# US 2017/0283447 A1 · Ruthenium complexes and their uses as catalysts in processes for formation and/or hydrogenation of esters, amides and related reactions

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- Number: US 2017/0283447 A1
- Document ID: US20170283447A1
- Status: Published application
- Kind: A1
- Application number: 15/508,114
- Filed: 2015-09-03
- Published: 2017-10-05
- Earliest claimed: 2014-09-04
- Assignees: Yeda Research and Development Co. Ltd.
- Applicants: Yeda Research and Development Co. Ltd.
- Inventors: David MILSTEIN; Peng HU; Eran FOGLER; Jai Anand Garg Narayana RAO
- Web page: https://patentgrep.com/patent/US20170283447A1

## CPC

- C07F 15/0046: {Ruthenium compounds}
- B01J 31/24: Phosphines {, i.e. phosphorus bonded to only carbon atoms, or to both carbon and hydrogen atoms, including e.g. sp2-hybridised phosphorus compounds such as phosphabenzene, phosphole or anionic phospholide ligands}
- B01J 31/2404: {Cyclic ligands, including e.g. non-condensed polycyclic ligands, the phosphine-P atom being a ring member or a substituent on the ring}
- B01J 31/28: of the platinum group metals, iron group metals or copper
- C07C 29/149: with hydrogen or hydrogen-containing gases
- C07C 67/00: Preparation of carboxylic acid esters
- C07C 67/40: by oxidation of primary alcohols
- C07C 209/00: Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C 209/50: by reduction of carboxylic acid amides
- C07C 213/00: Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
- C07C 227/02: Formation of carboxyl groups in compounds containing amino groups, e.g. by oxidation of amino alcohols
- C07C 231/02: from carboxylic acids or from esters, anhydrides, or halides thereof by reaction with ammonia or amines
- C07C 231/08: from amides by reaction at nitrogen atoms of carboxamide groups
- C07C 231/10: from compounds not provided for in groups C07C231/02 - C07C231/08
- C07C 249/02: of compounds containing imino groups
- C07D 207/16: Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals
- C07D 241/08: with oxygen atoms directly attached to ring carbon atoms
- B01J 2231/641: Hydrogenation of organic substrates, i.e. H2 or H-transfer hydrogenations, e.g. Fischer-Tropsch processes
- B01J 2231/763: of -CH-XH (X= O, NH/N, S) to -C=X or -CX triple bond species
- B01J 2531/0244: Pincer-type complexes, i.e. consisting of a tridentate skeleton bound to a metal, e.g. by one to three metal-carbon sigma-bonds
- B01J 2531/821: Ruthenium
- C07C 2601/14: The ring being saturated
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

The present invention relates to novel Ruthenium complexes of formulae A1-A4 and their use, inter alia, for (1) dehydrogenative coupling of alcohols to esters; (2) hydrogenation of esters to alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di-lactones), or polyesters); (3) preparing amides from alcohols and amines—(including the preparation of polyamides (e.g., polypeptides) by reacting dialcohols and diamines and/or polymerization of amino alcohols and/or forming cyclic dipeptides from p-aminoalcohols; (4) hydrogenation of amides (including cyclic dipeptides, polypeptides and polyamides) to alcohols and amines; (5) hydrogenation of organic carbonates (including polycarbonates) to alcohols or hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (6) dehydrogenation of secondary alcohols to ketones; (7) amidation of esters (i.e., synthesis of amides from esters and amines); (8) acylation of alcohols using esters; (9) coupling of alcohols with water and a base to form carboxylic acids; and (10) preparation of amino acids or their salts by coupling of amino alcohols with water and a base. The present, invention further relates to the use of certain known Ruthenium complexes for the preparation of amino acids or their salts from amino alcohols.

