Back to results
US 6,919,456 B2Granted
Catalytic compositions and methods for asymmetric aldol reactions
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsBarry M. Trost, Hisanaka Ito
Life of this patent
Estimating the term…
Abstract
Methods and compositions are provided for the direct catalytic asymmetric aldol reaction of aldehydes with donor molecules selected from ketones and nitroalkyl compounds. The reactions employ as catalyst a Group 2A or Group 2B metal complex of a ligand of formula I, as defined further herein.
Claims8
A chiral ligand of formula I:
- where
- R1-R4 are aryl groups, which may be the same or different, each of which is unsubstituted or substituted with one or more substituents X, where each X is independently selected from alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl, aralkynyl, alkoxy, aryloxy, amide, alkyl- or aryl sulfonyl, sulfonamide, hydroxy, cyano, nitro, and halogen,
- wherein R1 and R2, or R3 and R4, or both of these combinations, may be linked at an α-carbon of each said group to form a tricyclic or larger ring system;
- m is an integer from 0 to 3;
- each of R5 and R6 represents one or more substituents independently selected from the group consisting of hydrogen and X as defined above;
- and
- R7 represents one or more substituents on the phenol ring independently selected from the group consisting of hydrogen, X as defined above, and a further fused ring.
4 more elements
Dependencies are inferred from the claim text.