1011269-13-8Relevant articles and documents
Catalyst-Free [4+2] Cycloaddition of Ynamides with 2-Halomethyl Phenols to Construct 2-Amino-4 H-Chromenes and α-Halo Enamides Simultaneously
Wen, Hao,Yan, Weibo,Chen, Ping,Li, Yu,Tang, Yu
, p. 12870 - 12881 (2020)
We report the development of a facile protocol for the [4+2] cycloaddition of ynamides and 2-halomethyl phenols to afford the corresponding 2-amino-4H-chromenes and α-halo enamides under catalyst-free conditions. The reaction proceeds under mild condition
Base-Mediated Generation of Ketenimines from Ynamides: [3+2] Annulation with Azaallyl Anions
D'Hollander, Agathe C. A.,Romero, Eugénie,Vijayakumar, Kamsana,Le Houérou, Camille,Retailleau, Pascal,Dodd, Robert H.,Iorga, Bogdan I.,Cariou, Kevin
, p. 2903 - 2908 (2021/04/21)
Under basic conditions and heat, ynamides can serve as precursors to ketenimines, whose synthetic potential is often hampered by their difficulty of access. Herein, we report that they can undergo a [3+2] cycloaddition with 2-azaallyl anions, obtained from benzylimines under the same reaction conditions. This reaction between two highly reactive intermediates, both generated in situ from bench stable starting materials, gives access to various nitrogen-rich heterocycles. The reaction usually proceeds with excellent diastereoselectivity, in favor of the cis adduct. Deuteration experiments and DFT calculations helped rationalize the regio- and stereoselectivity of the process as well as the formation of side products. (Figure presented.).
A Unified Approach for Divergent Synthesis of Heterocycles via TMSOTf-Catalyzed Formal [3+2] Cycloaddition of Electron-Rich Alkynes
Chen, Ping,Cao, Wei,Li, Xiangqian,Shi, Dayong
, p. 4789 - 4794 (2021/09/02)
We present a synthetic protocol for the construction of polysubstituted five-membered heterocycles via TMSOTf-catalyzed formal [3+2] cycloaddition of electron-rich alkynes, which features free from any metal, atom economy and water as the main by-product. Furthermore, alkenyl ether adduct has been verified as the key intermediate. Notably, by utilizing this approach, we can synthesize a broad range of polysubstituted furans, thiophenes and pyrroles, and extend this transformation to deliver fused-polyheterocycles. This reaction can be achieved on a gram scale and the corresponding products are intermediates for producing diverse potentially useful scaffolds. (Figure presented.).
Method for efficiently preparing alkynamide compounds
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Paragraph 0059-0061, (2019/02/21)
The invention discloses a general method for efficient preparation of alkynamide compounds. The method uses secondary amine with an electron-withdrawing group (EWG) and 1, 1-dichloroethylene, 1, 2-dichloroethylene or bis-dichloroarylethylene as a raw mate
Metal-free hydration of ynamides: Convenient approach to amides
Huang, Hai,Tang, Luning,Xi, Yang,He, Guangke,Zhu, Hongjun
supporting information, p. 1873 - 1876 (2016/04/19)
The trifluoroacetic acid (TFA) mediated hydration of ynamides was developed, which is an efficient approach for the synthesis of N-monosubstituted amides. This convenient method is effective with a wide range of substrates under room temperature condition, and the products are obtained in high to excellent yields through an easy work-up process.
Synthesis of functionalized oxazolones by a sequence of Cu(ll)- And Au(l)-catalyzed transformations
Istrate, Florin M.,Buzas, Andrea K.,Jurberg, Igor Dias,Odabachian, Yann,Gagosz, Fabien
supporting information; experimental part, p. 925 - 928 (2009/04/07)
A study concerning a two-step sequence leading to the formation of diversely 1,5-disubstituted oxazolones is described. The mild conditions employed allow the efficient and rapid synthesis of a variety of such compounds via an initial Cu(II)-catalyzed coupling of a bromoalkyne with a secondary tert-butyloxycarbamate followed by a Au(l)-catalyzed cycloisomerization of the N-alkynyl tert-butyloxycarbamates thus obtained.
