A series of Mn(I) catalysts containing imidazole-based chiral PNN tridentateligands with controllable ‘side arm’ groups have been established, enabling the inexpensive base-promoted asymmetric hydrogenation of simple ketones with outstanding activities (up to 8200 TON) and good enantioselectivities (up to 88.5% ee). This protocol features wide substrate scope and functional group tolerance, thereby
Highly Enantioselective Addition of Dialkylzincs to Aromatic Aldehydes Using 1-Phenyl-2-(1-pyrrolidinyl)-1-propanol as a Chiral Catalyst
作者:Kenso Soai、Takashi Konishi、Takanori Shibata
DOI:10.3987/com-99-8532
日期:——
(1S,2R)- and (1R,2S)-1-phenyl-2-(1-pyrrolidinyl)-1-propanol catalyzes the enantioselective addition of dialkylzincs to aromatic aldehydes to afford enantiomerically enriched aromatic sec-alcohols with up to 92% enantiomeric excess.
Facile synthesis of chiral isopropyl carbinols with high enantiomeric excess via catalytic enantioselective addition of diisopropylzinc to aldehydes
作者:Weon Ki Yang、Byung Tae Cho
DOI:10.1016/s0957-4166(00)00253-6
日期:2000.7
Highly effective syntheses of chiral alkyl and aryl isopropyl carbinols with highenantiomericexcess (94–98% ee) via catalytic enantioselective addition of diisopropylzinc to aldehydes have been developed.
Linear β-amino alcohol catalyst anchored on functionalized magnetite nanoparticles for enantioselective addition of dialkylzinc to aromatic aldehydes
作者:Carla Sappino、Ludovica Primitivo、Martina De Angelis、Francesco Righi、Federica Di Pietro、Marika Iannoni、Luciano Pilloni、Stefano Vecchio Ciprioti、Lorenza Suber、Alessandra Ricelli、Giuliana Righi
DOI:10.1039/d0ra04554c
日期:——
A linear β-amino alcohol ligand, previously found to be a very efficientcatalyst for enantioselective addition of dialkylzinc to aromatic aldehydes, has been anchored on differently functionalized superparamagnetic core–shell magnetite–silica nanoparticles (1a and 1b). Its catalytic activity in the addition of dialkylzinc to aldehydes has been evaluated, leading to promising results, especially in
Application of well-defined chain-end-functionalized polystyrenes with dendritic chiral ephedrine moieties as reagents for highly catalytic enantioselective addition of dialkylzincs to aldehydes
作者:Ashraf A. El-Shehawy、Kenji Sugiyama、Akira Hirao
DOI:10.1016/j.tetasy.2007.12.020
日期:2008.3
having a definite number of chiral ephedrine moieties dendritically distributed at the periphery of their hyperbranched chain-ends were evaluated as chiral catalysts for the enantioselectiveaddition of dialkylzinc reagents to aldehydes. These dendritic macromolecules worked well as homogeneous chiral catalysts and exhibited high catalytic activity and enantioselectivity very similar to those observed