177750-24-2Relevant academic research and scientific papers
Visible-light-promoted olefinic trifluoromethylation of enamides with CF3SO2Na
Tang, Kai,Chen, Yixuan,Guan, Jianping,Wang, Zhujun,Chen, Kai,Xiang, Haoyue,Yang, Hua
, 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.
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
, 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.
Synthesis of Functionalized Vinylsilanes via Metal-Free Dehydrogenative Silylation of Enamides
Chang, Xi-Hao,Wang, Zi-Lu,Zhao, Meng,Yang, Chao,Li, Jie-Jun,Ma, Wei-Wei,Xu, Yun-He
, p. 1326 - 1330 (2020/02/13)
A novel method of metal-free dehydrogenative silylation of enamides has been developed. The desired functionalized vinylsilane products were obtained in moderate to good yield and with high stereoselectivities. This protocol displays good tolerance of various functionalities. Furthermore, the high chemoselectivity of this reaction enables us to introduce different unsaturated C-C moieties to the products. The ease of further derivatization of the products to other useful compounds also demonstrates the highly synthetic utility of the current methodology.
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
, 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.
Merging alkenyl C-H activation with the ring-opening of 1,2-oxazetidines: Ruthenium-catalyzed aminomethylation of enamides
Hu, Lu-Min,Hu, Xu-Hong,Li, Song,Ma, Xue-Qing,Shan, Qi-Chao
, p. 7969 - 7972 (2020/09/09)
1,2-Oxazetidines have been utilized as formaldimine precursors for the direct aminomethylation of enamides under a Ru(ii) species. By merging alkenyl C-H activation with ring-opening of 1,2-oxazetidines, this efficient protocol provides a facile and novel
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.
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.
Intramolecular Transamidation of Secondary Amides via Visible-Light-Induced Tandem Reaction
Tang, Li,Li, Xing-Meng,Matuska, Jack H.,He, Yan-Hong,Guan, Zhi
supporting information, p. 5618 - 5621 (2018/09/21)
Transformation of secondary amides to N-acylimines was used as an effective strategy to activate otherwise unreactive amide bonds. In this tandem reaction, the Rose Bengal-catalyzed photo-oxidative coupling of arylglycine esters and enamides generates N-acylimines, which undergo intramolecular transamidation and imine hydrolysis to afford bioactive acyl Mannich base derivatives under metal-free and mild conditions.
Iron-Catalyzed Radical Cycloaddition of 2H-Azirines and Enamides for the Synthesis of Pyrroles
Zhao, Mi-Na,Ren, Zhi-Hui,Yang, De-Suo,Guan, Zheng-Hui
supporting information, p. 1287 - 1290 (2018/03/09)
A novel and efficient Fe-catalyzed radical cycloaddition of 2H-azirines and enamides for the synthesis of substituted pyrroles has been developed. The radical cycloaddition reaction proceeded through a conceptually new Fe(II)-catalyzed homolytic cleavage of C-N bond of 2H-azirines sequential radical cyclization with enamides. The reaction used readily available starting materials, tolerated various functional groups, and afforded valuable triaryl-substituted pyrroles in good to high yields under mild reaction conditions.
