3618-99-3Relevant academic research and scientific papers
Electron-donating and rigid p-stereogenic bisphospholane ligands for highly enantioselective rhodium-catalyzed asymmetric hydrogenations
Zhang, Xiaowei,Huang, Kexuan,Hou, Guohua,Cao, Bonan,Zhang, Xumu
supporting information; experimental part, p. 6421 - 6424 (2010/12/19)
More electron donating, more rigid: A new highly electron-donating P-stereogenic bisphospholane ligand (ZhangPhos) was synthesized in a practical and highly enantioselective manner from a commercially available chiral source. Better or comparable enantioselectivities and reactivities than TangPhos were achieved in rhodium-catalyzed hydrogenation of various functionalized olefins (see scheme; nbd=3,5-norbornadiene). Copyright
Design and synthesis of a novel three-hindered quadrant bisphosphine ligand and its application in asymmetric hydrogenation
Huang, Kexuan,Zhang, Xiaowei,Emge, Thomas J.,Hou, Guohua,Cao, Bonan,Zhang, Xumu
supporting information; experimental part, p. 8555 - 8557 (2011/01/03)
A novel three hindered quadrant bisphosphine ligand has been synthesized. The ligand shows excellent enantioselectivities and reactivities for rhodium-catalyzed hydrogenations of various functionalized olefins.
One-pot tandem enantioselective hydrogenation-hydroformylation synthesis of cyclic α-amino acids
Teoh, Euneace,Campi, Eva M.,Jackson, W. Roy,Robinson, Andrea J.
, p. 387 - 394 (2007/10/03)
Five- and six-membered cyclic amino acids can be prepared in good yield with high ee (> 95%) via tandem rhodium-DuPHOS catalysed asymmetric hydrogenation followed by a rhodium-catalysed hydroformylation-cyclisation sequence in a single pot. The synthesis can be achieved using Rh-DuPHOS as the sole catalyst.
A highly enantioselective synthesis of cyclic α-amino acids involving a one-pot, single catalyst, tandem hydrogenation-hydroformylation sequence
Teoh, Euneace,Campi, Eva M.,Roy Jackson,Robinson, Andrea J.
, p. 978 - 979 (2007/10/03)
Tandem enantioselective hydrogenation followed by a hydroformylation-cyclisation sequence leading to cyclic α-amino acids with ee's > 95% can be achieved in a single pot, one catalyst system by successive reactions of prochiral dienamide esters with H2 followed by H2/CO using Rh(I)DuPHOS.
Catalytic Asymmetric Hydrogenation of Methyl (E)- and (Z)-2-Acetamido-3-alkylacrylates
Scott, John W.,Keith, Dennis D.,Nix, George,Parrish, David R.,Remington, Stuart,et al.
, p. 5086 - 5093 (2007/10/02)
Rhodium-chiral phosphine complex catalyzed homogeneous hydrogenations of methyl (Z)- and (E)-2-acetamido-4-methoxybut-2-enoates ((Z,E)-10), methyl (Z)- and (E)-2-acetamidohex-2-enoates ((Z,E)-16A) and methyl (Z)- and (E)-2-acetamido-4-methylpent-2-enoates ((Z,E)-16B) are reported.With phosphines in which two achiral phosphorus atoms are connected by a chiral four-carbon unit, higher product enantiomeric excesses (ee's) are obtained from E than from Z substrates.With phosphines in which a two-carbon chiral unit separates two achiral phosphorus atoms, Z substrates are preferred.With dipamp (28), both Z and E substrates (particularly (Z,E)-16A) are reduced with high enantioselectivity.The additional oxygen atom in substrates (Z,E)-10 has little effect on product ee with most phosphines.