## Claims

### Claim 1

A Ruthenium complex represented by the structure of any of formulae A1, A2, A3 or A4:
wherein
L1 is selected from the group consisting of phosphine (PRbRc), phosphite P(ORb)(ORc), phosphinite P(ORb)(Rc), amine (NRbRc), imine, oxazoline, sulfide (SRb), sulfoxide (S(═O)Rb), heteroaryl containing at least one heteroatom selected from nitrogen and sulfur; arsine (AsRbRc), stibine (SbRbRc) and a N-heterocyclic carbene represented by the structures:
L2 is a mono-dentate two-electron donor selected from the group consisting of CO, PRbRcRd, P(ORb)(ORc)(ORd), NO+, AsRbRcRd, SbRbRcRd, SRbRc, nitrile (RCN), isonitrile (RNC), N2, PF3, CS, heteroaryl, tetrahydrothiophene, alkene and alkyne;
L3 is absent or is L2;
Y and Z are each independently H or an anionic ligand selected from the group consisting of H, halogen, OCOR, OCOCF3, OSO2R, OSO2CF3, CN, OR, N(R)2 and RS;
Ra is H, alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl or alkylheteroaryl;
Rb, Rc and Rd are each independently alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl or alkylheteroaryl;
R, R1, R2 and R3 are each independently H, alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl or alkylheteroaryl;
X represents zero, one, two or three substituents independently selected from the group consisting of alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl, alkylheteroaryl, halogen, nitro, amide, ester, cyano, alkoxy, alkylamino, arylamino, an inorganic support and a polymeric moiety;
anion ⊖ represents a group bearing a single negative charge; and
cation ⊕ represents a group bearing a single positive charge.

### Claim 2 (depends on 1)

The complex of claim 1, wherein X represents zero substituents; L1 is phosphine (PRbRc); L2 is CO; and Z and Y are independently H or halogen.

### Claim at position 3

3-6. (canceled)

### Claim 7 (depends on 1)

The complex of claim 1, wherein Z of structure A1 is H, and the complex is represented by the structure A1′:

### Claim 8 (depends on 1)

The complex of claim 1, which is represented by the structure of formula B1:

### Claim 9 (depends on 8)

The complex of claim 8, wherein L2 is CO; Ra is selected from the group consisting of H, alkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; and Rb and Rc are each independently selected from the group consisting of alkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim at position 7

10-11. (canceled)

### Claim 12 (depends on 8)

The complex of claim 8, which is represented by the structure of formula 4:

### Claim 13

(canceled)

### Claim 14 (depends on 1)

The complex of claim 1, wherein the structure of formula A2 is represented by the structure of formula B2:

### Claim 15 (depends on 14)

The complex of claim 14, which is represented by the structure of formula 1, 2 or 3:

### Claim 16

(canceled)

### Claim 17 (depends on 1)

A process for preparing an ester by dehydrogenative coupling of alcohols, comprising the step of reacting an alcohol or a combination of alcohols in the presence of a Ruthenium complex as a catalyst, thereby generating the ester and molecular hydrogen; or a process of hydrogenating an ester, comprising the step of reacting the ester with molecular hydrogen (H2) in the presence a Ruthenium complex as a catalyst, thereby hydrogenating the ester; wherein the Ruthenium complex is a Ruthenium complex according to claim 1.

### Claim 18 (depends on 17)

The process of claim 17, which is selected from the group consisting of:
(i) a process comprising the step of converting a primary alcohol represented by formula R4CH2OH to an ester by the structure R4—C(═O)—OCH2R4:
wherein R4 is selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, haloalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl;
(ii) a process comprising the step of reacting a first primary alcohol represented by formula R4CH2OH with a second primary alcohol represented by formula R4′CH2OH so as to generate an ester by the structure R4—C(═O)—OCH2R4′ or an ester of formula R4′—C(═O)—OCH2R4
wherein R4 and R4′ are each independently selected is from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, haloalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; and
(iii) a process comprising the step of reacting a primary alcohol represented by formula R4CH2OH with a secondary alcohol of formula R4′R4″CHOH so as to generate an ester by the structure R4—C(═O)—OCHR4′R4″:
wherein R4, R4′ and R4″ are each independently selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, haloalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 19 (depends on 17)

The process of claim 17, wherein the alcohol is selected from the group consisting of methanol, ethanol, n-propanol, iso-propanol, n-butanol, isobutanol, t-butanol, n-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methoxyethanol, 2,2,2-trifluoroethanol, 2-methyl-1-butanol, 3-methyl-1-butanol, benzyl alcohol, 2-methoxy benzyl alcohol, 3-methoxy benzyl alcohol, 4-methoxy benzyl alcohol, 1-phenylethanol, and cyclohexane methanol; or
wherein the alcohol is a dialcohol, and the process results in a polyester or a lactone.

### Claim 20

(canceled)

### Claim 21 (depends on 17)

The process of claim 17, comprising the step of hydrogenating an ester represented by the formula R5C(═O)—OR6 to the corresponding alcohol or alcohols:
wherein
R5 is selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; and
R6 is selected from the group consisting of an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 22 (depends on 17)

The process of claim 17, wherein R5 is H and the process comprises hydrogenating a formate ester of formula H—C(═O)—OR6 to methanol and an alcohol of formula R6—OH.

