860190-31-4Relevant academic research and scientific papers
Catalytic Generation of Donor-Acceptor Cyclopropanes under N-Heterocyclic Carbene Activation and their Stereoselective Reaction with Alkylideneoxindoles
Prieto, Liher,Sánchez-Díez, Eduardo,Uria, Uxue,Reyes, Efraím,Carrillo, Luisa,Vicario, Jose L.
, p. 1678 - 1683 (2017)
Formylcyclopropanes undergo activation in the presence of an N-heterocyclic carbene catalyst generating a donor-acceptor cyclopropane intermediate with the ability to undergo ring-opening followed by formal [4+2] cycloaddition with alkylideneoxindoles. This enables the direct enantio- and diastereoselective synthesis of tetrahydropyrano[2,3-b]indoles through the use of a chiral NHC catalyst. (Figure presented.).
Stereoselective Organocatalytic Construction of Spiro Oxindole Pyrrolidines Using Unsaturated α-Ketoesters and α-Ketoamides
Peňa?ka, Tibor,Palchykov, Vitalii,Rakovsky, Erik,Addová, Gabriela,?ebesta, Radovan
supporting information, p. 1693 - 1703 (2021/03/15)
We have investigated the stereoselective formation of spiro oxindole pyrrolidines via formal [3+2] cycloaddition of oxindole imines with ketoesters and ketoamides. Bifunctional squaramide organocatalyst was able to induce enantioselectivity of up to 60 %
Diversity-Oriented Synthesis of Spirocyclohexene Indane-1,3-diones and Coumarin-Fused Cyclopentanes via an Organobase-Controlled Cascade Reaction
Wang, Min,Tseng, Ping-Yao,Chi, Woei-Jye,Suresh, Sundaram,Edukondalu, Athukuri,Chen, Yi-Ru,Lin, Wenwei
supporting information, p. 3407 - 3415 (2020/07/16)
An organobase-controlled, divergent cascade reaction to construct spirocyclohexene indane-1,3-diones and coumarin-fused cyclopentanes is reported. The cascade reaction is triggered by the 1,6-addition of 3-homoacylcoumarins to the indanedione-derived acce
Photoactivity hexahydroquinolinone and preparation method thereof
-
Paragraph 0057; 0170-0172, (2017/07/21)
The invention discloses photoactivity hexahydroquinolinone and a preparation method thereof. The photoactivity hexahydroquinolinone is a diastereoisomer consisting of a compound shown as a formula I and a compound shown as a formula II, wherein a diastere
Boosting Chemical Stability, Catalytic Activity, and Enantioselectivity of Metal-Organic Frameworks for Batch and Flow Reactions
Chen, Xu,Jiang, Hong,Hou, Bang,Gong, Wei,Liu, Yan,Cui, Yong
supporting information, p. 13476 - 13482 (2017/10/05)
A key challenge in heterogeneous catalysis is the design and synthesis of heterogeneous catalysts featuring high catalytic activity, selectivity, and recyclability. Here we demonstrate that high-performance heterogeneous asymmetric catalysts can be engineered from a metal-organic framework (MOF) platform by using a ligand design strategy. Three porous chiral MOFs with the framework formula [Mn2L(H2O)2] are prepared from enantiopure phosphono-carboxylate ligands of 1,1′-biphenol that are functionalized with 3,5-bis(trifluoromethyl)-, bismethyl-, and bisfluoro-phenyl substituents at the 3,3′-position. For the first time, we show that not only chemical stability but also catalytic activity and stereoselectivity of the MOFs can be tuned by modifying the ligand structures. Particularly, the MOF incorporated with -CF3 groups on the pore walls exhibits enhanced tolerance to water, weak acid, and base compared with the MOFs with -F and -Me groups. Under both batch and flow reaction systems, the CF3-containing MOF demonstrated excellent reactivity, selectivity, and recyclability, affording high yields and enantioselectivities for alkylations of indoles and pyrrole with a range of ketoesters or nitroalkenes. In contrast, the corresponding homogeneous catalysts gave low enantioselectivity in catalyzing the tested reactions.
A New Strategy for Enantioselective Construction of Multisubstituted Five-Membered Oxygen Heterocycles via a Domino Michael/Hemiketalization Reaction
Hua, Yuan-Zhao,Liu, Meng-Meng,Huang, Pei-Jin,Song, Xixi,Wang, Min-Can,Chang, Jun-Biao
supporting information, p. 11994 - 11998 (2015/08/18)
A new highly enantioselective domino Michael/hemiketalization reaction of α-hydroxyacetophenone with β,γ-unsaturated α-keto esters for the synthesis of 2,2,4,5-tetrasubstituted chiral tetrahydrofurans is reported. With 2 mol% intramolecular dinuclear zinc
Enantioselective copper(I/II)-catalyzed conjugate addition of nitro esters to β,γ-unsaturated α-ketoesters
Zhang, Sheng,Xu, Kun,Guo, Fengfeng,Hu, Yanbin,Zha, Zhenggen,Wang, Zhiyong
supporting information, p. 979 - 982 (2014/02/14)
A highly enantioselective Michael addition of nitroacetates to β,γ-unsaturated α-ketoesters was developed by using chiral copper catalysts. The Michael addition products can be obtained in high yields with up to 99 % ee. With these densely functionalized products, the chiral cyclic nitrones, which are important synthetic intermediates, can be obtained in one step. Copyright
Enantioselective copper-catalyzed conjugate addition of trimethylaluminium to β,γ-unsaturated α-ketoesters
Gremaud, Ludovic,Alexakis, Alexandre
supporting information; experimental part, p. 794 - 797 (2012/03/09)
Not a cop out: The copper-catalyzed asymmetric conjugate addition of organometallic reagents to Michael acceptors is an important methodology for forming a C-C bond in an enantioselective manner. Such an addition of Me 3Al to β,γ-unsaturated α-
