594815-59-5Relevant academic research and scientific papers
Variation of xanthene-based bidentate ligands in the palladium-catalyzed arylation of ureas
Sergeev, Alexey G.,Artamkina, Galina A.,Beletskaya, Irina P.
, p. 4719 - 4723 (2003)
A series of xanthene-based bidentate ligands containing various substituents on diphenylphosphino groups were synthesized and tested in the palladium-catalyzed arylation reaction of urea with unactivated aryl bromides. It was found that both steric and electronic properties of the ligands have a pronounced effect on the yields and ratios of the products. Arylation of urea and phenylurea with unactivated aryl bromides in the presence of Pd2dba3·CHCl3/3,5-(CF3) 2Xantphos and Cs2CO3 as base in dioxane at 100°C gave the corresponding N,N′-diarylureas in 62-98% yields.
Palladium-catalyzed three-component diaryl sulfone synthesis exploiting the sulfur dioxide surrogate DABSO
Emmett, Edward J.,Hayter, Barry R.,Willis, Michael C.
supporting information, p. 12679 - 12683 (2013/12/04)
SO(2) efficient: A three-component palladium-catalyzed coupling of aryl lithium compounds; sulfur dioxide (provided by the easy-to-handle solid surrogate, DABSO); and aryl, heteroaryl, and alkenyl (pseudo)halides yields a diverse library of sulfones. An electron-poor XantPhos-type ligand suppresses aryl-aryl exchange and is key to obtaining high yields.
Copper-catalyzed highly regio- and stereoselective directed hydroboration of unsymmetrical internal alkynes: Controlling regioselectivity by choice of catalytic species
Semba, Kazuhiko,Fujihara, Tetsuaki,Terao, Jun,Tsuji, Yasushi
supporting information; experimental part, p. 4179 - 4184 (2012/05/31)
A highly selective synthesis of the αand β products by copper-catalyzed hydroboration utilizing two different catalytic copper species generated from pinacolborane (HBpin) and B2pin2 is reported. Regioselectivity in the crude reaction mixtures is found to be high, and the corresponding a products were isolated in good yields. In the case of an alkyne containing an alkenyl moiety, the regioselectivity decreased to 72:28. In hydroboration reactions catalyzed by other transition metals, selecting between hydrometalation and boryl metalation is difficult because the oxidative addition of HB to a metal center provides an H-M-B species, containing both H-M and B-M bonds. The α and β products are valuable intermediates used in the Suzuki-Miyaura cross-coupling reaction to regioselectively prepare various trisubstituted alkenes of types 5α and 5β.
Copper-catalyzed highly selective semihydrogenation of non-polar carbon-carbon multiple bonds using a silane and an alcohol
Semba, Kazuhiko,Fujihara, Tetsuaki,Xu, Tinghua,Terao, Jun,Tsuji, Yasushi
supporting information; experimental part, p. 1542 - 1550 (2012/08/08)
A copper catalyst bearing a suitable Xantphos derivative or NHC ligand was found to be highly efficient for the selective semihydrogenation of non-polar unsaturated compounds using a mixture of a silane and an alcohol as reducing agent. The catalytic system was useful for the selective semihydrogenation of internal alkynes to (Z)-alkenes with suppression of overreduction to the corresponding alkanes. Furthermore, semihydrogenations of terminal alkyne, 1,2-diene, 1,3-diene, 1,3-enyne and 1,3-diyne systems were also achieved selectively. Copyright
Variation of xantphos-based ligands in the palladium-catalyzed reaction of aryl halides with ureas
Sergeev,Artamkina,Beletskaya
, p. 1741 - 1752 (2007/10/03)
A series of Xantphos-based ligands containing various substituents in the diphenylphosphino groups were synthesized, and their effect on the product yield and ratio in the palladium-catalyzed arylation of ureas with nonactivated aryl halides was studied. The arylation of urea and phenylurea in the presence of Pd2(dba)3-CHCl3, 3,5-(CF3) 2Xantphos, and Cs2CO3 in dioxane at 100°C gave the corresponding N,N′-diarylureas in 62-98% yield.