### Claim 23 (depends on 17)

The process of claim 17, wherein the ester is selected from the group consisting of hexyl hexanoate, methyl hexanoate, cyclohexyl hexanoate, tert-butyl acetate, cyclohexyl acetate, 2,2,2-trifluoroethyl 2,2,2-trifluoroacetate, benzyl benzoate, ethyl 3-phenylpropanoate, ethyl benzoate, butyl butyrate, methyl formate, ethyl formate, propyl formate butyl formate, methyl trifluoroacetate, methyl difluoroacetate and methyl monofluoroacetate; or
wherein the ester is a cyclic ester (lactone), or
wherein the ester is a cyclic di-ester (di-lactone), and the process results in the formation of a diol; preferably wherein the cyclic ester is oxepan-2-one and the diol formed is hexane 1,6-diol; or wherein the cyclic di-ester is biomass-derived, preferably wherein the cyclic di-ester is glycolide or lactide; or
wherein the ester is a polyester.

### Claim 24 (depends on 1)

A process for preparing an amide, comprising the step of reacting a primary or secondary amine with a primary alcohol in the presence of the Ruthenium complex according to as a catalyst, thereby generating the amide and molecular hydrogen; or a process for hydrogenating an amide to an alcohol and an amine, comprising the step of reacting the amide with molecular hydrogen (H2) in the presence of the Ruthenium complex as a catalyst, thereby generating the amine and alcohol; wherein the Ruthenium complex is a Ruthenium complex according to claim 1.

### Claim 25 (depends on 24)

The process of claim 24, comprising the step of reacting an amine represented by formula R7R7′NH with an alcohol represented by the formula R8CH2OH to generate an amide represented by the structure R8—C(═O)—NR7R7′:
wherein R7, R7′ and R8 are each independently selected from the group consisting of H an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; or R7 and R7′ are joined to form a ring together with the nitrogen.

### Claim 26 (depends on 24)

The process of claim 24, wherein (a) the amine is a diamine or the alcohol is a dialcohol, and the process results in a diamide; or (b) the amine is a diamine and the alcohol is a dialcohol, and the process results in a polyamide; or (c) the amine and alcohol are present in the same molecule, and the process is an intra-molecular process which results in a lactam; or (d) the amine and the alcohol are present in the same molecule, and the process is an inter-molecular process which results in a polyamide; or (e) the amine and alcohol together represent a beta-amino alcohol, and the process results in a polypeptide; or (f) the amine and alcohol together represent a beta-amino alcohol, and the process is an intra-molecular process which results in a cyclic dipeptide.

### Claim 27 (depends on 26)

The process of claim 26, wherein said amide is prepared by reacting ethylenediamine (ED) with ethanol in the presence of said Ruthenium catalyst, to generate N,N′-diacetylethylenediamine (DAE)

### Claim 28 (depends on 24)

The process of claim 24, wherein the amine and alcohol together represent a beta-amino alcohol, and the process is an inter-molecular process which results in a polypeptide, an intra-molecular process which results in a cyclic dipeptide, or a combination thereof.
wherein R is H or alkyl;
R9 is selected from the group consisting of H an unsubstituted or substituted alkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; and
n is 1 to 20; preferably
wherein R9 is H or methyl, and the process is conducted in the presence of a solvent; or
wherein the beta-amino alcohol is ethanolamine or 2-(methylamino) ethanol, and the process results in glycine anhydride (GA) or N,N-dimethyl GA:
wherein the process optionally results in a mixture of (i) glycine anhydride or N,N-dimethyl GA; and (ii) a linear peptide represented by the structure:
wherein R is H or CH3, and n is an integer of 1 to 20.

