Zobrazeno 1 - 10
of 117
pro vyhledávání: '"Toshiaki Morimoto"'
Publikováno v:
Synthetic Communications. 35:857-865
Racemic trans‐2,3‐di[(3,4‐methylenedioxy)benzyl]‐1,4‐butanediol (dihydrocubebin) 6 was enantioselectively esterified using lipases as catalysts with vinyl acetate. Optically active (S,S)‐1,4‐butanediol 6 obtained was selectively oxygena
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:
Tetrahedron Letters. 41:10025-10029
New P,N ligands prepared from (S)-2-alkyl-2-aminoethylphosphines and α-substituted pyridines are efficient chiral ligands for the copper-catalyzed conjugate addition of diethylzinc to 2-cyclohexen-1-one and chalcone. The best result (90–91% ee) fo
Publikováno v:
Tetrahedron: Asymmetry. 11:4049-4053
Bridging parts X between two amide skeletons of C2-symmetric diphosphine ligands 1 were varied using various kinds of diacyl chlorides. The ligand 1c derived from phthaloyl chloride, which was remarkably effective in the asymmetric induction on palla
Publikováno v:
Tetrahedron: Asymmetry. 10:4501-4511
A new C 2 -symmetric diphosphine ligand 8a was readily prepared in one step by treatment of the synthetic precursor of VALAP, 7 , with phthaloyl chloride. Remarkably high levels of asymmetric induction, over 99% ee, were achieved using 8a in palladiu
Publikováno v:
Tetrahedron: Asymmetry. 10:1025-1028
A novel C2-symmetric chiral diphosphine ligand 1 was developed using (2S)-2-amino-1-(diphenylphosphino)-3-methylbutane 2 which was derived from l -valine as in the previous work for the chiral amidine ligand, VALAP. Ligand 1 demonstrated extremely hi
Publikováno v:
Tetrahedron Letters. 48:3093-3095
New axially chiral P,O,N-type ligands bearing both a diphenylphosphino group and 2-(dialkylamino)ethyloxy (or 2-pyridylmethyloxy) groups were designed and prepared along with P,O,O-type ligands by employing an easily available chiral component, ( R )
Publikováno v:
Tetrahedron: Asymmetry. 9:741-744
Enantioselective allylic substitutions using ketene silyl acetals 3 as a nucleophile have been explored. In the asymmetric reactions of 1,3-diphenylprop-2-enyl pivalate 2 catalyzed by the Pd(0)–chiral amidine 1 complex, excellent levels of stereoco
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
Publikováno v:
Tetrahedron: Asymmetry. 8:3567-3570
Phosphorus-containing amidine 7 was prepared through several steps from L -valine 1 . The new ligand for asymmetric reactions was evaluated in the palladium-catalyzed allylic alkylation of 1,3-diphenylprop-2-enyl acetate and pivalate 8a,b with the nu