19350-70-0Relevant academic research and scientific papers
Potassium tert -Butoxide Promoted Synthesis of 4,5-Diaryl-2 H -1,2,3-triazoles from Tosylhydrazones and Nitriles
Qiu, Shanguang,Chen, Yuxue,Song, Xinming,Liu, Li,Liu, Xi,Wu, Luyong
, p. 86 - 90 (2021)
Intermolecular cycloaddition of tosylhydrazones with nitriles was investigated. t -BuOK was shown to be an excellent base for increasing the effectiveness of the reaction in this protocol, and homocoupling of the tosylhydrazones was significantly inhibited by using xylene as a solvent. Through this transformation, a variety of 4,5-diaryl-2 H -1,2,3-triazoles were prepared in good to excellent yields and with high purities. The process is azide-free and transition-metal-free.
Pd-Catalyzed Cascade Metallo-Ene Cyclization/Metallo-Carbene Coupling of Allenamides
Cao, Chengqiang,Yang, Yi,Li, Xin,Liu, Yunxia,Liu, Hui,Zhao, Zengdian,Chen, Lei
supporting information, p. 1538 - 1542 (2021/03/01)
A highly efficient palladium-catalyzed cascade metallo-ene/metallo-carbene coupling reaction was developed to produce 2,3-dihydropyrrole derivatives in high yields. In this transformation, two new Csp3?Csp2 and Csp2?Cspsu
Mn(III)-mediated phosphinoylation of aldehyde hydrazones: Direct “one-pot” synthesis of α-iminophosphine oxides from aldehydes
Bian, Xue-Wei,Zhang, Ling,Shoberu, Adedamola,Zou, Jian-Ping
supporting information, (2021/04/02)
A “one-pot” strategy for the straightforward Mn(III)-mediated phosphinoylation of aldehyde hydrazones with diphenylphosphine oxide to furnish α-iminophosphine oxides is described. This mild and practical method allows the direct use of aldehydes as substrates in one pot to generate the hydrazones, which are then engaged “in situ” by the phosphorus reagent in the presence of Mn(OAc)3 oxidant. Thus, the requisite isolation of the hydrazones is not needed in this operation. Conducted mechanistic experiments implicate a pathway involving phosphorus-centered radicals.
Umpolung Difunctionalization of Carbonyls via Visible-Light Photoredox Catalytic Radical-Carbanion Relay
Wang, Shun,Cheng, Bei-Yi,Sr?en, Matea,K?nig, Burkhard
supporting information, p. 7524 - 7531 (2020/08/05)
The combination of photoredox catalysis with the Wolff-Kishner (WK) reaction allows the difunctionalization of carbonyl groups by a radical-carbanion relay sequence (photo-Wolff-Kishner reaction). Photoredox initiated radical addition to N-sulfonylhydrazones yields α-functionalized carbanions following the WK-type mechanism. With sulfur-centered radicals, the carbanions are further functionalized by reaction with electrophiles including CO2 and aldehydes, whereas CF3 radical addition furnishes a wide range of gem-difluoroalkenes through β-fluoride elimination of the generated α-CF3 carbanions. More than 80 substrate examples demonstrate the broad applicability of this reaction sequence. A series of investigations including radical inhibition, deuterium labeling, fluorescence quenching, cyclic voltammetry, and control experiments support the proposed radical-carbanion relay mechanism.
