34535-98-3Relevant articles and documents
Detection of Fleeting Amine Radical Cations and Elucidation of Chain Processes in Visible-Light-Mediated [3 + 2] Annulation by Online Mass Spectrometric Techniques
Cai, Yi,Wang, Jiang,Zhang, Yuexiang,Li, Zhi,Hu, David,Zheng, Nan,Chen, Hao
, p. 12259 - 12266 (2017)
Visible-light-mediated photoredox reactions have recently emerged as a powerful means for organic synthesis and thus have generated significant interest from the organic chemistry community. Although the mechanisms of these reactions have been probed by a number of techniques such as NMR, fluorescence quenching, and laser flash photolysis and various degrees of success has been achieved, mechanistic ambiguity still exists (for instance, the involvement of the chain mechanism is still under debate) because of the lack of structural information about the proposed and short-lived intermediates. Herein, we present the detection of transient amine radical cations involved in the intermolecular [3 + 2] annulation reaction of N-cyclopropylaniline (CPA, 1) and styrene 2 by electrospray ionization mass spectrometry (ESI-MS) in combination with online laser irradiation of the reaction mixture. In particular, the reactive CPA radical cation 1+?, the reduced photocatalyst Ru(I)(bpz)3+, and the [3 + 2] annulation product radical cation 3+? are all successfully detected and confirmed by high-resolution MS. More importantly, the post-irradiation reaction with an additional substrate, isotope-labeled CPA, following photolysis of 1, 2, and Ru catalyst provides strong evidence to support the chain mechanism in the [3 + 2] annulation reaction. Furthermore, the key step of the proposed chain reaction, the oxidation of CPA 1 to amine radical cation 1+? by product radical cation 3+? (generated using online electrochemical oxidation of 3), is successfully established. Additionally, the coupling of ESI-MS with online laser irradiation has been successfully applied to probe the photostability of photocatalysts.
Red-Light-Induced N, N'-Dipropyl-1,13-dimethoxyquinacridinium-Catalyzed [3+2] Cycloaddition of Cyclopropylamines with Alkenes or Alkynes
Gianetti, Thomas L.,Mei, Liangyong,Stull, Savannah M.
supporting information, (2021/11/30)
A red-light-mediated [3+2] annulation of cyclopropylamines with akenes or alkynes in the presence of N,N'-dipropyl-1,13-dimethoxyquinacridinium is reported. An array of cyclopentane or cyclopentene derivatives with diverse functional groups have been obta
PEt3-mediated deoxygenative C–N coupling of nitroarenes and boronic acids
Nykaza, Trevor V.,Yang, Junyu,Radosevich, Alexander T.
supporting information, p. 3248 - 3252 (2019/04/25)
A method for the preparation of aryl- and heteroarylamine products by triethylphosphine-mediated deoxygenative coupling of nitroarenes and boronic acids is reported. This method provides access to an array of functionalized (hetero)arylamine products from readily available starting materials under the action of an inexpensive commercial reagent. The developed triethylphosphine-mediated transformation highlights the capability of organophosphorus compounds to carry out this useful deoxygenative transformation without the necessity of any transition metal additives.
Dirhodium(II)-catalyzed [3 + 2] cycloaddition of N-arylaminocyclopropane with alkyne derivatives
Liu, Wentong,Kuang, Yi,Wang, Zhifan,Zhu, Jin,Wang, Yuanhua
supporting information, p. 542 - 550 (2019/03/08)
Dirhodium(II) complex-catalyzed [3 + 2] reactions between N-arylaminocyclopropanes and alkyne derivatives are described. The cycloaddition products proved to be versatile synthetic intermediates. trans-Cyclic β-amino acids and derivatives thereof can be c