133463-91-9Relevant academic research and scientific papers
Cobalt-Catalyzed Enantioselective Negishi Cross-Coupling of Racemic α-Bromo Esters with Arylzincs
Liu, Feipeng,Zhong, Jiangchun,Zhou, Yun,Gao, Zidong,Walsh, Patrick J.,Wang, Xueyang,Ma, Sijie,Hou, Shicong,Liu, Shangzhong,Wang, Minan,Wang, Min,Bian, Qinghua
supporting information, p. 2059 - 2064 (2018/02/14)
The first cobalt-catalyzed enantioselective Negishi cross-coupling reaction, and the first arylation of α-halo esters with arylzinc halides, are disclosed. Employing a cobalt-bisoxazoline catalyst, various α-arylalkanoic esters were synthesized in excellent enantioselectivities and yields (up to 97 % ee and 98 % yield). A diverse range of functional groups, including ether, halide, thioether, silyl, amine, ester, acetal, amide, olefin and heteroaromatics is tolerated by this method. This method was suitable for gram-scale reactions, enabling the synthesis of (R)-xanthorrhizol with high enantiopurity. Radical clock experiments support the intermediacy of radicals.
Bis(oxazoline)titanium complexes as chiral catalysts for enantioselective hydrosilylation of ketones - A combined experimental and theoretical investigation
Bandini, Marco,Bernardi, Fernando,Bottoni, Andrea,Cozzi, Pier Giorgio,Miscione, Gian Pietro,Umani-Ronchi, Achille
, p. 2972 - 2984 (2007/10/03)
A combined experimental and theoretical investigation has been carried out on a new catalytic system, based on bis-(oxazoline) (BOX) complexes of titanium. These catalytic species are able to reduce aromatic ketones with good enantiomeric excesses and satisfactory yields. The experimental and the computational (DFT) evidence has provided useful information on the nature of the active catalytic species and on the mechanism of the reaction. The most likely reaction path involves a TiIV catalytic species. This result agrees with experimentally obtained evidence that seems to rule out the presence of TiIII species. The analysis of the structure of the transition state corresponding to the reduction process (the addition of the hydride to the carbonyl system), provides an interesting insight on the enantioselectivity that characterizes this reaction. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
C2-Symmetric 4,4',5,5'-Tetrahydrobi(oxazoles) and 4,4',5,5'-Tetrahydro-2,2'-methylenebis as Chiral Ligands for Enantioselective Catalysis
Mueller, Dieter,Umbricht, Gisela,Weber, Beat,Pfaltz, Andreas
, p. 232 - 240 (2007/10/02)
The synthesis of a series of enantiomerically pure, C2-symmetric 4,4',5,5'-tetrahydro-2,2'-methylene-bis and 4,4',5,5'-tetrahydro-2,2'-bi(oxazoles) is reported.Copper complexes with anionic tetrahydromethylenebis ligands are efficient c
