[reaction: see text] Selective and effective fluorination of various types of organic compounds performed in water as the reaction medium using 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor F-TEDA-BF4) is reported. 2-Naphthole and 2-methoxynaphthalene were thus transformed to 1,1-difluoro-2(1H)naphthalenone, estrone to 10beta-fluoro-1,4-estradien-3,17-dione, phenyl-substituted alkenes to vicinal fluorohydrins, and various ketones, 1,3-diketones, or beta-ketoesters to corresponding alpha-fluoro or alpha,alpha-difluoro ketones.
We present a general protocol for processing cost‐beneficial, environmentally benign aqueous‐type suspensions containing metal‐oxide nanostructured particles, and their patterning with piezoelectric ink‐jet printing technology. The critical issues relevant to ink‐jet printing are the preparation and stabilization of nanosized particles in a fluid and adjusting its physical properties to the values appropriate for a particular ink‐jet printer mechanism. We discuss and illustrate, on a model titania system, the processing of a highly stable, colloidal, water‐based suspension containing particles not bigger than 570 nm, prepared by a ball‐milling process. For the ink‐jet printing experiments, the surface tension and the viscosity of the suspension were modified by the addition of a small amount of the appropriate non‐ionic amphiphiles and glycerol. The formation of droplets, their positioning on the substrate, and the shape and uniformity of the dots on the substrate are discussed and correlated with the fluid properties via the inverse Ohnesorge number Z. It was shown successfully that uniform, regular‐shaped TiO2 dots with a diameter of 30 μm and a good positioning accuracy on Si/SiO2 substrates could be obtained by jetting a fluid with Z values of 5 and 9 using a piezoelectric ink‐jet printer with a nozzle diameter of 21 μm operating at an amplitude of 13 V and a frequency of 5 kHz.
Selective and efficient iodinations of organic compounds were achieved by an aerobic oxidative process catalyzed by sodium nitrite using potassium iodide in acidic media. Using the potasasium iodide (KI)/air/sodium nitrite (NaNO 2 ; cat.)/sulfuric acid (H 2 SO 4 ) iodinating system, activated and moderately deactivated aromatic compounds were exclusively or preferentially iodinated at the para position. In protic solvents ketones and 1,3-dicarbonyl compounds were iodofunctionalized at the a carbonyl position, while in the case of aryl methyl ketones bearing an activated aromatic ring, the regioselectivity of iodination could be directed by the solvent used. In acetonitrile (MeCN) the aromatic ring was selectively iodinated, while in aqueous rethanol (EtOH) functionalization of the methyl carbon atom took place. Alkenes were transformed to vicinal iodohydrins or vicinal iodoalkoxy derivatives following Markovnikov-type regioselectivity and anti stereoselectivity, while 1,2-diiodoalkenes with preferentially E orientation were formed from alkynes.
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