AbstractAn enantioselective protonation by means of chiral scandium complex‐catalyzed aza‐Michael reaction was realized. A series of α‐aryl‐substituted vinyl ketones reacted with pyrazoles smoothly, affording the corresponding enantiomerically enriched pyrazole derivatives with excellent results (up to 99% yield, 94% ee). Water and hydrogen chloride were found to accelerate the protonation process.magnified image
Synthesis, Biological Properties, and Molecular Modeling Investigations of Novel 3,4-Diarylpyrazolines as Potent and Selective CB<sub>1</sub> Cannabinoid Receptor Antagonists
作者:Jos H. M. Lange、Hein K. A. C. Coolen、Herman H. van Stuivenberg、Jessica A. R. Dijksman、Arnoud H. J. Herremans、Eric Ronken、Hiskias G. Keizer、Koos Tipker、Andrew C. McCreary、Willem Veerman、Henri C. Wals、Bob Stork、Peter C. Verveer、Arnold P. den Hartog、Natasja M. J. de Jong、Tiny J. P. Adolfs、Jan Hoogendoorn、Chris G. Kruse
DOI:10.1021/jm031019q
日期:2004.1.1
novel 3,4-diarylpyrazolines was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The 3,4-diarylpyrazolines elicited potent in vitro CB(1) antagonistic activities and in general exhibited high CB(1) vs CB(2) receptor subtype selectivities. Some key representatives showed potent pharmacological in vivo activities after oral dosing in both a CB agonist-induced blood pressure
A novel enantioselective protonation protocol that is triggered by reductive cross coupling of olefins is reported. When under cooperative photoredox and chiral hydrogen-bonding catalytic conditions and using a terminal reductant, various α-branched vinylketones with diverse vinylazaarenes could provide important enantioenriched azaarene derivatives containing tertiary stereocenters at their remote
achieved by an organocatalysed aza-Michael/transimination domino sequence between hydrazones and enones making use of a mixture of heterogeneous resin-bound acid/base reagents. This methodology nicely illustrates the site isolation concept of supported reagents allowing the simultaneous use of otherwise destructive reactive functionalities.
Formal Enone α-Arylation via I(III)-Mediated Aryl Migration/Elimination
作者:Bruna S. Martins、Daniel Kaiser、Adriano Bauer、Irmgard Tiefenbrunner、Nuno Maulide
DOI:10.1021/acs.orglett.1c00251
日期:2021.3.19
A formal enone α-arylation is described. This metal-free transformation relies on the I(III)-mediated skeletal reorganization of silyl enol ethers and features mild conditions, good yields, and high stereoselectivities for β-substituted enones.
hydroacylation of α-substituted α,β-unsaturated carbonyl compoundsthrough direct hydrogen atom transfer in the presence of the photocatalyst anthraquinone and chiral N,N′-dioxide/metal complexes. This mild, robust method provided a facile access to a wide array of chiral ketones with α-tertiary stereocenters by using the readily available aldehyde as a hydroacylation reagent. Based on the spectroscopy experiments