- Catalytic Enantio- and Diastereoselective Mannich Addition of TosMIC to Ketimines
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Chiral amines bearing a stereocenter in the α position are ubiquitous compounds with many applications in the pharmaceutical and agrochemical sectors, as well as in catalysis. Catalytic asymmetric Mannich additions represent a valuable method to access such compounds in enantioenriched form. This work reports the first enantio- and diastereoselective addition of commercially available p-toluenesulfonylmethyl isocyanide (TosMIC) to ketimines, affording 2-imidazolines bearing two contiguous stereocenters, one of which is fully-substituted, with high yields and excellent stereocontrol. The reaction, catalyzed by silver oxide and a dihydroquinine-derived N,P-ligand, is broad in scope, operationally simple, and scalable. Derivatization of the products provides enantioenriched vicinal diamines, precursors to NHC ligands and sp3-rich heterocyclic scaffolds. Computations are used to understand catalysis and rationalize stereoselectivity.
- Franchino, Allegra,Chapman, Jack,Funes-Ardoiz, Ignacio,Paton, Robert S.,Dixon, Darren J.
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supporting information
p. 17660 - 17664
(2018/11/10)
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- Synthesis of Substituted Pyrroles via Copper-Catalyzed Cyclization of Ethyl Allenoates with Activated Isocyanides
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A new method for the synthesis of di- and trisubstituted pyrroles via copper-catalyzed cyclization of ethyl allenoates with activated isocyanides has been developed. In contrast to related annulation reactions previously reported, this new process features a skeletal rearrangement in which the aryl sulfonyl moiety, which functions as the electron-withdrawing group in the α-carbon of the isocyanide, was found to migrate to the γ-carbon of the starting allenoate in the final product for the first time.
- Lu, Kui,Ding, Fang,Qin, Long,Jia, Xiaoliang,Xu, Chuanming,Zhao, Xia,Yao, Qingwei,Yu, Peng
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supporting information
p. 2121 - 2125
(2016/08/12)
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- One-pot Van Leusen synthesis of 4,5-disubstituted oxazoles in ionic liquids
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An efficient and mild protocol for the preparation of 4,5-disubstituted oxazoles through an improved one-pot van Leusen oxazole synthesis in ionic liquids is described. The oxazole products were prepared from tosylmethyl isocyanide (TosMIC), aliphatic hal
- Wu, Bo,Wen, Jun,Zhang, Ji,Li, Jing,Xiang, Yong-Zhe,Yu, Xiao-Qi
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experimental part
p. 500 - 504
(2009/08/07)
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- Synthesis and structure-activity relationship of a new series of COX-2 selective inhibitors: 1,5-Diarylimidazoles
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The synthesis and the pharmacological activity of a series of 1,5-diarylimidazoles developed as potent and selective cyclooxygenase-2 (COX-2) inhibitors are described. The new compounds were evaluated both in vitro (COX-1 and COX-2 inhibition in human whole blood) and in vivo (carrageenan-induced paw edema, air-pouch, and hyperalgesia tests). Modification of all the positions of two regioisomeric imidazole cores led to the identification of 4-[4-chloro-5-(3-fluoro4-methoxyphenyl)imidazol-1-yl]benzenesulfonamide (UR-8880, 51f) as the best candidate, which is now undergoing Phase I clinical trials.
- Almansa, Carmen,Alfón, José,De Arriba, Alberto F.,Cavalcanti, Fernando L.,Escamilla, Ignasi,Gómez, Luis A.,Miralles, Agustí,Soliva, Robert,Bartrolí, Javier,Carceller, Elena,Merlos, Manuel,García-Rafanell, Julián
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p. 3463 - 3475
(2007/10/03)
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