Geochemistry of arsenic and selenium in a Ge-poor coal from the Wulantuga coal-hosted Ge ore deposit,Inner Mongolia,North China

This paper reports new data for arsenic(As)and selenium(Se)in a total of twelve bench samples of Ge-rich and Ge-poor coals in the No.6 coal seam from the Wulantuga ore deposit,Inner Mongolia,Northeastern China.The Gepoor coals are characterized by low-ash(with a weighted average ash yield 10.59%).The coal samples were digested using an UltraClave microwave high pressure reactor(milestone)and trace elements were detected by inductively coupled plasma mass spectrometry—collision/reaction cell technology,a reliable method for As and Se determination in coal samples.The contents of As and Se in the Ge-poor(with a weighted average content of 9.14 and 0.30 lg/g,respectively)and Ge-rich coal samples in the present study(varies from 16.88 to 17,776 lg/g and from 0.26 to 14.39 lg/g,respectively)are in a sharp contrast.The As in the Ge-poor coals is of both organic-and pyrite-associations,and its enrichment is attributed to the sediment source,and to a lesser extent,to hydrothermal fluids.Se is predominantly connected with organic matter in the Wulantuga Ge-poor coals.

Fluorine-containing agrochemicals in the last decade and approaches for fluorine incorporation

In this review, the methodologies for fluorine incorporation of 40 fluorine-containing agrochemicals that received an international standardization organization(ISO) name during the last decade are described.The predominant approach for fluorine introduction of these agrochemicals is to use a fluorine-containing building block. Here we present how the fluorine-containing building blocks are introduced into these agrochemicals. The synthetic methods of fluorine-containing building blocks that are not easily available are also specifically discussed. Fluoroarenes, difluomethylarenes and trifluomethylarenes are the main building blocks that have been used in this review. Fluorine-containing small molecules, such as alcohol,amine, ketoester, olefin are also widely used. The only example of late-stage fluorination is the synthesis of fungicide quinofumelin. We believe the fluorine introduction methods described here can provide ideas for the development of new and economical pesticide synthetic routes, and stimulate researchers to develop new fluorine incorporation methods and create new pesticides.

Studies on the biological activity of gem-difluorinated 3,3-spirocyclic indole derivatives

The biological activities of a series of 3,3-spirocyclic indole derivatives containing CF_(2), phosphine oxide,indole, and cyano functional groups were evaluated, and these derivatives were found to exhibit antiTMV, fungicidal, and insecticidal activities.

Decatungstate as a direct hydrogen atom transfer photocatalyst for synthesis of trifluromethylthioesters from aldehydes

We have developed a versatile,mild protocol for trifluoromethylthiolation reactions of aldehydes with catalysis by a decatungstate hydrogen atom transfer photocatalyst under redox-neutral conditions.The protocol is highly selective,operationally simple,and compatible with a wide array of sensitive functional groups.It can be used for late-stage functionalization of bioactive molecules,which makes it convenient for drug discovery.

ROUTE DEVELOPMENT, ANTIVIRAL STUDIES, FIELD EVALUATION AND TOXICITY OF AN ANTIVIRAL PLANT PROTECTANT NK0238

It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identification of NK0238as a highly effective agent for the prevention and control of diseases caused byplant viruses, but the existing routes are unsuitable for its large-scale synthesis.This study optimized a route for two-step synthesis of this virucide candidate viareaction of L-tryptophan with triphosgene to produce L-tryptophan-N-carboxylicanhydride, which then reacts with n-octylamine to give NK0238 at up to 94%yield and nearly 97% HPLC purity. In addition, the route was used for thepreparation of NK0238 on a > 40 g scale permitting further assessment of itsantivirus activity in the greenhouse and field experiments, and toxicity tests.NK0238 exhibited useful antiviral activities against a variety of viruses both ingreenhouse and field experiments. The toxicity tests showed that NK0238 wasnot acutely toxic to birds, fish, honey bees and silkworms. The optimized routeprovides a solid foundation for its large-scale synthesis and subsequent efficacyand toxicity studies, its excellent activity and safety make NK0238 a promisingdrug candidate for further development.

Rh(Ⅲ)-catalyzed C8 arylation of quinoline N-oxides with arylboronic acids

Herein,we report the first Rh~Ⅲ-catalyzed regioselective C8 arylation of quinoline N-oxides with commercially available arylboronic acids as coupling partners.This procedure is simple,and the reaction shows perfect regioselectivity,a broad substrate scope,and isolated yields of up to 92%.We demonstrate the utility of the reaction by using it for late-stage functionalization of a fungicide.