723287-08-9Relevant academic research and scientific papers
Iron-Catalyzed Intramolecular Amination of Aliphatic C-H Bonds of Sulfamate Esters with High Reactivity and Chemoselectivity
Liu, Wei,Zhong, Dayou,Yu, Cheng-Long,Zhang, Yan,Wu, Di,Feng, Ya-Lan,Cong, Hengjiang,Lu, Xiuqiang,Liu, Wen-Bo
supporting information, p. 2673 - 2678 (2019/04/30)
It is challenging to develop simple and low cost catalytic systems while maintaining high reactivity and selectivity. An iron-catalyzed intramolecular C-H amination of sulfamate esters using simple and cheap ligands is reported with general substrate scope (31 examples, up to 95% yield). The addition of second ligand, bipyridine, is able to accelerate the reaction and increase the yield. The ready availability of these iron catalysts provides a promising approach to selective introduction of nitrogen into hydrocarbon feedstock.
Heterocyclization involving benzylic C(sp3)-H functionalization enabled by visible light photoredox catalysis
Pandey, Ganesh,Laha, Ramkrishna,Mondal, Pradip Kumar
supporting information, p. 9689 - 9692 (2019/08/15)
A general and efficient method for heterocyclization involving benzylic C(sp3)-H functionalization enabled by visible light photoredox catalysis to access a wide range of structurally diverse oxygen as well as nitrogen heterocycles up to a gram scale is reported. The potential application of this new methodology is demonstrated by the total synthesis of (-)-codonopsinine and (+)-centrolobine. Herein it is proposed that selectfluor, unlike a fluorinating reagent, acts as an oxidative quencher and a hydrogen radical acceptor.
Nonheme iron-mediated amination of C(sp3)-H bonds. Quinquepyridine-supported iron-imide/nitrene intermediates by experimental studies and DFT calculations
Liu, Yungen,Guan, Xiangguo,Wong, Ella Lai-Ming,Liu, Peng,Huang, Jie-Sheng,Che, Chi-Ming
supporting information, p. 7194 - 7204 (2013/06/27)
The 7-coordinate complex [Fe(qpy)(MeCN)2](ClO4) 2 (1, qpy = 2,2′:6′,2″:6″, 2′′′:6′′′,2′′′′- quinquepyridine) is a highly active nonheme iron catalyst for intra- and intermolecular amination of C(sp3)-H bonds. This complex effectively catalyzes the amination of limiting amounts of not only benzylic and allylic C(sp3)-H bonds of hydrocarbons but also the C(sp3)-H bonds of cyclic alkanes and cycloalkane/linear alkane moieties in sulfamate esters, such as those derived from menthane and steroids cholane and androstane, using PhI=NR or "PhI(OAc)2 + H2NR" [R = Ts (p-toluenesulfonyl), Ns (p-nitrobenzenesulfonyl)] as nitrogen source, with the amination products isolated in up to 93% yield. Iron imide/nitrene intermediates [Fe(qpy)(NR)(X)]n+ (CX, X = NR, solvent, or anion) are proposed in these amination reactions on the basis of experimental studies including ESI-MS analysis, crossover experiments, Hammett plots, and correlation with C-H bond dissociation energies and with support by DFT calculations. Species consistent with the formulations of [Fe(qpy)(NTs)2] 2+ (CNTs) and [Fe(qpy)(NTs)]2+ (C) were detected by high-resolution ESI-MS analysis of the reaction mixture of 1 with PhI=NTs (4 equiv). DFT calculations revealed that the reaction barriers for H-atom abstraction of cyclohexane by the ground state of 7-coordinate C NTs and ground state of C are 15.3 and 14.2 kcal/mol, respectively, in line with the observed high activity of 1 in catalyzing the C-H amination of alkanes under mild conditions.
Intramolecular C-N bond formation reactions catalyzed by ruthenium porphyrins: Amidation of sulfamate esters and aziridination of unsaturated sulfonamides
Liang, Jiang-Lin,Yuan, Shi-Xue,Huang, Jie-Sheng,Che, Chi-Ming
, p. 3610 - 3619 (2007/10/03)
Ruthenium porphyrins [Ru(F20-TPP)(CO)] (F20-TPP = 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato dianion) and [Ru(Por*)(CO)] (Por* = 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5, 8-dimethanoanthracen-9-yl]porphyrinato dianion) catalyzed intramolecular amidation of sulfamate esters p-X-C6H4(CH 2)2OSO2NH2 (X = Cl, Me, MeO), XC6H4(CH2)3OSO2NH 2 (X = p-F, p-MeO, m-MeO), and Ar(CH2)2OSO 2NH2 (Ar = naphthalen-1-yl, naphthalen-2-yl) with PhI(OAc)2 to afford the corresponding cyclic sulfamidates in up to 89% yield with up to 100% substrate conversion; up to 88% ee was attained in the asymmetric intramolecular amidation catalyzed by [Ru(Por*)(CO)]. Reaction of [Ru(F20-TPP)(CO)] with PhI=NSO2OCH 2CCl3 (prepared by treating the sulfamate ester Cl 3CCH2OSO2NH2 with PhI(OAc) 2) afforded a bis(imido)ruthenium(VI) porphyrin, [Ru VI(F20-TPP)(NSO2OCH2CCl 3)2], in 60% yield. A mechanism involving reactive imido ruthenium porphyrin intermediate was proposed for the ruthenium porphyrin-catalyzed intramolecular amidation of sulfamate esters. Complex [Ru(F20-TPP)(CO)] is an active catalyst for intramolecular aziridination of unsaturated sulfonamides with PhI(OAc)2, producing corresponding bicyclic aziridines in up to 87% yield with up to 100% substrate conversion and high turnover (up to 2014).
