Evaluation of Catalyst Acidity and Substrate Electronic Effects in a Hydrogen Bond-Catalyzed Enantioselective Reaction
作者:Katrina H. Jensen、Matthew S. Sigman
DOI:10.1021/jo1013806
日期:2010.11.5
A modular catalyst structure was applied to evaluate the effects of catalystacidity in a hydrogen bond-catalyzed hetero Diels−Alder reaction. Linear free energy relationships between catalystacidity and both rate and enantioselectivity were observed, where greater catalystacidity leads to increased activity and enantioselectivity. A relationship between reactant electronic nature and rate was also
Assembled Dendritic Titanium Catalysts for Enantioselective Hetero-Diels–Alder Reaction of Aldehydes with Danishefsky's Diene
作者:Baoming Ji、Yu Yuan、Kuiling Ding、Jiben Meng
DOI:10.1002/chem.200305286
日期:2003.12.15
titanium-catalyzed hetero-Diels-Alderreaction of Danishefsky's diene with aldehydes. These reactions afforded the corresponding 2-substituted 2,3-dihydro-4H-pyran-4-ones in quantitative yields and with excellent enantioselectivities (up to 97.2 % ee). The disposition of the dendritic wedges and the dendron size in the ligands were found to have significant impact on the enantioselectivity of the reaction. The recovered
Asymmetric Hetero Diels-Alder Reaction Catalyzed by Chiral Ytterbium(III) Phosphate{Yb[(<i>R</i>)-(-)-BNP]<sub>3</sub>}: Remarkable Ligand Effect on the Enantioselectivity
作者:T. Hanamoto、H. Furuno、Y. Sugimoto、J. Inanaga
DOI:10.1055/s-1997-718
日期:——
2,6-Lutidine was found to be an effective additive for the chiral ytterbium(III) phosphate Yb[(R)-(-)-BNP]3}-catalyzed asymmetric hetero Diels-Alder reaction thus achieving high enantioselectivity (up to 93% ee) at room temperature.
Methods of performing cycloadditions, reaction mixtures, and methods of performing asymmetric catalytic reactions
申请人:The University of Chicago
公开号:US07230125B1
公开(公告)日:2007-06-12
Methods of performing cycloadditions are described that include (a) combining a first reactant and a second reactant in a hydrogen bonding solvent to form a reaction mixture; and (b) reacting the first reactant and the second reactant to form a cycloadduct. Methods of performing asymmetric catalytic reactions are also described that include (a) combining a first reactant, a second reactant, and a catalytic amount of a chiral hydrogen-bond donor in a solvent to form a reaction mixture; and (b) reacting the first reactant and the second reactant to form an enantiomeric excess of a reaction product. Reaction mixtures corresponding to these methods are also described.
Design of Hydrogen Bond Catalysts Based on a Modular Oxazoline Template: Application to an Enantioselective Hetero Diels−Alder Reaction
作者:Sridhar Rajaram、Matthew S. Sigman
DOI:10.1021/ol052300x
日期:2005.11.1
[reaction: see text] A catalyst system that displays two hydrogenbond donating arms from a rigid oxazoline backbone and its utility in a hydrogenbond promoted enantioselective hetero Diels-Alderreaction are described.