58567-50-3Relevant academic research and scientific papers
Alkene: Versus alkyne reactivity in unactivated 1,6-enynes: Regio-And chemoselective radical cyclization with chalcogens under metal-And oxidant-free conditions
Kudale, Vishal Suresh,Li, Jing,Mutra, Mohana Reddy,Tsai, Wu-Hsun,Wang, Jeh-Jeng
supporting information, p. 2288 - 2300 (2020/04/21)
Herein, we have developed metal and oxidant-free visible light-promoted alkene vs. alkyne regio-And chemoselective radical cascade cyclization of electronically unbiased 1,6-enynes with chalcogens to synthesize substituted pyrrolidines bearing chalcogens. The reaction generated three new bonds, namely, C-SO2, C-C, and C-Se under extremely mild conditions. Furthermore, we achieved regio-And chemoselective mono-addition of aromatic thiophenols with unactivated 1,6-enynes. The key features of this protocol are broad substrate scope, environment-friendly conditions, operational simplicity, atom economy, and amenability to gram-scale synthesis. The mechanistic studies corroborate that the reaction proceeds via a radical pathway.
Copper-Catalyzed 1,2-Methoxy Methoxycarbonylation of Alkenes with Methyl Formate
Budai, Balázs,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
supporting information, p. 10305 - 10309 (2019/06/27)
Reported here is a copper-catalyzed 1,2-methoxy methoxycarbonylation of alkenes by an unprecedented use of methyl formate as a source of both the methoxy and the methoxycarbonyl groups. This reaction transforms styrene and its derivatives into value-added β-methoxy alkanoates and cinnamates, as well as medicinally important five-membered heterocycles, such as functionalized tetrahydrofurans, γ-lactones, and pyrrolidines. A ternary β-diketiminato-CuI-styrene complex, fully characterized by NMR spectroscopy and X-ray crystallographic analysis, is capable of catalyzing the same transformation. These findings suggest that pre-coordination of electron-rich alkenes to copper might play an important role in accelerating the addition of nucleophilic radicals to electron-rich alkenes, and could have general implications in the design of novel radical-based transformations.
Enantioselective Synthesis of β-Methyl Amines via Iridium-Catalyzed Asymmetric Hydrogenation of N-Sulfonyl Allyl Amines
Cabré, Albert,Verdaguer, Xavier,Riera, Antoni
, p. 4196 - 4200 (2019/08/16)
The iridium-catalyzed asymmetric hydrogenation of several N-sulfonyl allyl amines is reported. All substrates can be easily obtained by the Ir-catalyzed isomerization of N-tosylaziridines reported previously. The commercially available threonine-derived phosphinite (UbaPHOX) iridium complex has been found to be the best catalyst for this catalytic application, affording β-methyl amines with good to excellent ee values (up to 94%). The synthetic potential of this novel methodology was demonstrated by the formal synthesis of Lorcaserin and LY-404187. (Figure presented.).
Catalytic Geminal Difluorination of Styrenes for the Construction of Fluorine-rich Bioisosteres
Scheidt, Felix,Neufeld, Jessica,Sch?fer, Michael,Thiehoff, Christian,Gilmour, Ryan
, p. 8073 - 8076 (2019/01/04)
A geminal difluorination of alkenes based on I(I)/I(III) catalysis is disclosed, which is compatible with a range of electronically and substitutionally diverse styrenes (27 examples, up to 89% yield). Employing inexpensive p-TolI as the organocatalyst, turnover is enabled by Selectfluor-mediated oxidation to generate the ArIF2 species in situ. Extension to include α-substituted styrenes bearing fluorine-containing groups is disclosed and provides an expansive platform for the generation of fluorine-rich architectures.
