Iron trichloride promotes the cationic cyclization of o-(arylethynyl)aryl isocyanates leading to 3-(arylchloromethylene)oxindoles which can be stereoselectively converted to (Z)-3-(aminomethylene)oxindoles under straightforward conditions. When the alkyne is substituted by an alkyl group, activation of the allylic C-H bond also occurs producing 1,2-(dichloroalkylidene)oxindoles.
We developed a concise synthetic method for benzotrifurans and benzotripyrroles from 1,3,5-triethynyl-2,4,6-trifluorobenzenes by one-pot reactions in good to excellent yield. By investigating 2-D and 3-D structures of a variety of benzotrifuran and benzotripyrrole derivatives using scanning tunneling microscopy (STM) and single-crystal X-ray diffraction techniques, we found both similarities and dissimilarities. We also found that diverse molecular 3-D orientations were derived in their single crystals according to substituents on the molecules and that the emission properties in the solid state are dependent on their packing manners.
State. -An interesting synthesis of 2,5,8-trisubstituted benzotrisfurans and analogous benzotrispyrroles is developed using the base promoted reaction of triethynyltrifluorobenzenes (I) and (III) with water or primary amines. The structure of the solid materials generated by the products is studied by scanning tunneling microscopy and single x-ray diffraction techniques. -(TSUJI*, H.; CANTAGREL, G.; UEDA, Y.; CHEN, T.; WAN, L.-J.; NAKAMURA, E.; Chem. -Asian J. 8 (2013) 10, 2377-2382, http://dx.
Hydrogenation O 0220Hydrogenation versus Hydrogenolysis with a Safe, Selective and Reusable Catalyst: Palladium Black on Teflon. -The palladium-coated teflon magnetic stirring bar is used as a hydrogenation catalyst for a variety of substituted alkenes and alkynes affording saturated products in high yields. No deprotection occurs during the reaction. Disubstituted olefins with polar nucleophilic groups and substrates (XII) and (XIII) are unreactive. The catalyst can be reused for 4 times without any catalytic loss. No trace of palladium is found in the hydrogenation solutions. -(BELOTTI, D.; CANTAGREL*, G.; COMBELLAS, C.; COSSY, J.; KANOUFI, F.; NUNIGE, S.; New J. Chem. 29 (2005) 6, 761-764; Lab. Chim. Org., CNRS, Ec. Super. Phys. Chim. Ind., F-75231 Paris, Fr.; Eng.) -Y. Steudel 44-058
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