3609-45-8Relevant academic research and scientific papers
Visible-light-promoted radical alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester: Synthesis of oxazolines
Ding, Hao,Huang, Panyi,Jin, Can,Su, Weike,Sun, Bin,Yan, Zhiyang,Zhao, Haiyun
supporting information, (2021/10/29)
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.
Cationic nickel(II)-catalyzed hydrosilylation of alkenes: Role of p, n?type ligand scaffold on selectivity and reactivity
Hossain, Istiak,Schmidt, Joseph A.R.
supporting information, p. 3441 - 3451 (2020/10/09)
Seven structurally similar cationic nickel(II)?alkyl complexes were synthesized by using a series of P, N ligands, and their reactivity was explored in the hydrosilylation of alkenes. More electron-rich phosphines enhanced the overall reactivity of the transformation; in contrast, groups on the imine donor had little impact. Overall, these catalysts displayed reactivity and selectivity that was previously unknown or very rare in nickel-catalyzed hydrosilylation. In reactions with Ph2SiH2, 1,2-disubstituted vinylarenes showed complete benzylic selectivity for silane addition, whereas terminal selectivity was observed for 1,1-disubstituted alkenes. The related PhSiH3 led to exclusively Markovnikov selectivity for monosubstituted vinylarenes with no competing double addition observed. Mechanistic investigations supported the hypothesis that a Ni?H functions as the active species in this catalytic hydrosilylation, which in turn also showed catalytic competence for the silane redistribution reaction, especially with sterically unhindered silanes.
Stereoselective Synthesis of Vinylcyclopropa[ b]indolines via a Rh-Migration Strategy
Guo, Pan,Sun, Wangbin,Liu, Yu,Li, Yong-Xin,Loh, Teck-Peng,Jiang, Yaojia
supporting information, p. 5978 - 5983 (2020/08/05)
A mild rhodium catalytic system has been developed to synthesize vinylcyclopropa[b]indolines through cyclopropanation of indoles with vinyl carbenoids generated from ring opening of cyclopropenes in situ. By employing a Rh-migration strategy, the products can be obtained with good to excellent E:Z ratios (≤99:1) and complete diastereoselectivity (≤99:1). This method is easy, has a low catalyst loading, and works for a broad range of functionalities.
Palladium-Catalyzed Methylation of Aryl, Heteroaryl, and Vinyl Boronate Esters
Haydl, Alexander M.,Hartwig, John F.
supporting information, p. 1337 - 1341 (2019/02/26)
A method for the direct methylation of aryl, heteroaryl, and vinyl boronate esters is reported, involving the reaction of iodomethane with aryl-, heteroaryl-, and vinylboronate esters catalyzed by palladium and PtBu2Me. This transformation occurs with a remarkably broad scope and is suitable for late-stage derivatization of biologically active compounds via the boronate esters. The unique capabilities of this method are demonstrated by combining carbon-boron bond-forming reactions with palladium-catalyzed methylation in a tandem transformation.
Synthesis of N-Alkylpyridin-4-ones and Thiazolo[3,2- a]pyridin-5-ones through Pummerer-Type Reactions
Huang, Jingjia,Hu, Gang,An, Shaoyu,Chen, Dongding,Li, Minglei,Li, Pingfan
, p. 9758 - 9769 (2019/08/08)
N-Alkylated 4-pyridones were obtained through a one-pot procedure involving either normal or interrupted Pummerer reactions between triflic anhydride-activated sulfoxides and 4-fluoropyridine derivatives, followed by hydrolysis. On the other hand, triflic anhydride-activated benzyl 6-fluoro-2-pyridyl sulfoxide could react with alkenes or alkynes to afford thiazolo[3,2-a]pyridin-5-ones, via the pyridinium salt intermediates.
Regioselective Diboron-Mediated Semireduction of Terminal Allenes
Gates, Ashley M.,Santos, Webster L.
supporting information, p. 4619 - 4624 (2019/12/11)
A method for the regioselective reduction of the terminal double bond of 1,1-disubstituted allenes has been developed. In the presence of a palladium catalyst, tetrahydroxydiboron and stoichiometric water, allene semireduction proceeds in high yield to afford Z-alkenes selectively.
Iridium-Catalyzed Isomerization of N-Sulfonyl Aziridines to Allyl Amines
Cabré, Albert,Sciortino, Giuseppe,Ujaque, Gregori,Verdaguer, Xavier,Lledós, Agustí,Riera, Antoni
supporting information, 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.
Electrochemical oxidative radical oxysulfuration of styrene derivatives with thiols and nucleophilic oxygen sources
Wang, Yang,Deng, Lingling,Mei, Haibo,Du, Bingnan,Han, Jianlin,Pan, Yi
supporting information, p. 3444 - 3449 (2018/08/06)
Oxydifunctionalization of olefins represents a powerful tool and yet poses a challenging task. Previous methods have usually required a stoichiometric amount of a strong oxidant and an expensive transition-metal catalyst. This work describes the first example of the electrochemical oxysulfuration reaction of olefins with thiols and nucleophilic oxygen sources. This electrochemical difunctionalization reaction is conducted under catalyst- and oxidant-free conditions, and shows good substrate generality, affording thio-substituted alcohols, ethers and γ-lactones in good chemical yields and with excellent regioselectivities. This work represents a new and green strategy for the difunctionalization of olefins, and also provides a complementary and highly valuable prospect for current methodologies for the synthesis of thio-substituted compounds.
Rapid access to cyclopentadiene derivatives through gold-catalyzed cycloisomerization of ynamides with cyclopropenes by preferential activation of alkenes over alkynes
Cheng, Xing,Zhu, Lei,Lin, Meijun,Chen, Jianxin,Huang, Xueliang
supporting information, p. 3745 - 3748 (2017/04/03)
In this communication, gold-catalyzed intermolecular cycloisomerization of cyclopropenes and ynamides is investigated. The current transformation displayed an activation priority of double bonds over triple bonds by the cationic gold catalyst, giving the corresponding cyclopentadienes in good to excellent yields. Additionally, this protocol can be expanded to a one-pot two-step procedure for the synthesis of substituted cyclopentanones.
Asymmetric carbonyl-ene reaction of trifluoropyruvate catalyzed by Pd(II)-SunPhos complex
Jiang, Lili,Hu, Bei,Xie, Xiaomin,Zhang, Zhaoguo
supporting information, p. 6901 - 6905 (2017/10/31)
An efficient asymmetric carbonyl-ene reaction of trifluoropyruvate catalyzed by chiral Pd(II)/(S)-SunPhos complex was developed. A series of optically active homoallylic alcohols containing a CF3 group were obtained with high yields and excellent ee under mild conditions. Particularly, the reaction of isobutylene and trifluoropyruvate gave the desired product (90% yield, 98% ee) with catalyst loading as low as 0.01 mol% in dichloroethane/toluene.
