An efficient oxidative NHC-catalyzed one-step transformation of (S)- or (R)-8-oxocitronellal to nepetalactone (NL) in enantio- and diastereomerically pure form has been developed. Several new and "easy to make" N-Mes- or N-Dipp-substituted 1,2,4-triazolium salts carrying nitroaromatic groups on N1 were synthesized and evaluated as precatalysts in combination with base and stoichiometric organic oxidant
Photocatalytic hydrofluoroalkylation of alkenes with carboxylic acids
作者:Kang-Jie Bian、Yen-Chu Lu、David Nemoto、Shih-Chieh Kao、Xiaowei Chen、Julian G. West
DOI:10.1038/s41557-023-01365-0
日期:2023.12
fluoroalkyl carboxylic acids as the sole reagents. Hydrotrifluoro-, difluoro-, monofluoro- and perfluoroalkylation are all demonstrated, with broad scope, mild conditions (redox neutral) and potential for late-stage modification of bioactive molecules. Critical to success is overcoming the exceedingly high redox potential of feedstock fluoroalkyl carboxylic acids such as trifluoroacetic acid by leveraging cooperative
We have developed a widely applicable (radio)fluoro-iodination of alkenes using readily available and easily handled KF (18F). The reactions exhibited high functional group tolerance and needed only an ambient atmosphere. Furthermore, the resulting product could be further functionalized with various nucleophiles.
Enhancement of antiproliferative activity by molecular simplification of catalpol
作者:Celina García、Leticia G. León、Carlos R. Pungitore、Carla Ríos-Luci、Antonio H. Daranas、Juan C. Montero、Atanasio Pandiella、Carlos E. Tonn、Víctor S. Martín、José M. Padrón
DOI:10.1016/j.bmc.2010.02.044
日期:2010.4
Two iridoid scaffolds were synthesized enantioselectively using as key step an L-proline-catalyzed alpha-formyl oxidation. The in vitro antiproliferative activities were evaluated against a representative panel of human solid tumor cell lines. Both iridoids induced considerably growth inhibition in the range 0.38-1.86 mu M. Cell cycle studies for these compounds showed the induction of cell cycle arrest at the G(1) phase. This result was consistent with a decrease in the expression of cyclin D1. Damaged cells underwent apoptosis as indicated by specific Annexin V staining. (C) 2010 Elsevier Ltd. All rights reserved.