An Enantioselective Claisen Rearrangement Catalyzed by N-Heterocyclic Carbenes
作者:Juthanat Kaeobamrung、Jessada Mahatthananchai、Pinguan Zheng、Jeffrey W. Bode
DOI:10.1021/ja103631u
日期:2010.7.7
of a chiral azolium salt (10 mol %), enols and ynals undergo a highly enantioselective annulation reaction to form enantiomerically enriched dihydropyranones via an N-heterocycliccarbene catalyzed variant of the Claisen rearrangement. Unlike other azolium-catalyzed reactions, this process requires no added base to generate the putative NHC-catalyst, and our investigations demonstrate that the counterion
Applications of Thermal Activation, Ball-milling and Aqueous Medium in Stereoselective Michael Addition of Nitromethane to Enynones Catalyzed by Chiral Squaramides
作者:Żaneta A. Ignatiuk、Mikołaj J. Janicki、Robert W. Góra、Krzysztof Konieczny、Rafał Kowalczyk
DOI:10.1002/adsc.201801498
日期:2019.3.5
to conjugated en‐ynones was performed through the application of chiral squaramides. Three non‐classical approaches to promote the addition reaction were tested, including activation of the nucleophile by inorganic base in a biphasic aqueous system, thermal activation, and ball‐milling. Hydrogen‐bonding catalysis was effective in all these methods, providing 1,4‐addition products in high yields and
3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors. I. Structural modification of 5-substituted 3,5-dihydroxypentanoic acids and their lactone derivatives
作者:G. E. Stokker、W. F. Hoffman、A. W. Alberts、E. J. Cragoe、A. A. Deana、J. L. Gilfillan、J. W. Huff、F. C. Novello、J. D. Prugh
DOI:10.1021/jm00381a014
日期:1985.3
A series of 5-substituted 3,5-dihydroxypentanoic acids and their derivatives have been prepared and tested for inhibition of HMG-CoA reductase in vitro. In general, unless a carboxylate anion can be formed and the hydroxy groups remain unsubstituted in an erythro relationship, inhibitory activity is greatly reduced. Furthermore, only one enantiomer of the ring-opened form of lactone 6a(+/-) possesses
Nicholas Reactions of Pentadiynyl–Co2(CO)6 Cations. Synthesis of Antimalarial Hinokiresinol Analogues
作者:James R. Green、Marcus Muresan
DOI:10.1055/a-2250-8050
日期:2024.5
4-)diyne complexes. The compatible nucleophiles have a wide range of reactivity. The methodology has been applied to the synthesis of both (E)- and (Z)-isomers of a hinokiresinol and nyasol analogue, the (E)-isomer of which is known to have elevated antiplasmodial and antimalarialactivity.
Penta-1,4-diyn-3-ol–Co 2 (CO) 6配合物在 C-3 位点发生路易斯酸介导的尼古拉斯反应,具有高选择性,得到跳过的 (1,4-)二炔配合物。相容的亲核试剂具有广泛的反应活性。该方法已应用于合成hinokiresinol 和 nyasol 类似物的( E )-和 ( Z )-异构体,已知其 ( E )-异构体具有升高的抗疟原虫和抗疟活性。