Hydroxylation of β-dicarbonyls with zirconium catalysts
AssigneeE. I. Du Pont de Nemours and Company
InventorAlbert Loren Casalnuovo
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Abstract
The present invention pertains to a process for preparing a compound of Formula I that is achiral, racemic or enantiomerically enriched at the hydroxylation center indicated by * comprising contacting a compound of Formula II with an oxidant selected from oxygen, hydrogen peroxide, peracids or alkyl hydroperoxides in the presence of a zirconium complex, wherein R1, R2 and R3 are as defined in the disclosure. This invention also pertains to zirconium complexes useful in this procedure comprising zirconium and a ligand of Formula III or its enantiomer wherein J, R6 and n are as defined in the disclosure. This invention further pertains to a compound of Formula III or its enantiomer.
Claims8
A chiral compound of Formula III of at least about 50% enantiomeric purity
- wherein
- J is
- each R6 is independently selected from the group consisting of halogen;
- NO2;
- cyano;
- C2-C5 alkoxycarbonyl;
- N(C1-C4 alkyl)2;
- CON(C1-C4 alkyl)2;
- C1-C4 alkoxy;
- C2-C5 alkylcarbonyloxy;
- C2-C5 alkoxycarbonyloxy;
- optionally substituted phenylcarbonyloxy;
- tri(C1-C4 alkyl)silyl;
- tri(C1-C4 alkyl)siloxy;
- C1-C4 alkyl optionally substituted with 1-3 phenyl rings;
- C3-C6 cycloalkyl optionally substituted with C1-C2 alkyl;
- adamantyl;
- a phenyl ring, or a 5- or 6-membered heteroaromatic ring, each ring optionally substituted;
- and
- when two R6 are attached to adjacent phenyl ring carbon atoms, said two R6 may be taken together with the phenyl ring to form a naphthalene ring system optionally substituted on either ring of said naphthalene ring system;
- each R8 is independently selected from C1-C4 alkyl, C1-C4 alkoxy, halogen and nitro;
- each n is independently an integer from 0 to 4;
- and
- each q is independently an integer from 0 to 3.
A chiral compound of Formula ent-III of at least about 50% enantiomeric purity
- wherein
- J is
- each R6 is independently selected from the group consisting of halogen;
- NO2;
- cyano;
- C2-C5 alkoxycarbonyl;
- N(C1-C4 alkyl)2;
- CON(C1-C4 alkyl)2;
- C1-C4 alkoxy;
- C2-C5 alkylcarbonyloxy;
- C2-C5 alkoxycarbonyloxy;
- optionally substituted phenylcarbonyloxy;
- tri(C1-C4 alkyl)silyl;
- tri(C1-C4 alkyl)siloxy;
- C1-C4 alkyl optionally substituted with 1-3 phenyl rings;
- C3-C6 cycloalkyl optionally substituted with C1-C2 alkyl;
- adamantyl;
- a phenyl ring, or a 5- or 6-membered heteroaromatic ring, each ring optionally substituted;
- and
- when two R6 are attached to adjacent phenyl ring carbon atoms, said two R6 may be taken together with the phenyl ring to form a naphthalene ring system optionally substituted on either ring of said naphthalene ring system;
- each R8 is independently selected from C1-C4 alkyl, C1-C4 alkoxy, halogen and nitro;
- each n is independently an integer from 0 to 4;
- and
- each q is independently an integer from 0 to 3.
Dependencies are inferred from the claim text.