64330-66-1Relevant academic research and scientific papers
Convenient synthesis of 2,5-disubstituted thiophene from 1,6-dioxo-2,4- diene
Ong, Chi Wi,Chen, Chong Ming,Wang, Long Fu,Shieh, Po Chuen
, p. 9191 - 9192 (1998)
Reaction of 1,6-dioxo-2,4-diene with P2S5 and Lawesson's reagent affords the 2,5-disubstituted thiophene. This reaction can take place regioselectively in the presence of BF3-etherate catalysis, useful for the synthesis of
N-Vinylpyridinium tetrafluoroborate salts as reagents for the stereoselective and regioselective synthesis of symmetrical (2E,4E)-1,6-dioxo-2,4-dienes
Gao, Ge,Brown, Neil,Minatoya, Machiko,Buszek, Keith R.
scheme or table, p. 6491 - 6494 (2009/04/06)
We had previously demonstrated the utility of N-vinylpyridinium tetrafluoroborate salts as novel electrophilic coupling partners in Pd(0)-catalyzed Suzuki cross-coupling reactions with aryl and vinyl boronic acids. We now report that these crystalline, air-stable, and non-hygroscopic salts are also useful reagents for the synthesis of symmetrical (2E,4E)-1,6-dioxo-2,4-dienes (diene diones), which in turn are valuable starting materials for the synthesis of various five-membered heterocycles. The optimization of reaction conditions and the scope and limitations of the reductive dimerization are discussed.
N-vinylpyridinium and -ammonium tetrafluoroborate salts: New electrophilic coupling partners for Pd(0)-catalyzed suzuki cross-coupling reactions
Buszek, Keith R.,Brown, Neil
, p. 707 - 710 (2007/10/03)
N-Vinylpyridinium and -trialkylammonium tetrafluoroborate salts represent a new class of electrophilic coupling partner for Pd(0)-catalyzed Suzuki cross-coupling reactions and give very good to excellent yields of products with a wide range of boronic acids. The salts are easily prepared from activated acetylenes and pyridinium or trialkylammonium tetrafluoroborates to form crystalline, air-stable, and nonhygroscopic crystals.
Thermal Rearrangements, XXII. The Propargyl-Cope Rearrangement of meso- and d,l-3,4-Dimethyl-1,5-hexadiyne-3,4-diol
Hopf, Henning,Hamann, Uwe,Zimmermann, Gerhard,Remmler, Matthias
, p. 959 - 964 (2007/10/02)
The thermal behavior of meso- and d,l-3,4-dimethyl-1,5-hexadiyne-3,4-diol (meso- and d,l-4) has been studied at 400 deg C in the gas phase.In a tandem reaction the diols isomerize via the bisallenes 5 first to cis- and trans-3,4-diacetylcyclobutene (cis- and trans-8) which have been detected as intermediates by 13C-NMR spectroscopy as well as catalytic hydrogenation to 1,2-diacetylcyclobutane (9).Subsequently, 8 stabilizes itself by ring opening to (E,Z)- and (E,E)-3,5-octadien-2,7-dione .As a side reaction retro-ene cleavage of 4 to 2-butynone (10) and methyl vinyl ketone (12) is observed.By pyrolysis of the pure diastereomers 4 it is shown that the retro-ene process is more pronounced in the d,l than in the meso series. - Key Words: Rearrangements, thermal / Propargyl-Cope reaction / 1,5-Hexadiyne-3,4-diol / Cyclobutene, 3,4-diacetyl- / Fragmentations, retro-ene / Tandem reactions
"Head-to-head" dimerization and dehydrodimerization of vinyl ketones catalyzed by modified rhodium(I) complexes
Kovalev, I. P.,Kolmogorov, Yu. N.,Strelenko, Yu. A.,Ignatenko, A. V.,Vinogradov, M. G.,Nikishin, G. I.
, p. 125 - 133 (2007/10/02)
The dimerization of vinyl ketones RC(O)CH=CH2, I (R = Me, tBu, Ph, p-MeC6H4, cyclopropyl, 2-(5-methylfuryl)) at 80 deg C in the presence of the catalytic system 2-MCl2 leads preferably to either α,β-unsaturated 1,6-diketones RC(O)C
