Catalytic asymmetric conjugate addition of Grignard reagents to chromones
作者:Carlos Vila、Valentín Hornillos、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1039/c3cc43105c
日期:——
highly regio- and enantioselective copper catalysed direct conjugateaddition of Grignard reagents to chromones has been developed taking advantage of the reduced reactivity of the resulting magnesium enolates. This methodology tolerates a broad scope of alkyl Grignards including secondary alkyl magnesium reagents as well as functionalised chromones.
Regio- and Stereoselective Cyclization Reactions of Unsaturated Silyl Enol Ethers by Photoinduced Electron Transfer – Mechanistic Aspects and Synthetic Approach
作者:Sandra Hintz、Jochen Mattay、Rudi van Eldik、Wen-Fu Fu
various silyl enol ethers and silyloxy-2H-chromones bearing an olefinic or silylacetylenic side chain, The reactions result in regioselective ring closure with the formation of bi- to tetracyclic ring systems with a well-defined ring juncture, e.g. perhydrophenanthrenones 13 or benzo-annellated xanthenones 24. Our investigations have focussed on the optimization of this cyclization method with regard
Antituberculosis agent diaportheone B: synthesis, absolute configuration assignment, and anti-TB activity of its analogues
作者:Pandrangi Siva Swaroop、Gajanan N. Raut、Rajesh G. Gonnade、Priyanka Verma、Rajesh S. Gokhale、D. Srinivasa Reddy
DOI:10.1039/c2ob25831e
日期:——
fungus Diaporthe sp. P133 is reported using two complementary routes, a one step and a three-step sequence. The absolute configuration of diaportheone B was determined by using X-ray crystal structure analysis of its dibromo derivative. In addition, we have prepared several close analogues of diaportheone B and determined their anti-TB potential using Alamar-blue assay (H37Rv).