an ortho-nitro-allylarene derivative furnished a cyclic β-aminophosphonate motif. Old dog, new tricks: A two-step synthesis of structurally diverse pyrrole-containing bicyclic systems is reported. ortho-Nitro-haloarenes coupled with vinylic N-methyliminodiacetic acid (MIDA) boronates generate ortho-vinyl-nitroarenes, which undergo a "metal-free" nitrene insertion, resulting in a new pyrrole ring. This approach has a wide substrate tolerance and it is applicable in the preparation of more complex "drug-like" molecules. Interestingly, an ortho-nitro-allylarene derivative furnished a cyclic β-aminophosphonate motif.
Palladium-catalyzed indole and azaindole synthesis by direct annulation of electron-poor o-chloroanilines and o-chloroaminopyridines with aldehydes
Xu, Zhengren,Hu, Weimin,Zhang, Fengying,Li, Qingjiang,Lue, Zhiyao,Zhang, Lihe,Jia, Yanxing
experimental part, p. 3981 - 3987 (2009/05/27)
A practical process for the synthesis of 2-unsubstituted indoles and azaindoles has been developed by the palladium-catalyzed direct annulation of electron-poor o-chloro/bromoanilines and o-chloroaminopyridines with aldehydes. Coupled with the previous results of Jia and Zhu, this allows rapid access to a variety of 2-unsubstituted indoles and azaindoles starting from simple and easily accessible precursors. Georg Thieme Verlag Stuttgart.
