نتایج جستجو برای: 6 disubstituted 1
تعداد نتایج: 3240689 فیلتر نتایج به سال:
Emissions from fossil fuel combustion pose a serious threat to public health and =pose the need for animproved monitoring of polycyclic aromatic hydrocarbons (PARS), a major class of persistent organicpollutants. For this purpose the present study reports an investigation of the electronic structure of Pyrene byuse of different chemical models We also made a comparison between different chemica...
Herein, we report the first palladium/MPAA catalyzed enantioselective C-H activation/[4+1] annulation of diarylmethyltriflamide and olefins to construct chiral cis-1,3-disubstituted isoindoline derivatives. The use readily accessible mono N-protected amino acid...
The asymmetric hydrovinylation (1 mol % Ni-cat., 1 atm, ethylene, >98% ee) products from 1-methylenetetralines are readily converted into 3,3-disubstituted oxindoles and subsequently to pyrrolidinoindolines. These hydrovinylation products are also useful for the syntheses of enantiopure benzomorphans.
Mixtures of 2,4- and 2,5-disubstituted zirconacyclopentadienes were obtained by the reductive dimerisation of terminal alkynes using the Cp2ZrCl2/lanthanum system. Reactions of dihalophosphines with these mixtures afforded selectively the corresponding 2,4-disubstituted phospholes and 1,4-disubstituted butadienes. A new series of phospholes was characterized by multi-nuclear NMR spectroscopy an...
Reactions of N,N;-disubstituted hydrazinecarbothioamides 8a-c and substituted thioureidoethylthioureas 9a-c with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil, 10a) and 2,3,5,6-tetrabromo-1,4-benzoquinone (bromanil, 10b) to form N,N;-disubstituted [1,3,4]thiadiazole-2,5-diamines 11a-c, 6,7-dichloro-3-substituted amino-1H-benzo[1,3,4]- thiadiazine-5,8-diones 12a-c, 2,3,7,8-tetrahalothianthrene...
The cyclocondensation of enones with aminoacetonitrile furnishes 3,4-dihydro-2H-pyrrole-2-carbonitriles which can be readily converted to 2,4-disubstituted pyrroles by microwave-induced dehydrocyanation. Alternatively, oxidation of the intermediates produces 3,5-disubstituted pyrrole-2-carbonitriles.
Abstract In this study, 5-substituted and 5,6-disubstituted [4]acenes were synthesized by the double cationic cyclization of fluoroalkenes. (a) After being treated with Me2AlCl (1.2 equiv), 2-trifluoromethyl-1-alkenes bearing two aryl groups underwent domino Friedel–Crafts-type (two-ring construction) followed dehydrogenation to generate 5-fluorinated [4]acenes. The same (trifluoromethyl)alkene...
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