Fundamental Aspects of the Chiral Modification of Platinum with Peptides: Asymmetric Induction in Hydrogenation of Activated Ketones

2009 ◽  
Vol 113 (34) ◽  
pp. 15246-15259 ◽  
Author(s):  
Cecilia Mondelli ◽  
Angelo Vargas ◽  
Gianluca Santarossa ◽  
Alfons Baiker
Keyword(s):  
Asymmetric Induction ◽  
Chiral Modification

P-Chiral 2-{1'-[Butyl(phenyl)phosphanyl]ferrocen-1-yl}-4-isopropyl-4,5-dihydrooxazoles: A Second Chirality Center in Catalytic System

2005 ◽  
Vol 70 (3) ◽  
pp. 361-369 ◽  
Author(s):  
Dušan Drahoňovský ◽  
Petr Štěpnička ◽  
Dalimil Dvořák
Keyword(s):  
Catalytic System ◽  
Asymmetric Induction ◽  
Dimethyl Malonate ◽  
Enantiomerically Pure

P-Chiral (S,RP)-2-{1'-[butyl(phenyl)phosphanyl]ferrocen-1-yl}-4-isopropyl-4,5-dihydrooxazole (6) and (S,SP)-2-{1'-[butyl(phenyl)phosphanyl]ferrocen-1-yl}-4-isopropyl-4,5-dihydrooxazole (7) were prepared by the procedure developed by Jugé, starting from enantiomerically pure (-)- or (+)-ephedrine and dichloro(phenyl)phosphine. Compounds 6 and 7 were examined for asymmetric induction in the Pd-catalyzed reaction of rac-1,3-diphenylallyl acetate with dimethyl malonate. The best results were obtained with 7 (98% ee), while 6 gave 82% ee.

ChemInform Abstract: Remote Asymmetric Induction Using Neighboring Group Participation of a Sulfenyl Group.

ChemInform ◽  
2010 ◽  
Vol 25 (49) ◽  
pp. no-no
Author(s):  
Y. HASHIMOTO ◽  
Y. SATO ◽  
N. TAKESHITA ◽  
K. KUDO ◽  
K. SAIGO
Keyword(s):  
Asymmetric Induction ◽  
Neighboring Group ◽  
Group Participation ◽  
Neighboring Group Participation

ChemInform Abstract: Formal Total Synthesis of Fostriecin via 1,4-Asymmetric Induction Using Cobalt-Alkyne Complex.

ChemInform ◽  
2008 ◽  
Vol 39 (35) ◽  
Author(s):  
Yujiro Hayashi ◽  
Hirofumi Yamaguchi ◽  
Maya Toyoshima ◽  
Kotaro Okada ◽  
Takumi Toyo ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Asymmetric Induction

New chiral tridentate ligands for asymmetric catalysis

2006 ◽  
Vol 78 (2) ◽  
pp. 311-320 ◽  
Author(s):  
Kevin Murtagh ◽  
Brian A. Sweetman ◽  
Patrick J. Guiry
Keyword(s):  
Asymmetric Catalysis ◽  
High Performance ◽  
Aromatic Aldehydes ◽  
Asymmetric Induction ◽  
Tridentate Ligand ◽  
Coupling Reactions ◽  
Tridentate Ligands ◽  
Molecular Complexation ◽  
Cross Coupling Reactions ◽  
Moderate Yield

The synthesis of new tridentate, isoquinoline-derived ligands, involving successive Suzuki cross-coupling reactions, is described. We were able to resolve 1-[3-(2-hydroxy-phenyl)-isoquinolin-1-yl]-naphthalen-2-ol via molecular complexation with N-benzylcinchonidinium chloride, whereas 1,3-bis(2-hydroxy-naphthalen-1-yl)-isoquinoline was resolved by chromatographic separation of its epimeric camphorsulfonates. Their barrier to rotation about the central biaryl axis was evaluated via racemization studies. Application of enantiopure 1,3-bis(2-hydroxynaphthalen-1-yl)-isoquinoline in the addition of diethylzinc to aldehydes proceeded in moderate yield but without asymmetric induction. A new tridentate ligand, 4-tert-butyl-2-chloro-6-[1-(2-hydroxymethyl-naphthalen-1-yl)-isoquinolin-3-yl]-phenol, was prepared in good yield and resolved by semipreparative high-performance liquid chromatography (HPLC). Its application in the addition of diethylzinc to a range of aromatic aldehydes proceeded in near perfect enantioselectivities at low ligand loadings of 1 mol %.

Sign in / Sign up

Export Citation Format

Share Document