A cheap, mild, fast, and environmentally friendly oxidation of olefins to the corresponding epoxides is reported using polyfluoroalkyl ketones as efficient organocatalysts. Namely, 2,2,2-trifluoroacetophenone was identified as an improved organocatalyst for the epoxidation of alkenes. Various olefins, mono-, di-, and trisubstituted, are epoxidized chemoselectively in high to quantitative yields utilizing 2-5 mol % catalyst loading and H2O2 as the green oxidant.
The oxidation of organosilanes to silanols constitutes an attractive transformation for both industry and academia. Bypassing the need for stoichiometric oxidants or precious metal catalytic complexes, the first organocatalytic oxidation of silanes has been accomplished. Catalytic amounts of 2,2,2-trifluoroacetophenone, in combination with the green oxidant H 2 O 2 , lead to excellent to quantitative yields in a short reaction time. A variety of alkyl, aryl, alkenyl, and alkynyl substituents can be tolerated, providing an easy, cheap, efficient, and practical solution to a highly desirable transformation.
The regulation of the catalytic activity of the various phospholipase A enzymes is of high importance because these enzymes are involved in various pathological conditions such as arthritis, cardiovascular diseases, neurological diseases, and cancer. Thus, a great effort has been devoted in developing synthetic inhibitors as new agents to treat inflammatory diseases. Some of them have reached clinical trials. Areas covered: This review article discusses the phospholipase A inhibitors presented in patent literature from October 2012 to June 2016, their activities in vitro and in vivo as well as the results of clinical trials using synthetic PLA inhibitors. Expert opinion: None of the inhibitors studied in clinical trials have reached the market yet. The failure of lipoprotein-associated PLA inhibitor darapladib to reduce the risk of major coronary events suggests that this enzyme may be a biomarker of vascular inflammation rather than a causal pathway of cardiovascular diseases. These findings, together with the failure of secreted PLA inhibitor varespladib for the treatment of cardiovascular disease, indicate that deeper knowledge on these enzymes is needed. Inhibitors of cytosolic PLA are in clinical trials against psoriasis and atopic dermatitis.
The development of inhibitors for phospholipases A2 (PLA2s) is important in elucidating their implication in various biological pathways. PLA2 enzymes are an important pharmacological target implicated in various inflammatory diseases. Computational chemistry, organic synthesis and in vitro assays were employed to develop potent and selective inhibitors for Group VIA calcium-independent PLA2. A set of fluoroketone inhibitors, were studied for their binding mode with two human cytosolic PLA2 enzymes: Group IVA cPLA2 and Group VIA iPLA2. New compounds were synthesized and tested against three major PLA2 enzyme. This study led to the development of four potent and selective thioether fluoroketone inhibitors as well as a thioether keto-1,2,4-oxadiazole inhibitor for GVIA iPLA2, which will serve as lead compounds for future development and studies. The keto-1,2,4-oxadiazole functionality with a thioether is a novel structure and it will be used as a lead to develop inhibitors with higher potency and selectivity towards GVIA iPLA2.
A cheap, mild and environmentally friendly oxidation of tertiary amines and azines to the corresponding N-oxides is reported by using polyfluoroalkyl ketones as efficient organocatalysts. 2,2,2-Trifluoroacetophenone was identified as the optimum catalyst for the oxidation of aliphatic tertiary amines and azines. This oxidation is chemoselective and proceeds in high-to-quantitative yields utilizing 10 mol % of the catalyst and H2 O2 as the oxidant.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.