# US 5,352,836 A · Enantioselective lewis acid catalysts of the early transition metals

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- Number: US 5,352,836 A
- Document ID: US5352836A
- Status: Granted
- Kind: A
- Application number: 08/047,393
- Filed: 1993-04-19
- Granted: 1994-10-04
- Earliest claimed: 1991-05-01
- Assignees: E. I. Du Pont de Nemours and Company
- Inventors: William A. Nugent, Jr.
- Web page: https://patentgrep.com/patent/US5352836A

## CPC

- C07C 215/12: the nitrogen atom of the amino group being further bound to hydrocarbon groups substituted by hydroxy groups
- B01J 31/2226: {Anionic ligands, i.e. the overall ligand carries at least one formal negative charge}
- B01J 31/2243: {At least one oxygen and one nitrogen atom present as complexing atoms in an at least bidentate or bridging ligand}
- B01J 2231/48: Ring-opening reactions
- B01J 2531/46: Titanium
- B01J 2531/48: Zirconium
- B01J 2531/49: Hafnium
- B01J 2531/56: Vanadium
- B01J 2531/58: Tantalum
- B01J 2531/60: Complexes comprising metals of Group VI (VIA or VIB) as the central metal
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

Optically active Lewis acid catalysts of the early transition metals which are useful in the catalysis of asymmetric additions have been prepared. The catalyst complexes comprise an alkoxide of a group IV or group V metal and an optically active trialkanolamine or dialkanolamine ligand.

## Claims

### Claim 1

An optically active trialkanolamine comprising formula (2) ##STR15## wherein: R.sup.1 is H or CH.sub.3 ;
R.sup.2 and R.sup.3 are each independently C.sub.1 to C.sub.20 hydrocarbyl and may additionally have halogen, ether, or ester groups;
provided that R.sup.1 is CH.sub.3 when R.sup.2 and R.sup.3 are each CH.sub.3.

### Claim 2 (depends on 1)

An optically active trialkanolamine of claim 1, wherein:
R.sup.1 is methyl; and
R.sup.2 and R.sup.3 are each phenyl.

### Claim 3 (depends on 1)

An optically active trialkanolamine of claim 1, wherein:
R.sup.1 is H; and
R.sup.2 and R.sup.3 are each cyclohexyl.

### Claim 4 (depends on 1)

An optically active trialkanolamine of claim 1, wherein:
R.sup.1 is H; and
R.sup.2 and R.sup.3 are each benzyloxymethyl.