Zobrazeno 1 - 10
of 68
pro vyhledávání: '"Kazuo Achiwa"'
Publikováno v:
Chemical and Pharmaceutical Bulletin. 52:1445-1450
Axially chiral biphenyldiphosphine ligands bearing diphenylphosphino group(s) and/or dicyclohexylphosphino group(s) were prepared in enantiomerically pure form starting from 2,6-dimethylnitrobenzene via 8 steps: iodination, reduction, methoxylation t
Publikováno v:
Chemical and Pharmaceutical Bulletin. 47:436-439
Novel chiral bisphosphine ligands bearing (2S, 5S)-dimethylphospholano group on a chiral biphenyl back-bone were designed and prepared. Asymmetric hydrogenations of a ketone and an olefin with the rhodium(I) complex catalysts prepared in situ from [R
Publikováno v:
Tetrahedron: Asymmetry. 9:183-187
An optically active 1-hydroxymethyl-substituted tetrahydroisoquinoline alkaloid, ( S )-calycotomine 1 , was conveniently synthesized by using catalytic asymmetric hydrogenation of 1-benzyloxymethyl-3,4-dihydro-6,7-dimethoxyisoquinoline 6 with 0.5 mol
Autor:
Kazuo Achiwa, Toshiaki Morimoto
Publikováno v:
Tetrahedron: Asymmetry. 6:2661-2664
The asymmetric hydrogenation of cyclic ketimines, 1-alkyl-3,4-dihydroisoquinolines 5a,b , was carried out with diphosphine-iridium(I) complex catalysts in the presence of various imides or amides as a co-catalyst. Remarkable effects of five-membered
Autor:
Kazuo Achiwa, Shunji Sakuraba
Publikováno v:
Chemical and Pharmaceutical Bulletin. 43:748-753
N-(Methylcarbamoyl)-4-(dicyclohexylphosphino)-2-[(diphenylphosphino)methyl]pyrrolidine (MCCPM)- and N-(tert-butoxycarbonyl)-4-(dicyclohexylphosphino)-2-[(diphenylphosphino)methyl]pyrrolidine (BCPM)-rhodium(I) complexes were efficient catalysts for as
Publikováno v:
Chemical and Pharmaceutical Bulletin. 43:738-747
The complexes of pyrrolidine bisphosphine ligands (CPMs) with rhodium (I) were found to be efficient catalysts for asymmetric hydrogenation of α-amino ketone hydrochloride derivatives. Utilizing this methodology, we have developed efficient asymmetr
Publikováno v:
Tetrahedron: Asymmetry. 6:23-26
Remarkable effects of the substituted diphenylphosphino groups of modified DIOPs on the enantioselectivity were observed in the asymmetric hydrogenation of α-phenyl-substituted enamides using their rhodium(I) complexes as catalysts. MOD-DIOP bearing
Publikováno v:
Tetrahedron: Asymmetry. 6:75-78
A new chiral bisphosphine ligand (6) bearing a cyclobutane framework was readily prepared by using diastereoselective [2+2] cycloaddition. Its rhodium(I) complex was found to be an efficient catalyst for the asymmetric hydrogenation of a cyclic enami
Publikováno v:
Chemical and Pharmaceutical Bulletin. 42:481-488
Chiral pyrrolidinebisphosphine ligands, (2S-cis)-BCPM and (2S-cis)-BCPP, bearing two different types of phosphino groups, a dicyclohexylphosphino group and a diphenylphosphino groups, were designed and prepared on the basis of our design concept for
Publikováno v:
Tetrahedron. 49:1793-1806
Optically pure (R)-arylmethylsuccinic acid mono-methyl esters were obtained efficiently by using the catalytic asymmetric hydrogenation of arylidenesuccinic acid monoesters with a rhodium(I) complex of a chiral bisphosphine, (4S,5S)-MOD-DIOP. Asymmet