177750-08-2Relevant academic research and scientific papers
Fe(III)-catalyzed Oxidative Povarov Reaction with Molecular Oxygen Oxidant
Park, Du Yong,Hwang, Joon Young,Kang, Eun Joo
, p. 798 - 801 (2021)
The synthesis of tetrahydroquinoline derivatives from dimethyl anilines and enamides has been developed by Fe(III)-phenanthroline complex under aerobic condition. The oxidation of tertiary anilines involving a single electron transfer of Fe(phen)3(PF6)3 afforded the iminium ion intermediate, which reacted with electron-rich alkenes to build a six-membered N-heterocycles containing quaternary carbon center via the oxidative Povarov reaction process.
Visible-light-promoted olefinic trifluoromethylation of enamides with CF3SO2Na
Chen, Kai,Chen, Yixuan,Guan, Jianping,Tang, Kai,Wang, Zhujun,Xiang, Haoyue,Yang, Hua
supporting information, p. 7475 - 7479 (2021/09/08)
A visible-light-promoted olefinic C-H trifluoromethylation of enamides was developed by employing cheap and stable Langlois’ reagent as the CF3source. A series of β-CF3enamides were obtained in moderate to good yields with highE-isomer selectivity under mild conditions. Preliminary mechanistic studies suggest that molecular oxygen acts as the terminal oxidant for this net oxidative process, and theEisomer selectivity could be well explained by a base-assisted deprotonation of the cation intermediate.
Access to multi-functionalized oxazolines via silver-catalyzed heteroannulation of enamides with sulfoxonium ylides
Liu, Rui-Hua,Shan, Qi-Chao,Gao, Ya,Loh, Teck-Peng,Hu, Xu-Hong
supporting information, p. 1411 - 1414 (2020/10/29)
Disclosed herein is an efficient Ag-catalyzed [4 + 1] heteroannulation reaction of enamides with α-carbonyl sulfoxonium ylides. The diastereoselective transformation provides a practical access to a diverse range of multi-functionalized oxazoline derivatives. The synthetic utility of the resultant tetra-substituted oxazolines is further demonstrated by a series of useful manipulations into valuable building blocks of pharmaceutical relevance.
Rhodium(III)-Catalyzed Direct C-H Arylation of Various Acyclic Enamides with Arylsilanes
Li, Xiaolan,Sun, Kai,Shen, Wenjuan,Zhang, Yong,Lu, Ming-Zhu,Luo, Xuzhong,Luo, Haiqing
supporting information, p. 31 - 36 (2021/01/09)
The stereoselective β-C(sp2)-H arylation of various acyclic enamides with arylsilanes via Rh(III)-catalyzed cross-coupling reaction was illustrated. The methodology was characterized by extraordinary efficacy and stereoselectivity, a wide scope of substrates, good functional group tolerance, and the adoption of environmentally friendly arylsilanes. The utility of this present method was evidenced by the gram-scale synthesis and further elaboration of the product. In addition, Rh(III)-catalyzed C-H activation is considered to be the critical step in the reaction mechanism.
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.
Selective Dehydrogenative Acylation of Enamides with Aldehydes Leading to Valuable β-Ketoenamides
Liu, Rui-Hua,Shen, Zhen-Yao,Wang, Cong,Loh, Teck-Peng,Hu, Xu-Hong
supporting information, p. 944 - 949 (2020/02/15)
We have presented a unique example of dehydrogenative acylation of enamides with aldehydes enabled by an earth-abundant iron catalyst. The protocol provides the straightforward access to valuable β-ketoenamides with ample substrate scope and excellent functional group tolerance. Notably, distinct C-H acylation of enamide rather than at N-H moiety site occurs with absolute Z-selectivity was observed. Late-stage modifications of complex molecules and versatile synthetic utility of β-ketoenamides further highlight the practicability of this transformation.
Direct Enamido C(sp2)?H Diphosphorylation Enabled by a PCET-Triggered Double Radical Relay: Access to gem-Bisphosphonates
Cao, Hao-Qiang,Liu, Hao-Nan,Liu, Zhe-Yuan,Ma, Jun-An,Qiao, Bao-Kun,Zhang, Fa-Guang
supporting information, p. 5515 - 5521 (2020/04/27)
Herein we report a novel and straightforward protocol for the construction of valuable gem-BPs by means of proton-coupled electron-transfer (PCET)-triggered enamido C(sp2)?H diphosphorylation. This reaction represents a rare example of realizing the challenging double C?P bond formation at a single carbon atom, thus providing facile access to a broad variety of structurally diverse bisphosphonates from simple enamides under silver-mediated conditions. Initial mechanistic studies demonstrated that the diphosphorylation involves two rounds of PCET-initiated radical relay process.
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
supporting information, 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.
Nickel-Catalyzed Transformation of Diazoacetates to Alkyl Radicals Using Alcohol as a Hydrogen Source
Zhao, Jingjing,Li, Pan,Xu, Yaohua,Shi, Yixin,Li, Fuwei
supporting information, p. 9386 - 9390 (2019/11/28)
A nickel-catalyzed transformation of diazoacetates to α-carbonyl methylene radicals has been disclosed in the presence of hyperoxide using ethanol as a hydrogen source and solvent. This strategy is successfully applied in the formation of indolin-2-ones or 1,4-dicarbonyl compounds from acrylamides or enamides in moderate to good yields. These reactions undergo radical addition onto C-C double bonds followed by a cyclization/oxidation or an oxidation/hydrolysis process, respectively.
