Bis-quaternary cinchona alkaloid salts as asymmetric phase transfer catalysts
AssigneeMerck Sharp & Dohme Corp.
InventorsBangping Xiang, Nobuyoshi Yasuda
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Abstract
The invention is directed to novel bis-quarternary cinchona alkaloid salts and the use of bis-quarternary cinchona alkaloid salts in asymmetric phase transfer catalysis. The present invention is directed to novel bis-quarternary cinchona alkaloid salts and the use of bis-quarternary cinchona alkaloid salts in asymmetric phase transfer catalysis. On certain substrates and under specific reaction conditions, the inventors have discovered that the use of bis-quarternary cinchona alkaloid salts in asymmetric phase transfer catalysis surprisingly provides for a more active and efficient process as compared to mono-quarternary catalysts.
Claims6
A bis-quaternary alkaloid salt having the chemical structure of Formula II:
- wherein:
- R1 is ethyl or vinyl;
- R2 is hydrogen or methoxy;
- Ar1 and Ar2 are defined as follows:
- I) Ar1 is:
- and Ar2 is allyl;
- or
- (II) Ar2 is:
- Ar1 is:
- (II) Are is:
- Ar1 is:
- or —CH3;
- and,
- X and Y are independently a halide anion.
A bis-quaternary alkaloid salt having the structure:
- wherein:
- R2 is
- R3 is
- R4 is
- X− is
- Y− is
- OMe
- Br
- Br;
- H
- Br
- Br;
- H
- I
- I;
- H
- Br
- I;
- H
- Br
- Br;
- H
- Me
- Br
- I;
- or
- H
- Allyl
- Br
- Br;
- has the structure.
The bis-quaternary alkaloid salt of the Formula:
Dependencies are inferred from the claim text.