Indole Functionalization via Photoredox Gold Catalysis
作者:Sherif J. Kaldas、Alexandre Cannillo、Terry McCallum、Louis Barriault
DOI:10.1021/acs.orglett.5b01260
日期:2015.6.5
photoredox catalyst [Au2(dppm)2]Cl2 to initiate free-radical cyclizations onto indoles is reported. Excitation of the dimeric Au(I) photocatalyst for the reduction of unactivated bromoalkanes and bromoarenes is used for the generation of carbon-centered radicals. Previous to this work, reduction processes leading to indole functionalization utilizing photoredox catalysts were limited to activated benzylic
Radical Cycloaddition by Nickel(II) Complex-Catalyzed Electroreduction. A Method for Preparation of Pyrrolopyridine and Pyrrolopyrrole Derivatives.
作者:Shigeko OZAKI、Shizue MITOH、Hidenobu OHMORI
DOI:10.1248/cpb.44.2020
日期:——
Cycloalkano[α]pyrroles were obtained by reductive radical cycloaddition of 1-(2-iodoethyl)pyrrole and activated olefins or by cyclization of 1-(ω-iodoalkyl)pyrroles, through electroreduction of the iodides using nickel(II) complex as an electron-transfer catalyst.
A new convenient three-step synthesis of the privileged CNS scaffold 1,2,3,4,10,10a-hexahydropyrazino[1,2-a]indoles has been developed. The method makes use of an intramolecular carbene-mediated C-H insertion in phenylpiperazine-derived tosylhydrazones made from 2-fluorobenzaldehydes. Notably, the piperazine can be replaced with other cyclic nitrogen bases and the methodology is successfully extended to pyrrolidine, piperidine, azepane, morpholine, and homopiperazine.
Hydrogenation of compounds containing an indolizine moiety and of 1-benzylisoquinoline over rhenium heptasulfide
作者:R. Alarkon Khorkhe、S. A. Soldatova、A. T. Soldatenkov、M. A. Ryashentseva、N. S. Prostakov
DOI:10.1007/bf00961308
日期:1991.6
It was shown by hydrogenation of 2,8-diphenylindolizine, benzo[2,3]indolizine, dibenzo[2,3;5,6]indolizine, dibenzo[2,3;7,8]indolizine, 1-benzylisoquinoline, and 2,3-dimethyl-6-ethyl-4-(4-nitrophenyl)pyridine over Re2S7 (250-degrees-C, P(H-2) = 140 atm, 4 h) that the pyridine ring in benzoindolizines is hydrolyzed in preference to the pyrrole ring. Phenyl substituents at the indolizine do not prevent its complete reduction while alkyl substituents make reduction difficult. Annelation of the pyrrole and pyridine rings of indolizine lower the degree of its reduction; a nitro group is reduced to an amino group.