### Claim 29

(canceled)

### Claim 30 (depends on 24)

The process of claim 24, comprising the step of hydrogenating an amide represented by the formula R10C(═O)—N—R11R11′ to an alcohol of formula R10CH2OH and amine of formula R11R11′NH:
wherein R10, R11 and R11′ are each independently selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 31 (depends on 24)

The process of claim 24, wherein said amide is N,N-diacetylethylenediamine (DAE), and said N,N′-diacetylethylenediamine (DAE) is hydrogenated to generate ethylenediamine (ED) and ethanol

### Claim 32 (depends on 24)

The process of claim 24 wherein the amide is selected from the group consisting of N-benzyl-2-methoxyacetamide, N-hexyl-2-methoxyacetamide, N-hexyl-3-methyloxetane-3-carboxamide, N-hexyl-2-furanylcarboxamide, N-benzylbenzamide, N-ethylacetamide, N-methylpropionamide, N-cyclohexyl-2-methoxyacetamide, N-phenylacetamide, N-phenylhexylamide, 2-methoxy-N-phenylacetamide, N-phenylbenzamide, Ethylenediamine-N,N′-(2-methoxyacetamide), N-hexanoylmorpholine, N-butanoylmorpholine, N-2-metoxyacetylpyrrolidine, N-formylmorpholine, N,N-dimethylformamide, N,N-diethylbenzamide, benzamide, 4-methylbenzamide, cyclohexanecarboxamide, hexanamide, acetamide, acrylamide and pivalamide; or
the amide is a cyclic amide (lactam) and the process results in an amino alcohol, preferably wherein the cyclic amide is glycine anhydride (GA) or N,N-dimethyl GA and the process results in ethanolamine or 2-(methylamino) ethanol:
wherein R is H or CH3; or
the amide is a polyamide, or the amide is a polypeptide.

### Claim 33 (depends on 1)

A process for hydrogenating an organic carbonate, carbamate or urea derivative, comprising the step of reacting the organic carbonate, carbamate or urea derivative with molecular hydrogen (H2) in the presence of the Ruthenium complex according to claim 1 as a catalyst, thereby hydrogenating the organic carbonate, carbamate or urea derivative and generating at least one alcohol, amine or combination thereof.

### Claim 34 (depends on 33)

The process of claim 33, which is selected from the group consisting of:
(i) a process comprising the step of hydrogenating a carbonate represented by the formula R12O—C(═O)—OR12′ to the corresponding alcohols(s) and methanol:
wherein R12 and R12′ are the same or different and are selected from the group consisting of an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl;
(ii) a process comprising the step of hydrogenating a carbamate represented by the formula R13O—C(═O)—NHR14 to the corresponding amine, alcohol and methanol:
wherein R13 is selected from the group consisting of an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; and
R14 is selected from the group consisting of H or an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl; and
(iii) a process comprising the step of hydrogenating a urea derivative to the corresponding amine and methanol:
wherein each of R15a and R16a, which may be the same or different, is selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, and heterocyclyl, and each of R15b and R16b, which may be the same or different, is selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, and heterocyclyl; or wherein at least one of R15a and R15b, and/or R16a and R16b together with the nitrogen to which they are attached form a heterocyclic ring.

### Claim 35 (depends on 34)

The process of claim 34 wherein the carbonate is a polycarbonate, or wherein the carbamate is a polycarbamate or wherein the urea derivative is a polyurea derivative.

### Claim 36 (depends on 1)

A process for preparing a ketone by dehydrogenation of a secondary alcohol, comprising the step of reacting the secondary alcohol in the presence of the Ruthenium complex according to claim 1 as a catalyst, thereby generating the ketone and molecular hydrogen.

### Claim 37 (depends on 36)

The process of claim 36, comprising the step of converting a secondary alcohol represented by formula R17CH(OH)R17′ to a ketone represented by the structure R17—C(═O)—R17′:
wherein R17 and R17′ are each independently selected from the group consisting of H or an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 38 (depends on 1)

A process for preparing an amide, comprising the step of reacting a primary or secondary amine with an ester in the presence of the Ruthenium complex according to claim 1 as a catalyst, thereby generating the amide and molecular hydrogen.

### Claim 39 (depends on 38)

The process of claim 38, comprising the step of reacting an amine represented by formula R18R18′NH with an ester represented by the formula R19—C(═O)—OCH2R19′ to generate an amide represented by the structure R19—C(═O)—NR18R18′ or R19′—C(═O)—NR18R18′:
wherein R18, R18′, R19 and R19′ are each independently selected from the group consisting of H an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 40 (depends on 1)

A process for preparing an ester by reacting a primary or secondary alcohol with an ester in the presence of the Ruthenium complex according to claim 1 as a catalyst, thereby generating the ester and molecular hydrogen.

