Diastereoselective alkoxymethylation of aromatic aldehydes with chiral lithiomethyl ethers. Synthesis of optically active monoprotected glycols

1998 ◽  
Vol 76 (10) ◽  
pp. 1338-1343 ◽  
Author(s):  
Viviana L Ponzo ◽  
Teodoro S Kaufman
Keyword(s):  
Key Words ◽  
Aromatic Aldehydes ◽  
Optically Active ◽  
Asymmetric Induction ◽  
Diastereoselective Synthesis ◽  
Benzyl Alcohols

The synthesis of optically active α-alkoxymethyl benzyl alcohols by reaction of polysubstituted benzaldehydes with chiral α-alkoxymethyllithiums, easily obtained by transmetallation of the corresponding α-alkoxystannanes with n-butyllithium, is reported. Chemical yields of the transformation are good while low asymmetric induction (<1.6:1) is obtained. Key words: diastereoselective synthesis, monoprotected glycols, chiral alkoxymethyllithiums, addition to aldehydes, optically active alcohols.

Diastereoselective Synthesis of Novel Optically Active Five Membered O- and N-heterocyclic Compounds

2012 ◽  
Vol 9 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Ervin Kovacs ◽  
Ferenc Farkas ◽  
Angelika Thurner ◽  
Aron Szollosy ◽  
Ferenc Faigl
Keyword(s):  
Heterocyclic Compounds ◽  
Optically Active ◽  
Diastereoselective Synthesis

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 %.

ChemInform Abstract: CATALYTIC ASYMMETRIC INDUCTION IN OXIDATION REACTIONS. THE SYNTHESIS OF OPTICALLY ACTIVE EPOXIDES

1976 ◽  
Vol 7 (35) ◽  
pp. no-no
Author(s):  
R. HELDER ◽  
J. C. HUMMELEN ◽  
R. W. P. M. LAANE ◽  
J. S. WIERING ◽  
H. WYNBERG
Keyword(s):  
Optically Active ◽  
Asymmetric Induction ◽  
Oxidation Reactions ◽  
Catalytic Asymmetric

A synthetic strategy for tricholomic acid and acivicin

1987 ◽  
Vol 65 (1) ◽  
pp. 195-199 ◽  
Author(s):  
Stephen Hanessian ◽  
Benoit Vanasse
Keyword(s):  
Malic Acid ◽  
Aldol Condensation ◽  
Optically Active ◽  
Asymmetric Induction ◽  
Bond Forming ◽  
Synthetic Strategy

A synthetic strategy towards tricholomic acid and acivicin has been established using the aldol condensation of N-pyruvilideneglycinatoaquocopper(II) and an optically active aldehyde derived from S-malic acid as the key bond-forming reaction. Although a viable strategy was developed, no asymmetric induction was observed.

Synthesis of optically active ‘Dewar’ benzenes; asymmetric induction

1975 ◽  
pp. 972-972 ◽  
Author(s):  
Jan H. Dopper ◽  
Ben Greijdanus ◽  
Dré Oudman ◽  
Hans Wynberg
Keyword(s):  
Optically Active ◽  
Asymmetric Induction
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