Conversion of alcohols to alkyl esters and carboxylic acids using heterogeneous palladium-based catalysts

Patent metadata

Field	Value
Publication number	US-9593064-B2
Application number	US-201514702266-A
Country	US
Kind code	B2
Filing date	May 1, 2015
Priority date	May 1, 2014
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

Disclosed are methods for synthesizing an ester or a carboxylic acid from an organic alcohol. To form the ester one reacts, in the presence of oxygen gas, the alcohol with methanol or ethanol. This reaction occurs in the presence of a catalyst comprising palladium and a co-catalyst comprising bismuth, tellurium, lead, cerium, titanium, zinc and/or niobium (most preferably at least bismuth and tellurium). Alternatively that catalyst can be used to generate an acid from that alcohol, when water is also added to the reaction mix.

First claim

We claim:

1. A method for synthesizing an ester from two alcohols, comprising:
reacting, in the presence of oxygen gas, an alkyl alcohol R 2 —OH wherein R 2 is an alkyl moiety having less than three carbons with a compound of the formula R 1 CH 2 OH;
wherein said reacting is in the presence of a catalyst comprising palladium and at least one co-catalyst comprising bismuth and tellurium;
wherein an ester of the following formula is formed:
R 1 —CO—O—R 2 ;

wherein R 1 is an alkyl, cyclic, aryl, heterocyclic, arene, amine, ether, or ester, with or without sulfur or halogen content;
wherein R 2 is an alkyl moiety having less than three carbons; and wherein
(a) R 1 is alkyl; or
(b) the catalyst comprises at least 0.1 mol percent palladium, at least 0.01 mol percent bismuth, and at least 0.01 mol percent tellurium; or
(c) the catalyst comprises bismuth in a salt form and tellurium in a metal form; or
(d) within the catalyst, bismuth and tellurium have been deposited onto palladium using wet impregnation; or
(e) the catalyst further comprises lead.

2. The method of claim 1 , wherein R 2 is CH 3 .

3. The method of claim 2 , wherein R 1 is alkyl.

4. The method of claim 2 wherein methanol is reacted with a primary alcohol selected from the group consisting of aliphatic alcohols and benzylic alcohols.

5. The method of claim 2 , wherein the catalyst further comprises an elemental carbon support.

6. The method of claim 5 , wherein the elemental carbon support is in the form of charcoal or activated carbon.

7. The method of claim 5 , wherein the catalyst comprises at least 0.1 mol percent palladium, at least 0.01 mol percent bismuth, and at least 0.01 mol percent tellurium.

8. The method of claim 2 , in which the bismuth is present in a salt form and the tellurium is present in a metal form.

9. The method of claim 8 , wherein the bismuth salt is Bi(NO 3 ) 3 .5H 2 O.

10. The method of claim 2 , in which the reacting takes place at least 40° C.

11. The method of claim 2 , in which bismuth and tellurium have been deposited onto palladium using wet impregnation.

12. The method of claim 2 , in which the catalyst further comprises lead.

13. A method for synthesizing an ester from two alcohols, comprising:
reacting, in the presence of oxygen gas, an alkyl alcohol having less than three carbons with a compound of the formula R 1 CH 2 OH;
wherein said reacting is in the presence of a catalyst comprising palladium and a co-catalyst comprising at least two of the following: bismuth, tellurium, lead, cerium, titanium, zinc and niobium;
wherein an ester of the following formula is formed:
R 1 —CO—O—R 2 ;

wherein R 1 is an alkyl, cyclic, aryl, heterocyclic, arene, amine, ether, or ester, with or without sulfur or halogen content; and
wherein R 2 is an alkyl moiety having less than three carbons.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Stahl Shannon S
• Powell Adam B
• Root Thatcher W
• Mannel David S
• Ahmed Maaz S

Classifications

• B01J23/6484

  Niobium · CPC title

• C07C65/21

  containing ether groups, [IMAGE cpc-sch-C07C-0958.gif] groups,[IMAGE cpc-sch-C07C-0959.gif] groups, or[IMAGE cpc-sch-C07C-0960.gif] groups · CPC title

• B01J23/58

  with alkali- or alkaline earth metals · CPC title

• C07C51/235 Primary

  of —CHO groups or primary alcohol groups · CPC title

• C07C67/40

  by oxidation of primary alcohols · CPC title