Preparation and regioselective reactions of novel gem-difluorinated vinyloxiranes with some organometallic reagents.
Hitherto unknown, relatively labile gem-difluorinated vinyloxiranes were prepared by difluoro-Wittig reactions with alpha,beta-epoxyketones; for these vinyloxiranes alkyl groups were delivered at the fluorine-attached terminal carbon atom in an SN2' manner by RLi, while Me3Al and MeMgBr-CuCl (3: 1) introduced the Me group at the allylic epoxy carbon with retention and inversion of the original stereochemistry, respectively.
Oxidative cross-coupling of beta,beta-difluoroenol silyl ethers with nucleophiles: a dipole-inversion method to difluoroketones.
Oxidative cross-coupling of alpha-aryl-beta,beta-difluoroenol silyl ethers with heteroaromatics in the presence of Cu(OTf)(2) in wet acetonitrile proceeds smoothly, affording heteroaryldifluoromethyl aryl ketones in 61-88% yields. Alcohols also react as nucleophiles under the same conditions to provide alkoxydifluoromethyl aryl ketones in 73-80% yields. [reaction: see text]
Students as promoters of rural extension in aquaculture in the Marajó archipelago, Pará, Brazil
Aquaculture is the creation of aquatic organisms. An expanding activity, being of great importance its approach in rural extension. Thus, the objective of this study was to analyze the contribution of extension activities in aquaculture in the professional training of students in Marajó, Amazon, Brazil. The project “Technology transfer through training and technical assistance for tambaqui breeders, Colossoma macropomum, in the archipelago of Marajó/PA” was developed by 10 technician and under graduate students from rural education course and the technical course in aquaculture from the Federal Institute of Education, Science and Technology of Pará (IFPA) Campus Breves, in the city of Curralinho. They participated in the stages of data collection in aquaculture enterprises, training for producers and monitoring of aquaculture production, acting as researchers, instructors and extension workers, respectively. The duration of the project was from August 2019 to March 2020. At the end of the project, a questionnaire was applied to the students involved. The results showed that the aquaculture extension activities developed were relevant and significant, for the construction of knowledge in a mutual way between those involved (students and aquaculture producers). The acquired experiences will substantiate and subsidize the professional practice of these students in a concrete and effective way. In conclusion, the extension project represents an excellent tool in the teaching-learning process for students.