193546-30-4Relevant articles and documents
Synthesis of a novel spiro bisphosphinamidite ligand for highly enantioselective hydrogenation
Lin, Ching Wen,Lin, Chi-Ching,Lam, Louis F.-L.,Au-Yeung, Terry T.-L.,Chan, Albert S.C.
, p. 7379 - 7381 (2007/10/03)
A novel chiral bisphosphinamidite ligand SpiroNP has been synthesized. The rhodium complex of this ligand has been found to be highly active and enantioselective in the asymmetric hydrogenation of (Z)-2-acetamidoacrylic acid derivatives and α,β-unsaturated carboxylic acid derivatives.
A comparison of the asymmetric hydrogenation catalyzed by rhodium complexes containing chiral ligands with a binaphthyl unit and those with a 5,5′,6,6′,7,7′,8,8′-octahydro-binaphthyl unit
Zhang, Fu-Yao,Kwok, Wai Him,Chan, Albert S.C.
, p. 2337 - 2342 (2007/10/03)
The chiral ligands H8-BINAPO and H8-BDPAB were synthesized by reacting chlorodiphenylphosphine with H8-BINOL and H8-BINAM, respectively. Applications of these ligands in the Rh-catalyzed enantioselective hydrogenation of a variety of (Z)-acetamido-3-arylacrylic acid methyl esters provided chiral amino acid derivatives with good to excellent enantioselectivities (H8-BINAPO: up to 84.0% e.e.; H8-BDPAB: up to 97.1% e.e.). In the hydrogenation of acetamidoacrylic acid, 99% e.e. was obtained when a [Rh(H8-BDPAB)]+ catalyst was used. The catalytic activities and enantioselectivities of [Rh(H8-BINAPO)]+ and [Rh(H8-BDPAB]+ are substantially better than those obtained with the corresponding rhodium catalysts containing BINAPO (up to 64% e.e.) and BDPAB (up to 92.6% e.e.).
A highly effective phosphinite ligand derived from D-mannitol for Rh- catalyzed asymmetric hydrogenation
Chen, Yixin,Li, Xingshu,Tong, Siu-Kuen,Choi, Michael C.K.,Chan, Albert S.C.
, p. 957 - 960 (2007/10/03)
A novel chiral phosphinite 1,2,5,6-di-isopropylidene-3, 4- bis(diphenylphosphino)-D-mannitol was prepared and its rhodium complex was found to be an effective catalyst for the asymmetric hydrogenation of amidoacrylic acid and its derivatives with product ee's ranging from 90% to 97%.
Synthesis of chirally pure 2,5-disubstituted diketopiperazines derived from trisubstituted phenylalanines
Danthi, Satyavijayan Narasimhan,Hill, Ronald A.
, p. 835 - 844 (2007/10/03)
Some new chirally pure 2,5-substituted diketopiperazines were synthesized starting from 2-methoxybenzyl alcohol. This multistep synthesis proceeds through the enzymatic synthesis of chirally pure amino acids, protection and dipeptide coupling, cyclization of dipeptide ester formates, and nitration of the resulting diketopiperazines.