### Claim 41 (depends on 40)

The process of claim 40, comprising the step of reacting a primary or secondary alcohol represented by formula R21R21′CHOH with an ester by the structure R20—C(═O)—OCH2R20′:
wherein R20, R20′, R21 and R21′ are each independently selected from the group consisting of H, an unsubstituted or substituted alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 42 (depends on 1)

A process for preparing a carboxylic acid comprising the step of reacting a primary alcohol with water and a base in the presence of the Ruthenium complex according to claim 1 as a catalyst, thereby generating the carboxylic acid and molecular hydrogen.

### Claim 43 (depends on 42)

The process of claim 42, comprising the step of reacting a primary alcohol represented by formula R22CH2OH with water in the presence of a base so as to generate a carboxylic acid salt represented by the structure R22—C(═O)O− and, optionally, if desired, converting the carboxylic acid salt to the corresponding carboxylic acid of formula R22—C(═O)OH
wherein R22 is selected from the group consisting of H, an unsubstituted or substituted alkyl, aminoalkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl.

### Claim 44 (depends on 1)

A process for preparing an amino acid or a salt thereof, by contacting an amino alcohol with the Ruthenium complex according to claim 1 as a catalyst, in the presence of water and a base, under conditions sufficient to generate the amino acid or a salt thereof.

### Claim 45 (depends on 44)

The process of claim 44, wherein the amino alcohol is a β- or γ-amino alcohol and the reaction is represented by the scheme:
wherein R23 is H or an unsubstituted or substituted alkyl; and
n is 1 or 2.

### Claim 46 (depends on 44)

The process of claim 44, wherein the amino alcohol is selected from the group consisting of 2-aminoethanol (ethanolamine), 2-amino-1-butanol, diethanolamine, 2-aminopropanol, N-methylethanolamine, N,N-dimethylethanolamine, N-isopropylethanolamine, t-tert-butylethanolamine, 2-amino-3-methyl-1-butanol, prolinol, 2-amino-3-phenyl-1-propanol, 2-amino-2-phenyl-1-ethanol, 3-aminopropanol, N,N-dimethyl-3-aminopropanol, 3-amino-3-phenyl-1-propanol, and 2-aminobenzyl alcohol, or salts of any of the foregoing.

### Claim 47 (depends on 44)

The process of claim 44, wherein the resultant amino acid is selected from the group consisting of glycine, α-aminobutyric acid, 2-(2-hydroxyethylamino)acetic acid, alanine, sarcosine, dimethylglycine, N-isopropyl glycine, N-tert-butyl glycine, leucine, proline, phenylalanine, 2-phenylglycine, β-alanine, N,N-dimethyl-β-alanine, 3-amino-3-phenyl propanoic acid, and anthranilic acid, or salts of any of the foregoing.

### Claim at position 44

48-53. (canceled)

### Claim 54 (depends on 1)

A process selected from the group consisting of:
(i) a process for preparing a Ruthenium complex represented by the structure of formula A1 of claim 1, the process comprising the step of reacting a Ruthenium complex of formula A2 of claim 1, in the presence of at least two equivalents of a base:
wherein L1, L2, X, Y, Z and Ra are as defined in claim 1;
the process preferably comprising the step of preparing a Ruthenium complex represented by the structure of formula 4 from a precursor of formula 1
(ii) a process for preparing a Ruthenium complex represented by the structure of formula A4 of claim 1, the process comprising the step of reacting a Ruthenium complex of formula A3 of claim 1, in the presence of at least two equivalents of a base:
wherein L1, L2, L2, Y, Z and Ra are as defined in claim 1; and
(iii) a process for preparing a Ruthenium complex represented by the structure of formula A2 of claim 1, the process comprising the steps of reacting a precursor of formula B with a Ruthenium reagent represented by the structure Ru(Z)(Y)(L2)(P(Ar)3)
wherein Ar is phenyl or an alkyl-substituted phenyl;
the process preferably comprising the step of reacting a precursor of formula B′ with Ru(H)Cl(CO)(PPh3) to generate a compound of formula 1, 2 or 3:
wherein Ra is t-butyl (compound 1), isopropyl (compound 2) or benzyl (compound 3).

