# US 5,705,678 A · Oxotitanium complex, asymmetric hydrogenation catalyst comprising the complex, and process for producing .beta.-hydroxy ketone or .alpha.-hydroxy carboxylic acid ester using the complex

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- Number: US 5,705,678 A
- Document ID: US5705678A
- Status: Granted
- Kind: A
- Application number: 08/775,192
- Filed: 1996-12-30
- Granted: 1998-01-06
- Earliest claimed: 1994-03-11
- Assignees: Takasago International Corporation
- Inventors: Takeshi Nakai; Dai Kitamoto; Noboru Sayo
- Web page: https://patentgrep.com/patent/US5705678A

## CPC

- B01J 31/223: {At least two oxygen atoms present in one at least bidentate or bridging ligand}
- B01J 31/2226: {Anionic ligands, i.e. the overall ligand carries at least one formal negative charge}
- C07C 45/511: {involving transformation of singly bound oxygen functional groups to >C = O groups (involving two hydroxy groups C07C45/52; hydroperoxides C07C45/53)}
- C07C 45/72: by reaction of compounds containing >C = O groups with the same or other compounds containing >C = O groups
- C07C 67/343: by increase in the number of carbon atoms
- C07C 67/347: by addition to unsaturated carbon-to-carbon bonds
- C07F 7/003: {without C-Metal linkages}
- B01J 2231/341: 1,2-additions, e.g. aldol or Knoevenagel condensations
- B01J 2531/0266: Axially chiral or atropisomeric ligands, e.g. bulky biaryls such as donor-substituted binaphthalenes, e.g. "BINAP" or "BINOL"
- B01J 2531/46: Titanium
- B01J 2540/34: Sulfonyl groups
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)

## Abstract

A novel oxotitanium complex represented by general formula (I) is disclosed: ##STR1## wherein R.sup.1 and R.sup.2 may be the same or different and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a phenyl group, a substituted phenyl group, a trialkylsilyl group, a monoalkyldiphenylsilyl group, a dialkylmonophenylsilyl group, a triphenylsilyl group, a substituted triphenylsilyl group, or a lower alkoxycarbonyl group, provided that R.sup.1 and R.sup.2 may be bonded to each other to form a hydrocarbon ring or a substituted hydrocarbon ring in cooperation with the carbon atoms to which R.sup.1 and R.sup.2 are bonded; R.sup.3 and R.sup.4 may be the same or different and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a benzoyl group, a benzenesulfonyl group, or a halogen atom, provided that R.sup.3 and R.sup.4 may be bonded to each other to form a hydrocarbon ring or a substituted hydrocarbon ring in cooperation with the carbon atoms to which R.sup.3 and R.sup.4 are bonded; and n is 1 or 2. The novel oxotitanium complex is useful as an asymmetric reaction catalyst. A process for producing a .beta.-hydroxy ketone or an .alpha.-hydroxy carboxylic acid ester in the presence of the novel oxotitanium complex is also disclosed.

## Claims

### Claim 1

A process for producing an .alpha.-hydroxy carboxylic acid ester represented by general formula (V): ##STR16## wherein R.sup.6 represents a hydrogen atom or a lower alkyl group and R.sup.7 represents a lower alkyl group, a phenyl group, or a cycloalkyl group, provided that R.sup.6 and R.sup.7 may be bonded to each other to form a hydrocarbon ring in cooperation with the carbon atoms to which R.sup.6 and R.sup.7 are bonded, and R.sup.8 represents a lower alkyl group, or
for producing a .beta.-hydroxy ketone represented by general formula (VIII): ##STR17## wherein R.sup.9 and R.sup.10 may be the same or different and each represents a hydrogen atom or a lower alkyl group, R.sup.11 represents a lower alkyl group, a lower alkoxy group, a phenyl group, a phenoxy group, or a lower alkylthio group, and R.sup.15 represents a lower alkyl group, a lower alkoxymethyl group, a phenyl group, a substituted phenyl group, a benzyloxymethyl group, or a lower alkoxycarbonyl group, which process comprises
(A) reacting an olefin compound represented by general formula (III): ##STR18## wherein R.sup.6 and R.sup.7 have the same meanings as defined above, with a glyoxylate compound represented by general formula (IV): ##STR19## wherein R.sup.8 has the same meaning as defined above, in the presence of an oxotitanium complex to thereby produce the .alpha.-hydroxy carboxylic acid ester, or
(B) reacting a silyl enol ether compound represented by general formula (VI): ##STR20## wherein R.sup.9, R.sup.10, and R.sup.11 have the same meanings as defined above, and R.sup.12, R.sup.13, and R.sup.14 may be the same or different and each represents a lower alkyl group or a phenyl group, with an aldehyde compound represented by general formula (VII):
R.sup.15 CHO (VII)
wherein R.sup.15 has the same meaning as defined above, in the presence of an oxotitanium complex to thereby produce the .beta.-hydroxy ketone,
wherein said oxotitanium complex is represented by general formula (I): ##STR21## wherein R.sup.1 and R.sup.2 may be the same or different and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a phenyl group, a substituted phenyl group, a trialkylsilyl group, a monoalkyldiphenylsilyl group, a dialkylmonophenylsilyl group, a triphenylsilyl group, a substituted triphenylsilyl group, or a lower alkoxycarbonyl group, provided that R.sup.1 and R.sup.2 may be bonded to each other to form a hydrocarbon ring or a substituted hydrocarbon ring in cooperation with the carbon atoms to which R.sup.1 and R.sup.2 are bonded; R.sup.3 and R.sup.4 may be the same or different and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a benzoyl group, a benzenesulfonyl group, or a halogen atom, provided that R.sup.3 and R.sup.4 may be bonded to each other to form a hydrocarbon ring or a substituted hydrocarbon ring in cooperation with the carbon atoms to which R.sup.3 and R.sup.4 are bonded; and n is 1 or 2.