In the presence of BFyOEta, (perfluoroalkyl)lithiums generated in situ from the reaction of primary perfluoroalkyl iodides and MeLi-LiBr reacted with imines, azines, and nitrones to afford perfluoroalkylated nitrogen-containing compounds in moderate to good yields. This method was successfully applied to the preparation of a (perfluoroalkyl)glycine and optically active perfluoroalkylated amines.Methodology for introducing the perfluoroalkyl group into organic molecules has recently been developed greatly due to increasing needs for fluorine-containing compounds in a variety of industrial fields. These methods can be conveniently divided into three types: cationic perfluoroalkylation represented by the reactions of Umemoto's FITS ((perfluoroalkyl)phenyliodonium trifluoromethanesulfonates) reagents;1 2 addition of perfluoroalkyl radicals generated from perfluoroalkyl halides,3 perfluoroalkanoyl peroxides,4 or other perfluoroalkyl sources;5 and nucleophilic or coupling reactions of (perfluoroalkyl)metals represented by (perfluoroalkyl)zinc6 and (perfluoroalkyl)copper reagents.7 In the last type of reaction, difficulties are often encountered due to the instability and low reactivity of these metal reagents. Perfluoroalkyl Grignard and lithium reagents react with carbonyl compounds8 such as aldehydes, ketones, and esters, but they fail to react with less polarized functional groups, leading to self-decompo-

Wedelia chinensis (Asteraceae) is a wetland herb native to India, China, and Japan. It is a valuable medicinal plant recorded to have pharmaceutical properties. However, the phytotoxic potential of Wedelia chinensis has not yet been examined. Thus, we carried out this study to establish the allelopathic effects of Wedelia chinensis and to identify its phytotoxic substances. Extracts of Wedelia chinensis exhibited high inhibitory activity against the root and shoot growth of cress, alfalfa, rapeseed, lettuce, foxtail fescue, Italian ryegrass, timothy, and barnyard grass. The inhibition was varied with species and was dependent on concentrations. The extracts were separated through several purification steps, and the two effective substances were isolated and characterized as vanillic acid and gallic acid using spectral analysis. Vanillic acid and gallic acid significantly arrested the growth of cress and Italian ryegrass seedlings. The concentrations of vanillic acid and gallic acid needed for 50% inhibition (I50 values) of the seedling growth of the cress and Italian ryegrass were 0.04–15.4 and 0.45–6.6 mM, respectively. The findings suggest that vanillic acid and gallic acid may be required for the growth inhibitory activities of Wedelia chinensis.

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