213272-97-0Relevant articles and documents
Asymmetric Full Saturation of Vinylarenes with Cooperative Homogeneous and Heterogeneous Rhodium Catalysis
Andersson, Pher G.,Massaro, Luca,Peters, Bram B. C.,Wu, Haibo,Yang, Jianping,Zheng, Jia
supporting information, p. 20377 - 20383 (2021/12/03)
Homogeneous and heterogeneous catalyzed reactions can seldom operate synergistically under the same conditions. Here we communicate the use of a single rhodium precursor that acts in both the homogeneous and heterogeneous phases for the asymmetric full saturation of vinylarenes that, to date, constitute an unmet bottleneck in the field. A simple asymmetric hydrogenation of a styrenic olefin, enabled by a ligand accelerated effect, accounted for the facial selectivity in the consecutive arene hydrogenation. Tuning the ratio between the phosphine ligand and the rhodium precursor controlled the formation of homogeneous and heterogeneous catalytic species that operate without interference from each other. The system is flexible in terms of both the chiral ligand and the nature of the external olefin. We anticipate that our findings will promote the development of asymmetric arene hydrogenations.
Cobaloxime Catalysis for Enamine Phosphorylation with Hydrogen Evolution
Lei, Tao,Liang, Ge,Cheng, Yuan-Yuan,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
supporting information, p. 5385 - 5389 (2020/07/08)
Direct phosphorylation of enamine and enamide with hydrogen evolution was realized via cobaloxime catalysis under visible-light irradiation. Control experiments and spectroscopic studies demonstrated a reductive quenching pathway of cobaloxime catalyst to produce phosphinoyl radical, which underwent cross-coupling with various enamines (and enamides) to give diverse β-phosphinoyl products in good to excellent yields. More interestingly, Z/E mixture of acyclic enamines could convert into single Z-products with good reactivity.
Efficient and practical synthesis of N-acetyl enamides from ketoximes by unique iron catalytic system
Kunishige, Takahiro,Sawada, Daisuke
, p. 1562 - 1565 (2019/05/24)
A new procedure for the iron-catalyzed synthesis of enamides from ketoximes was developed, and its mechanism was proposed. A unique reduction system, with the concerted use of KI and Na2S2O4, was involved. The reaction exhibited a wide substrate scope and gave good yields in a short reaction time. The procedure is operationally simple and also applicable for the large-scale synthesis.
Diphenyliodonium Ion/Et3N Promoted Csp2-H Radical Phosphorylation of Enamides
Pal, Suman,Gaumont, Annie-Claude,Lakhdar, Sami,Gillaizeau, Isabelle
, p. 5621 - 5625 (2019/08/01)
This work reports a simple and efficient method for the direct phosphorylation of enamide under metal-free conditions. The P-centered radicals, derived from secondary phosphine oxides, are generated under mild reaction conditions in the presence of diphenyliodonium salt and Et3N and are introduced onto a range of enamides in good isolated yields. The method features broad substrate scope, good functional group tolerance, and efficient scale-up.
The ruthenium-catalyzed C-H functionalization of enamides with isocyanates: Easy entry to pyrimidin-4-ones
Shi, Pengfei,Li, Song,Hu, Lu-Min,Wang, Cong,Loh, Teck-Peng,Hu, Xu-Hong
, p. 11115 - 11118 (2019/09/20)
Ruthenium-catalyzed heteroannulation between enamides and isocyanates has been realized as a complementary approach to conventional strategies for the synthesis of pyrimidin-4-ones. High step-A nd atom-economy was achieved for the rapid construction of such privileged scaffolds, which are found in a multitude of pharmaceutical compounds. The generality and practicability of this transformation were reflected by the broad scope of substrates with diverse functional groups, large-scale synthesis, and late-stage diversification.
Hypervalent iodane mediated reactions of: N -acetyl enamines for the synthesis of oxazoles and imidazoles
Xu, Kang,Yang, Ruiqi,Yang, Shuang,Jiang, Cheng,Ding, Zhenhua
supporting information, p. 8977 - 8981 (2019/10/28)
A hypervalent iodane reagent used for the intramolecular cyclization of N-acetyl enamines and intermolecular cyclocondensation of enamines and nitriles was investigated. The reaction was performed under mild conditions and gave oxazoles and imidazoles, respectively, in moderate to excellent yields. This transformation exhibits good reactivity, selectivity and functional group tolerance. The selectivity of the intra- or intermolecular reaction is dependent on the structure of N-acetyl enamines.
C(sp2)-H Trifluoromethylation of enamides using TMSCF3: Access to trifluoromethylated isoindolinones, isoquinolinones, 2-pyridinones and other heterocycles
Krishnamurti, Vinayak,Munoz, Socrates B.,Ispizua-Rodriguez, Xanath,Vickerman, Jeffrey,Mathew, Thomas,Surya Prakash
, p. 10574 - 10577 (2018/09/27)
A method for the direct C(sp2)-H trifluoromethylation of enamides, including biologically relevant isoindolinones, isoquinolinones and 2-pyridinones using TMSCF3 under oxidative conditions is presented. The protocol is convenient, operationally simple and exhibits high tolerance across a multitude of relevant handles and functional groups.
METHOD FOR PREPARING ENAMIDE COMPOUND AND RUTHENIUM COMPLEX CATALYST USED THEREIN
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Paragraph 0143, (2017/10/27)
Provided is a method for preparing an enamide compound, which includes reacting an organic azide compound having α-hydrogen and an anhydride by addition of a ruthenium complex catalyst in the presence of an ionic liquid, and a ruthenium complex catalyst u
Highly enantioselective [3+2] coupling of cyclic enamides with quinone monoimines promoted by a chiral phosphoric acid
Zhang, Minmin,Yu, Shuowen,Hu, Fangzhi,Liao, Yijun,Liao, Lihua,Xu, Xiaoying,Yuan, Weicheng,Zhang, Xiaomei
, p. 8757 - 8760 (2016/07/15)
Enantioselective [3+2] coupling of cyclic enamides with quinone monoimines was realised using a chiral phosphoric acid as a catalyst. This transformation allowed for the synthesis of highly enantioenriched polycyclic 2,3-dihydrobenzofurans (up to 99.9% ee). The absolute configuration of one product was determined by an X-ray crystal structural analysis. We also found a possible mechanism for this reaction.
Highly Enantioselective Iridium-Catalyzed Hydrogenation of Cyclic Enamides
Salomó, Ernest,Orgué, Sílvia,Riera, Antoni,Verdaguer, Xavier
, p. 7988 - 7992 (2016/09/13)
The MaxPHOX–Ir catalyst system provided the highest selectivity ever reported for the reduction of cyclic enamides derived from α- and β-tetralones. This result indicates that iridium catalysts are also proficient in reducing alkenes bearing metal-coordinating groups. In the present system, selectivity was pressure-dependent: In most cases, a decrease in the H2pressure to 3 bar resulted in an increase in enantioselectivity. Moreover, the process can be carried out in environmentally friendly solvents, such as methanol and ethyl acetate, with no loss of selectivity.