Copper-catalyzed cross-coupling and sequential allene-mediated cyclization for the synthesis of 1,2,3-triazolo[1,5-a]quinolines
Jiang, Yubo,Ren, Yongsheng,Xiao, Tiebo,Xiong, Shaoqi,Yang, Jianhua
supporting information, p. 7174 - 7182 (2020/10/02)
In this paper, a tandem reaction involving copper-catalyzed cross-coupling and allene-mediated cyclization of 1-(2-ethynylaryl)-1,4-disubstituted-1,2,3-triazole withN-tosylhydrazone has been developed. This method features operational simplicity, excellen
Asymmetric radical cyclopropanation of alkenes with in situ-generated donor-substituted diazo reagents via Co(II)-based metalloradical catalysis
Wang, Yong,Wen, Xin,Cui, Xin,Wojtas, Lukasz,Zhang, X. Peter
supporting information, p. 1049 - 1052 (2017/05/15)
Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradical catalysis (MRC). The cobalt(II) complex of D2-symmetric chiral porphyrin [Co(3,5-DuBu-Xu(2'-Naph)Phyrin)] is an efficient metalloradical catalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical cyclopropanation of a broad range of alkenes, affording the corresponding cyclopropanes in high yields with effective control of both diastereo- and enantioselectivity. This Co(II)-based metalloradical system represents the first catalytic protocol that can effectively utilize donor-type diazo reagents for asymmetric olefin cyclopropanation.
Metal-Free Ring-Expansion Reaction of Six-membered Sulfonylimines with Diazomethanes: An Approach toward Seven-Membered Enesulfonamides
Xia, An-Jie,Kang, Tai-Ran,He, Long,Chen, Lian-Mei,Li, Wen-Ting,Yang, Jin-Liang,Liu, Quan-Zhong
supporting information, p. 1441 - 1444 (2016/02/12)
A new metal-free, ring-expansion reaction of six-membered N-sulfonylimines with unstable diazomethanes, generated in situ from the N-tosylhydrazones, has been developed. This reaction delivers valuable seven-membered enesulfonamides by a Tiffeneau-Demjanov rearrangement and intramolecular proton transfer tautomerization process. Moreover, this ring-expansion reaction can be carried out in a one-pot fashion and scaled up to the gram scale by using aryl aldehydes, without the need to isolate the N-tosylhydrazone. A diazo thing: The title reaction between cyclic N-sulfonylimines and diazo compounds generated in situ from the N-tosylhydrazones is simple and functional-group tolerant. It thus delivers valuable seven-membered sulfonamides in up to 95 % yield. Moreover, this reaction can be carried out in one-pot starting from the aryl aldehydes, without the need to isolate the N-tosylhydrazone (right).
Iron(III) phthalocyanine-chloride-catalyzed synthesis of sulfones from sulfonylhydrazones
Zhao, Jun-Long,Guo, Shi-Huan,Qiu, Jun,Gou, Xiao-Feng,Hua, Cheng-Wen,Chen, Bang
supporting information, p. 2375 - 2378 (2016/05/19)
In this study, sulfones are synthesized from sulfonylhydrazones catalyzed by iron(III) phthalocyanine chloride. This reaction offers broad substrate scope, occurs under mild conditions, utilized readily available reactants, and forms products in good-to-h
Synthesis of terminal allenes through copper-mediated cross-coupling of ethyne with N-tosylhydrazones or α-diazoesters
Ye, Fei,Wang, Chengpeng,Ma, Xiaoshen,Hossain, Mohammad Lokman,Xia, Ying,Zhang, Yan,Wang, Jianbo
, p. 647 - 652 (2016/09/12)
Ethyne is employed as coupling partner in coppermediated cross-coupling reactions with N-tosylhydrazones and α-diazoacetate, leading to the development of a new synthetic method for terminal allenes. With this novel coupling method, the terminal allenes w
Facile one-pot synthesis of N-alkylated benzimidazole and benzotriazole from carbonyl compounds
Meng, Xu,Li, Xiaolong,Chen, Wenlin,Zhang, Yuanqing,Wang, Wen,Chen, Jinying,Song, Jinli,Feng, Huijie,Chen, Baohua
, p. 349 - 356 (2014/04/17)
An efficient one-pot N-alkylation of benzimidazole and benzotriazole from carbonyl compounds and tosylhydrazide has been accomplished via copper powder-catalyzed N - H bond insertion affording N-alkylated products in good yields. The reaction can tolerate a wide range of carbonyl compounds, such as aryl, alkyl, heterocyclic and α,β-unsaturated ketones, and aldehydes.
