Synthesis of new chiral catalysts, pyridyl- and bipyridylalcohols, for the enantioselective addition of diethylzinc to benzaldehyde

Chiral 2,2‘-Bipyridines, 1,10-Phenanthrolines, and 2,2‘:6‘,2‘ ‘-Terpyridines: Syntheses and Applications in Asymmetric Homogeneous Catalysis

“…26 All the studied ligands induced formation of the R-enantiomer of 1-phenyl-1-propanol with good enantiomeric excess. The chirality at the stereocenter involving the C′-hydroxy group was not a criterion for high enantioselectivity.…”

“…10 The synthesis of the 3-sec-butylbpy (26) is based on the cyclization of the monoprotected 1,5-dicarbonyl compound 25, which was prepared by following two different pathways starting from the chiral alcohol 1. 10 In one approach, the aldehyde 24 was transformed into 25 by treatment with 2-pyridyllithium followed by oxidation of the intermediate crude carbinol with activated MnO 2 (60% overall yield).…”

Novel Chiral Di-2-pyridyl Ketone Ligands: Crystal Structure of a Copper Complex and its Activity in the Copper-Catalyzed Enantioselective Cyclopropanation of Styrene

“…, 1997Ϫ2002 1998 dipyridyl ketone and copper is much larger than that observed for the chiral bipyridine complex (83°). [ (7) 117.2(8) O(2)ϪC(8)ϪC (9) 118.5(8) C(7)ϪC(8)ϪC (9) 124.3 (7) The use of copper complexes prepared from CuOTf and bipyridines as catalysts in the cyclopropanation of alkenes have been reported by Katsuki et al and our group. [9] To investigate if these dipyridyl ketone ligands had similar reactivity, we studied the cyclopropanation with complex 7 (Scheme 3).…”

Chiral Aryl Pyridyl Alcohols as Enantioselective Catalysts in the Addition of Diethylzinc to Substituted Benzaldehydes

“…This substitution yields ligands 6-10. 45,46 This characteristic affects the steric interactions between the ligand and the substrate, both coordinated to the metal, and, therefore, the stereoselectivity.…”