17099-22-8Relevant academic research and scientific papers
Metal-free regioselective C-H amination for the synthesis of pyrazole-containing 2H-indazoles
Wang, Kai,Wei, Tingting,Zhang, Yujia,Hou, Jiahao,Bai, Renren,Xie, Yuanyuan
, p. 1787 - 1794 (2021/03/14)
A general and practical regioselective approach for the C-H amination of 2H-indazoles under transition-metal-free conditions was developed. A series of substrates were tested showing eminent functional group tolerance and affording the C-N functionalization products in good to excellent yields. Mechanism studies revealed that a radical process was involved in this transformation.
Tert-Butyl Hydroperoxide-Mediated Oxo-Sulfonylation of 2 H-Indazoles with Sulfinic Acid toward Indazol-3(2 H)-ones
Ghosh, Payel,Mondal, Susmita,Hajra, Alakananda
supporting information, p. 1086 - 1090 (2020/02/04)
A new and efficient oxo-sulfonylation protocol has been established for the synthesis of N-sulfonylated indazolones employing sulfinic acid as a sulfonylating agent using tert-butyl hydroperoxide (TBHP) under ambient air. A series of structurally diverse 1-sulfonylindazol-3(2H)-one derivatives were obtained in good yields. A radical reaction mechanism has been proposed for this transformation.
Dehydrogenation and α-functionalization of secondary amines by visible-light-mediated catalysis
Bujok, Robert,Morawska, Paulina,Pawlowski, Robert,Stanek, Filip,Stodulski, Maciej
, p. 2103 - 2112 (2020/03/27)
A visible-light-mediated process for dehydrogenation of amines has been described. The given protocol showed a broad substrate scope, mild reaction conditions and excellent results without the requirement of tedious purification. This process can be applied in one-pot functionalization of secondary amines with various nucleophiles through the cooperation of visible-light and Lewis acid catalysis, leading to the structurally varied essential components of biologically active molecules. In addition, Stern-Volmer studies and quenching experiments revealed the role of a catalyst and led to the proposed mechanism of this transformation.
Visible-light-induced regioselective cross-dehydrogenative coupling of 2 H-indazoles with ethers
Singsardar, Mukta,Laru, Sudip,Mondal, Susmita,Hajra, Alakananda
, p. 4543 - 4550 (2019/04/30)
A visible-light-promoted regioselective C(sp2)-H/C(sp3)-H cross-dehydrogenative coupling between 2H-indazoles and ethers has been achieved using a catalytic amount of rose bengal as an organophotoredox-catalyst and tert-butyl hydroperoxide (TBHP) as an oxidant at ambient temperature under aerobic conditions. A variety of C-3 oxyalkylated 2H-indazoles have been synthesized in moderate to good yields. Mechanistic studies suggest a radical pathway of the present reaction.
Au/Ag-Mo nano-rods catalyzed reductive coupling of nitrobenzenes and alcohols using glycerol as the hydrogen source
Cui, Xinjiang,Zhang, Chengming,Shi, Feng,Deng, Youquan
supporting information; experimental part, p. 9391 - 9393 (2012/09/21)
A highly efficient Au/Ag-Mo nano-rods catalyst was prepared for the one-pot synthesis of imine and amine using equal molar ratio of nitrobenzene and alcohol as starting materials, and bio-based glycerol as the hydrogen source. The reaction mechanism of the nitrobenzene reduction, amine and aldehyde coupling, and imine reduction was explored.
Oxidative rearrangement of imines to formamides using sodium perborate
Nongkunsarn, Pakawan,Ramsden, Christopher A.
, p. 3805 - 3830 (2007/10/03)
Oxidation of C-aryl or alkyl-N-arylaldimines 6 or 20 by sodium perborate tetrahydrate (SPB) in trifluoroacetic acid solution gives rearranged N,N-disubstituted formamides 9 and 21. Yields are variable and solvent dependant with the best yields (50-60%) being obtained for electronically neutral C-aryl substituents or C-s-alkyl substituents. Product formation is rationalised in terms of an intermediate oxaziridine 5 that rearranges via acid catalysed O-N bond cleavage. An alternative C-O bond cleavage of these intermediates accounts for the formation of aldehydes, which are common by products. Rearrangement appears to be favoured by N-aryl substituents and by C-substituents that do not stabilise a developing positive charge on carbon. Further support for an oxaziridine intermediate 5 is provided by the observation that MCPBA oxidation of benzaldehyde phenylimine gives rearranged N,N-diphenylformamide. Under the conditions of the SPB oxidative rearrangements, oxaziridine formation may well occur by initial formation of trifluoroperacetic acid. Stereochemical aspects of this novel rearrangement of aldimines 1 → 2 have been investigated using trans- and cis-myrtanal 25 and 30. The observed epimerisation using die N-4-tolyl imine of trans-myrtanal 26 is believed to arise from equilibration of the precursor imine 26 with the tautomeric enamine 35b.