### Claim 55

(canceled)

### Claim 56

(canceled)

### Claim 57

A process for preparing an amino acid or a salt thereof by contacting an amino alcohol with a Ruthenium complex as a catalyst, in the presence of water and a base, under conditions sufficient to generate the amino acid or a salt thereof, wherein the Ruthenium complex is selected from the group consisting of:
(i) a complex of Formula A11′, A22′ or A33′:
wherein
L1 and L2 are each independently selected from the group consisting of nucleophilic carbene (:C(R)2), P(R)2, P(OR)2, N(R)2, imine, SR, SH, S(═O)R, heteroaryl wherein the heteroatom is selected from nitrogen and sulfur, As(R)2, Sb(R)2 and an N-heretocyclic carbene represented by the structure:
each of R, R2 and R3 are independently selected from the group consisting of alkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl;
L3 is a mono-dentate two-electron donor selected from the group consisting of CO, P(R)3, P(OR)3, NO+, As(R)3, Sb(R)3, S(R)2, nitrile (RCN) and isonitrile (RNC) wherein R is as defined above;
L4 is absent or is L3;
Y and Z are each independently H or an anionic ligand selected from the group consisting of halogen, OCOR, OCOCF3, OSO2R, OSO2CF3, CN, OH, OR, N(R)2, RS and SH; wherein R is as defined above;
X represents zero, one, two or three substituents selected from the group consisting of alkyl, aryl, halogen, nitro, amide, ester, cyano, alkoxy, cycloalkyl, alkylaryl, heterocyclyl, heteroaryl, an inorganic support and a polymeric moiety; anion represents a group bearing a single negative charge; and
(ii) A complex of Formula A1″, A2″ and A3″:
wherein
L1 is selected from the group consisting of phosphine (PRaRb), phosphite P(ORa)(ORb), phosphinite P(ORa)(Rb), amine (NRaRb), imine, oxazoline, sulfide (SRa), sulfoxide (S(═O)Ra), heteroaryl containing at least one heteroatom selected from nitrogen and sulfur; arsine (AsRaRb), stibine (SbRaRb) and a N-heterocyclic carbene represented by the structures:
L2 is a mono-dentate two-electron donor selected from the group consisting of CO, PRaRbRc, P(ORa)(ORb)(ORc), NO+, AsRaRbRc, SbRaRbRc, SRaRb, nitrile (RCN), isonitrile (RNC), N2, PF3, CS, heteroaryl, tetrahydrothiophene, alkene and alkyne;
L3 is absent or is L2;
Y and Z are each independently H or an anionic ligand selected from the group consisting of H, halogen, OCOR, OCOCF3, OSO2R, OSO2CF3, CN, OR, N(R)2 and RS;
Ra, Rb and Rc are each independently alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl or alkylheteroaryl;
R, R1, R2 and R3 are each independently H, alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl or alkylheteroaryl;
X1 represents zero, one, two or three substituents and X2 represents zero, one, two, three or four substituents, wherein each such substituent is independently selected from the group consisting of alkyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkylcycloalkyl, alkylaryl, alkylheterocyclyl, alkylheteroaryl, halogen, nitro, amide, ester, cyano, alkoxy, alkylamino, arylamino, an inorganic support and a polymeric moiety; and
anion represents a group bearing a single negative charge.

### Claim 58 (depends on 57)

The process of claim 57, wherein the amino alcohol is a β- or γ-amino alcohol and the reaction is represented by the scheme:
wherein R23 is H or an unsubstituted or substituted alkyl; and
n is 1 or 2.

### Claim 59 (depends on 57)

The process of claim 57, wherein the amino alcohol is selected from the group consisting of 2-aminoethanol (ethanolamine), 2-amino-1-butanol, diethanolamine, 2-aminopropanol, N-methylethanolamine, N,N-dimethylethanolamine, N-isopropylethanolamine, t-tert-butylethanolamine, 2-amino-3-methyl-1-butanol, prolinol, 2-amino-3-phenyl-1-propanol, 2-amino-2-phenyl-1-ethanol, 3-aminopropanol, N,N-dimethyl-3-aminopropanol, 3-amino-3-phenyl-1-propanol, and 2-aminobenzyl alcohol, or salts of any of the foregoing.

### Claim 60 (depends on 57)

The process of claim 57 wherein the resultant amino acid is selected from the group consisting of glycine, α-aminobutyric acid, 2-(2-hydroxyethylamino)acetic acid, alanine, sarcosine, dimethylglycine, N-isopropyl glycine, N-tert-butyl glycine, leucine, proline, phenylalanine, 2-phenylglycine, β-alanine, N,N-dimethyl-β-alanine, 3-amino-3-phenyl propanoic acid, and anthranilic acid, or salts of any of the foregoing.

### Claim 61 (depends on 57)

The process of claim 57, wherein the Ruthenium complex is represented by any one of the structures of formulas (i)-(vi):

### Claim at position 53

62-66. (canceled)