ChemInform Abstract: Efficient Asymmetric Addition of Diethylzinc to Aldehydes Using C₂‐Novel Chiral Pyridine β‐Amino Alcohols as Chiral Ligands.

Abstract

Chiral Pyridine -Amino Alcohols as Chiral Ligands. -(ZHANG, W.; TANG*, R.; YU, H.; GAO, S.; Appl. Organomet. Chem. 28 (2014) 7, 545-551, http://dx.

EnantioselectiveEthylation of Various Aldehydes Catalyzed by Readily Accessible Chiral Diols

“…Since the pioneering study of Oguni and Omi, the design and development of selective and efficient ligand structures have been significantly investigated for this useful transformation. Several nitrogen‐ and oxygen‐functionalized chiral ligand structures, including amino alcohols, diols, and diamines, have been designed through different synthetic routes. Their catalytic activities have been investigated via the addition of diethylzinc to prochiral aldehydes to yield enantioenriched secondary alcohols.…”

Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by Chiral O,N,O‐tridentate Phenol Ligands Derived From Camphor

“…Tridentate ligands should confer more rigidity to the reactive zinc chelate catalyst structures, thereby allowing better discrimination between the two enantiotopic faces of an aldehyde in the transition state complex. Recently, some tridentate and polydentate chiral ligands have been synthesized and applied to the enantioselective addition of diethylzinc to aldehydes . In this line, Hayashi et al have developed O,N,O‐ligands based on Schiff bases derived from tert ‐leucinol and salicylaldehyde, which were effective for the asymmetric addition of diethylzinc to aldehydes (up to 96% enantiomeric excess [ ee ] for benzaldehyde).…”