- Regio- and diastereoselective synthesis of cyclic amino esters
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Several cyclic amino esters have been prepared regio- and diastereoselectively depending on the electrophile (cis or trans alkene) and its leaving group.
- Park, Kyung-Ho,Kurth, Thomas M.,Olmstead, Marilyn M.,Kurth, Mark J.
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- Tandem nucleophilic addition-cycloaddition of arynes with α-iminoesters: Two concurrent pathways to imidazolidines
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The tandem nucleophilic addition-cycloaddition reaction has been developed for the synthesis of functionalized imidazolidine derivatives. A variety of α-iminoesters and aryne precursors were well tolerated under the mild reaction conditions. This asymmetric cycloaddition afforded imidazolidine derivatives with high yields, complete regioselectivities, and excellent diastereo- and enantioselectivities. Aryne-induced ylides working as 1,3-dipoles for asymmetric cycloaddition are the notable feature of the present reaction. In the tandem reaction, the [3+2] cycloaddition of aryne-induced ylides with metallized α-iminoesters and metal-catalyzed [3+2] cycloaddition of azomethine ylide with α-iminoesters are two concurrent pathways to imidazolidines.
- Jia, Hao,Guo, Zhenyan,Liu, Honglei,Mao, Biming,Shi, Xueyan,Guo, Hongchao
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supporting information
p. 7050 - 7053
(2018/07/05)
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- Diastereoselective Trifluoroacetylation of Highly Substituted Pyrrolidines by a Dakin-West Process
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A robust approach allowing for the efficient trifluoroacetylation of a series of highly substituted pyrrolidines in a diastereoselective manner is reported. The transformation is based on a Dakin-West reaction of advanced pyrrolidine 2-carboxylic acid derivatives that can be assembled stereoselectively in four synthetic steps. Importantly, this work demonstrates how the introduction of lateral substituents on the pyrrolidine scaffold enables the generation of the desired trifluoroacetylation products, which was not possible previously due to the exclusive formation of trifluoromethylated oxazoles (vide infra). In the course of this work we succeeded for the first time in isolating and characterizing (HRMS, IR, 1H, 13C and 19F NMR, X-ray) different intermediates of the Dakin-West reaction allowing us to probe its mechanism.
- Baumann, Marcus,Baxendale, Ian R.
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p. 11898 - 11908
(2016/12/09)
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- Cu(I)-Catalyzed Highly Enantioselective [3 + 3] Cycloaddition between Two Different 1,3-Dipoles, Phthalazinium Dicyanomethanides and Iminoester-Derived Azomethine Ylides
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(Chemical Equation Presented). The Cu(I)-catalyzed highly enantioselective [3 + 3] cycloaddition between two different 1,3-dipoles, phthalazinium dicyanomethanides and iminoester-derived azomethine ylides, has been achieved under mild reaction conditions, providing novel chiral heterocyclic compounds, 2,3,4,11b-tetrahydro-1H-pyrazino[2,1-a]phthalazine derivatives, in high yields with excellent diastereo- and enantioselectivies (up to 99% yield, 99% ee, >20:1 dr).
- Yuan, Chunhao,Liu, Honglei,Gao, Zhenzhen,Zhou, Leijie,Feng, Yalin,Xiao, Yumei,Guo, Hongchao
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supporting information
p. 26 - 29
(2015/07/28)
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- Metal-catalyzed [6 + 3] cycloaddition of tropone with azomethine ylides: A practical access to piperidine-fused bicyclic heterocycles
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The first metal-catalyzed [6 + 3] cycloaddition of tropone with azomethine ylides has been developed. With the use of a chiral ferrocenylphosphine- copper(I) complex as the catalyst, the asymmetric variant of the [6 + 3] cycloaddition has also been successfully achieved. The reactions proceeded smoothly under mild conditions, affording piperidine-fused bicyclic heterocycles in moderate to high yields with good to excellent diastereo-and enantioselectivies. The procedures are operationally simple and the catalysts are cheap and readily accessible, thus providing a practical approach to piperidine-fused bicyclic heterocycles.
- Liu, Honglei,Wu, Yang,Zhao, Yan,Li, Zhen,Zhang, Lei,Yang, Wenjun,Jiang, Hui,Jing, Chengfeng,Yu, Hao,Wang, Bo,Xiao, Yumei,Guo, Hongchao
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supporting information
p. 2625 - 2629
(2014/03/21)
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- Enantioselective copper-catalyzed [3+3] cycloaddition of azomethine ylides with azomethine imines
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The more dipoles, the merrier: An asymmetric [3+3] cycloaddition of azomethine ylides derived from imines 1 with azomethine imines 2 in the presence of a chiral ferrocenylphosphine-copper catalyst afforded highly functionalized heterocyclic products 3 in high yield with excellent enantio- and diastereoselectivity (see scheme; DBU=1,8-diazabicyclo[5.4.0]undec-7-ene). The 1,3-dipolar reaction partners can be readily prepared from aldehydes. Copyright
- Guo, Hongchao,Liu, Honglei,Zhu, Fu-Lin,Na, Risong,Jiang, Hui,Wu, Yang,Zhang, Lei,Li, Zhen,Yu, Hao,Wang, Bo,Xiao, Yumei,Hu, Xiang-Ping,Wang, Min
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supporting information
p. 12641 - 12645
(2013/12/04)
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- Complete facial selectivity in the Diels-Alder reaction of a 5-amino-5-carboxycyclopentadiene derivative
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5-tert-Butoxycarbonylamino-5-carbethoxy-2-tert-butyldimethylsilyloxy- cyclopentadiene undergoes a Diels-Alder reaction exclusively from the face syn to the nitrogen functionality. Complete reversal of facial bias may be achieved, but at the cost of dimini
- Kim, Simon,Ciufolini, Marco A.
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supporting information; scheme or table
p. 3274 - 3277
(2011/08/05)
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- PhIO as a powerful cyclizing reagent: Regiospeciflc [3+2]-tandem oxidative cyclization of imine toward cofacially self-aggregated low molecular mass organic materials
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The powerful cyclization and tandem oxidation property of environmentally benign PhIO is developed for the first time, which leads to regiospecific [3+2]-tandem oxidative cyclization of imine at room temperature in rapid access to a new class of compounds
- Pandit, Palash,Chatteijee, Nirbhik,Halder, Samiran,Hota, Sandip K.,Patra, Amarendra,Maiti, Dilip K.
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supporting information; experimental part
p. 2581 - 2584
(2009/07/25)
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