20878-31-3Relevant academic research and scientific papers
Photoinduced [3+2] Annulation of Alkene with o-Iodoanilines: An Expedient Approach to Indolines
Zhao, Xinxin,Guo, Lin,Yang, Chao,Xia, Wujiong
, p. 1341 - 1348 (2020/11/19)
A highly regioselective [3+2] cyclization of alkenes with 2-iodoanilines under the irradiation of UV light is described. This general, metal-free strategy facilitates the direct preparation of 2-mono-/disubstituted indolines as well as spiroindolines through alkene carboamination in one step. Mechanistic studies suggested that the photochemical protocol proceeded via a radical pathway.
Chiral Br?nsted Acid from Chiral Phosphoric Acid Boron Complex and Water: Asymmetric Reduction of Indoles
Yang, Kai,Lou, Yixian,Wang, Chenglan,Qi, Liang-Wen,Fang, Tongchang,Zhang, Feng,Xu, Hetao,Zhou, Lu,Li, Wangyang,Zhang, Guan,Yu, Peiyuan,Song, Qiuling
supporting information, p. 3294 - 3299 (2020/01/21)
A new chiral Br?nsted acid, generated in situ from a chiral phosphoric acid boron (CPAB) complex and water, was successfully applied to asymmetric indole reduction. This “designer acid catalyst”, which is more acidic than TsOH as suggested by DFT calculations, allows the unprecedented direct asymmetric reduction of C2-aryl-substituted N-unprotected indoles and features good to excellent enantioselectivities with broad functional group tolerance. DFT calculations and mechanistic experiments indicates that this reaction undergoes C3-protonation and hydride-transfer processes. Besides, bulky C2-alkyl-substituted N-unprotected indoles are also suitable for this system.
Frustrated Lewis Pair Catalyzed Dehydrogenative Oxidation of Indolines and Other Heterocycles
Maier, Alexander F. G.,Tussing, Sebastian,Schneider, Tobias,Fl?rke, Ulrich,Qu, Zheng -Wang,Grimme, Stefan,Paradies, Jan
supporting information, p. 12219 - 12223 (2016/10/13)
An acceptorless dehydrogenation of heterocycles catalyzed by frustrated Lewis pairs (FLPs) was developed. Oxidation with concomitant liberation of molecular hydrogen proceeded in high to excellent yields for N-protected indolines as well as four other substrate classes. The mechanism of this unprecedented FLP-catalyzed reaction was investigated by mechanistic studies, characterization of reaction intermediates by NMR spectroscopy and X-ray crystal analysis, and by quantum-mechanical calculations. Hydrogen liberation from the ammonium hydridoborate intermediate is the rate-determining step of the oxidation. The addition of a weaker Lewis acid as a hydride shuttle increased the reaction rate by a factor of 2.28 through a second catalytic cycle.
α-Alkylation of tertiary amines by C(sp3)–C(sp3) cross-coupling under redox neutral photocatalysis
Pandey, Ganesh,Tiwari, Sandip Kumar,Singh, Bhawana
supporting information, p. 4480 - 4483 (2016/09/14)
Direct α-alkylation of N-phenyl-tetrahydroisoquinoline with alkyl selenides of desired alkyl chain length and functionality is reported by photoredox catalysis. Construction of hexahydro pyrrolo- and pyrido-isoquinoline scaffolds along with indolines and tetrahydroquinolines is also described by intramolecular C(sp3)–C(sp3) cross-couplings.
Chiral phosphoric acid-catalyzed oxidative kinetic resolution of indolines based on transfer hydrogenation to imines
Saito, Kodai,Shibata, Yukihiro,Yamanaka, Masahiro,Akiyama, Takahiko
, p. 11740 - 11743 (2013/09/02)
The oxidative kinetic resolution of 2-substituted indoline derivatives was achieved by hydrogen transfer to imines by means of a chiral phosphoric acid catalyst. The oxidative kinetic resolution was applicable to racemic alkyl- or aryl-substituted indolines, and the remaining indolines were obtained in good yields with excellent enantioselectivities.
Metal-free catalytic hydrogenation of polar substrates by frustrated Lewis pairs
Stephan, Douglas W.,Greenberg, Sharonna,Graham, Todd W.,Chase, Preston,Hastie, Jeff J.,Geier, Stephen J.,Farrell, Jeffrey M.,Brown, Christopher C.,Heiden, Zachariah M.,Welch, Gregory C.,Ullrich, Matthias
scheme or table, p. 12338 - 12348 (2012/01/31)
In 2006, our group reported the first metal-free systems that reversibly activate hydrogen. This finding was extended to the discovery of "frustrated Lewis pair" (FLP) catalysts for hydrogenation. It is this catalysis that is the focal point of this artic
