- Scandium(III) Triflate Catalyzed Direct Synthesis of N-Unprotected Ketimines
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N-Unprotected ketimines are useful substrates and intermediates for synthesizing valuable nitrogen-containing compounds, but their potential applicability is limited by the available synthetic methods. To address this issue, we report a scandium(III) triflate catalyzed direct synthesis of N-unprotected ketimines. Using commercially available reagents and Lewis acid catalysts, ketones were directly transformed into the corresponding N-unprotected ketimines in high yields with broad functional group tolerance, even in multigram scales. The reactions were readily applicable for one-pot synthesis of important compounds such as a glycine Schiff base without isolation of N-unprotected ketimine intermediates. Preliminary mechanistic studies to clarify the reaction mechanism are also described.
- Hirazawa, Yoshinobu,Kadota, Tetsuya,Kondo, Yuta,Morimoto, Hiroyuki,Morisaki, Kazuhiro,Ohshima, Takashi
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supporting information
p. 120 - 125
(2020/02/20)
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- Copper-catalyzed [2+3]-annulation of N-H imines with vinyl azides: Access to polyaryl 2: H -imidazoles
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A practical method for the synthesis of 2H-imidazoles via a [2+3] annulation of N-H imines with vinyl azides using a copper catalyst is developed. In this conversion, environmentally friendly oxygen is used as the sole oxidant and N2 and H2O are the only by-products. The catalytic transformation, operating under mild conditions, is operationally simple and is considered as a readily available catalytic system having good substrate and functional compatibility with high atom-efficiency without the need for additional ligands or additives.
- Zhu, Zhongzhi,Lin, Hanze,Liang, Baihui,Huang, Junjie,Liang, Wanyi,Chen, Lu,Huang, Yubing,Chen, Xiuwen,Li, Yibiao
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supporting information
p. 5621 - 5624
(2020/06/19)
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- Cross-Coupling of Alkyl Redox-Active Esters with Benzophenone Imines: Tandem Photoredox and Copper Catalysis
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Alkyl amines are an important class of organic compounds in medicinal and materials chemistry. Until now very have been very few methods for the synthesis of alkyl amines by metal-catalyzed cross-coupling of alkyl electrophiles with nitrogen nucleophiles. Described here is an approach to employ tandem photoredox and copper catalysis to enable the cross-coupling of alkyl N-hydroxyphthalimide esters, readily derived from alkyl carboxylic acids, with benzophenone-derived imines. Hydrolysis of the coupling products furnish alkylated primary amines. Primary, secondary, and tertiary alkyl groups can be transferred, and the coupling tolerates a diverse set of functional groups. The method allows rapid functionalization of natural products and drugs, and can be used to expedite syntheses of pharmaceuticals from readily available chemical feedstocks.
- Mao, Runze,Balon, Jonathan,Hu, Xile
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supporting information
p. 9501 - 9504
(2018/07/29)
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- Selective Oxidative [4+2] Imine/Alkene Annulation with H2 Liberation Induced by Photo-Oxidation
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The oxidative [4+2] annulation reaction represents an elegant and versatile synthetic protocol for the construction of six-membered heterocyclic compounds. Herein, a photoinduced oxidative [4+2] annulation of NH imines and alkenes was developed by utilizing a dual photoredox/cobaloxime catalytic system. Various multisubstituted 3,4-dihydroisoquinolines can be obtained in good yields. This method is not only obviated the need of stiochiometric amounts of oxidants but also exhibited excellent atom economy by generating H2 as the only byproduct. Remarkably, high regioselectivity and trans diastereoselectivity can be achieved in this transformation even if the Z/E mixture of alkenes were employed.
- Hu, Xia,Zhang, Guoting,Bu, Faxiang,Lei, Aiwen
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supporting information
p. 1286 - 1290
(2018/01/10)
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- Pd-catalyzed enantioselective C-H iodination: Asymmetric synthesis of chiral diarylmethylamines
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An enantioselective C-H iodination reaction using a mono-N-benzoyl- protected amino acid has been developed for the synthesis of chiral diarylmethylamines. The reaction uses iodine as the sole oxidant and proceeds at ambient temperature and under air.
- Chu, Ling,Wang, Xiao-Chen,Moore, Curtis E.,Rheingold, Arnold L.,Yu, Jin-Quan
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supporting information
p. 16344 - 16347
(2013/12/04)
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- Synthesis of substituted benzhydrylamines
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The synthesis of para di- and monosubstituted benzhydrylamines by addition of Grignard reagents to benzonitriles and subsequent reduction, is evaluated and discussed. The reduction step with sodium borohydride allows simple handling and mild conditions. An optimized synthesis of 4,4'-dimethoxybenzhydrylamine by this method is disclosed.
- Dejaegher,Mangelinckx,De Kimpe
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p. 113 - 115
(2007/10/03)
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