Palladium-catalyzed heck-type cascade cyclization of (Z)-1-iodo-1,6-dienes with N-tosyl hydrazones
Li, Jun,Chi, Xiaochen,Meng, Long,Jiao, Luyang,Shang, Wenhui,Wang, Ping,Zhang, Daopeng,Dong, Yunhui,Liu, Qing,Liu, Hui
supporting information, p. 7356 - 7360 (2018/10/24)
A palladium-catalyzed heck-type cascade cyclization of (Z)-1-iodo-1,6-dienes with N-tosyl hydrazones is reported. The alkylpalladium intermediate coupled with the diazo compound, generating the second alkylpalladium species bearing two β-H, which generate
Iridium-Catalyzed Isomerization of N-Sulfonyl Aziridines to Allyl Amines
Cabré, Albert,Sciortino, Giuseppe,Ujaque, Gregori,Verdaguer, Xavier,Lledós, Agustí,Riera, Antoni
, p. 5747 - 5751 (2018/09/21)
The Crabtree's reagent catalyzes the isomerization of N-sulfonyl 2,2-disubstituted aziridines to allyl amines. The selectivity of allyl amine vs imine is very high (up to 99/1). The unprecedented isomerization takes place in mild conditions without activation of the catalyst by hydrogen. The mechanism has been studied computationally by DFT calculations; instead of the usual hydrogenation of COD, the catalytic species is formed by a loss of the pyridine ligand. Approaching of aziridine to this unsaturated species leads to a carbocation intermediate through a low energy barrier. A metal-mediated tautomerization involving sequentially γ-H elimination and N-H reductive elimination affords selectively the allyl amine. The readiness of the CγH bond to participate in the H elimination step accounts for the selectivity toward the allyl amine product.
Chiral Cu(salen)-Based Metal-Organic Framework for Heterogeneously Catalyzed Aziridination and Amination of Olefins
Liu, Yan,Li, Zijian,Yuan, Guozan,Xia, Qingchun,Yuan, Chen,Cui, Yong
supporting information, p. 12500 - 12503 (2016/12/26)
A homochiral 3D porous metal-organic framework was assembled from a chiral dicarboxylic acid-functionalized Cu(salen)-based catalyst and could serve as an efficient heterogeneous catalyst for aziridination and allylic amination of olefins. Besides easy separation and reuse of the catalyst, the chiral framework confinement could impart substrate size selectivity, enhance catalyst activity, and induce product enantioselectivity.
Iodine-Catalyzed Decarboxylative Amidation of β,γ-Unsaturated Carboxylic Acids with Chloramine Salts Leading to Allylic Amides
Kiyokawa, Kensuke,Kojima, Takumi,Hishikawa, Yusuke,Minakata, Satoshi
supporting information, p. 15548 - 15552 (2015/11/03)
The iodine-catalyzed decarboxylative amidation of β,γ-unsaturated carboxylic acids with chloramine salts is described. This method enables the regioselective synthesis of allylic amides from various types of β,γ-unsaturated carboxylic acids containing sub
Lewis acid mediated intramolecular C-C bond formation of alkyne-epoxide leading to six-membered nitrogen and oxygen heterocycles
Ghosh, Priya,Saha, Pipas,Bondalapati, Somasekhar,Indukuri, Kiran,Saikia, Anil K.
, p. 4119 - 4124 (2014/05/20)
Intramolecular C-C bond formation of oxygen- and nitrogen-tethered alkynes and epoxide mediated by Lewis acid under ambient conditions is described. A simple procedure for the synthesis of 3,6- and 5,6-dihydropyrans and 3,4-dehydropiperidines from acyclic
Diverse reactivity in a rhodium(III)-catalyzed oxidative coupling of N-allyl arenesulfonamides with alkynes
Wang, Dongqi,Wang, Fen,Song, Guoyong,Li, Xingwei
, p. 12348 - 12352 (2013/02/23)
Olefinic CiH activation of N-allyl sulfonamides in the presence of [{RhCpCl2}2] (Cp=Me5C5) enabled their oxidative coupling with alkynes to generate 1,2-dihydropyridines, pyridines, and cyclopentenones (see scheme; Ts=p-toluenesulfonyl). The type of highly substituted product formed was controlled by the substitution of the allyl group and the reaction conditions. Copyright
