Oxidation of alkanes to alcohols

Patent metadata

Field	Value
Publication number	US-2016002139-A1
Application number	US-201414770039-A
Country	US
Kind code	A1
Filing date	Feb 25, 2014
Priority date	Feb 25, 2013
Publication date	Jan 7, 2016
Grant date	—

Abstract

The invention provides processes and materials for the efficient and cost-effective functionalization of alkanes, such as methane from natural gas, to provide esters, alcohols, and other compounds. The method can be used to produce liquid fuels such as methanol from a natural gas methane-containing feedstock. The soft oxidizing electrophile, a compound of a main group, post-transitional element such as Tl, Pb, Bi, and I, that reacts to activate the alkane C—H bond can be regenerated using inexpensive regenerants such as hydrogen peroxide, oxygen, halogens, nitric acid, etc. Main group compounds useful for carrying out this reaction includes haloacetate salts of metals having a pair of available oxidation states, such as Tl, Pb, Bi, and I. The inventors herein believe that a unifying feature of many of the MXn electrophiles useful in carrying out this reaction, such as Tl, Pb, and Bi species, is their isoelectronic configuration in the alkane-reactive oxidation state; the electrons having the configuration [Xe]4f145d10, with an empty 6s orbital. However, the iodine reagents have a different electronic configuration.

First claim

1 . A process for oxidizing an alkane to an alkane oxygenate, comprising
contacting the alkane and (i) a soft oxidizing electrophile comprising a main group element in oxidized form, or (ii) an oxidant and a reduced form of the soft oxidizing electrophile, in an acidic medium comprising an oxygen acid, to provide the alkane oxygenate and an electrophile reduction product; and optionally separating the alkane oxygenate and the electrophile reduction product.

2 . The process of claim 1 , further comprising contacting the electrophile reduction product and an oxidizing regeneration reagent to regenerate the soft oxidizing electrophile.

3 . The process of claim 1 , wherein the soft oxidizing electrophile comprises the element thallium, lead, antimony, selenium, tellurium, or bismuth, each in oxidized form.

4 . (canceled)

5 . The process of claim 1 , wherein the soft oxidizing electrophile comprises one or more trifluoroacetate, acetate, sulfate, or alkylsulfonate anions.

6 . (canceled)

7 . The process of claim 1 , wherein the alkane is methane, ethane, or propane, or any mixture thereof.

8 . The process of claim 1 , wherein the soft oxidizing electrophile comprising a main group element in oxidized form is a salt wherein the counterion of the main group element in oxidized form is a conjugate anion of an acid of the acidic medium.

9 . The process of claim 8 , wherein the acidic medium comprises trifluoroacetic acid, acetic acid, or methanesulfonic acid, and the counterion of main group element in oxidized form is trifluoroacetate, acetate, or methanesulfonate, respectively.

10 . (canceled)

11 . (canceled)

12 . The process of claim 1 , wherein the soft oxidizing electrophile of formula M +n X n , wherein M is a metal or non-metal main group element cation in an oxidation state of n, X is an anionic counterion, and n is the number of anionic charges necessary to balance the n+ positive charge of the metal ion.

13 . (canceled)

14 . (canceled)

15 . The process of claim 12 , wherein M +n X n undergoes reaction with the alkane in the acidic medium to yield an electrophile reduction product of formula M +(n-2) X n-2 or M +(n-1) X n-1 .

16 . The process of claim 2 , wherein the oxidizing regeneration reagent is molecular oxygen, hydrogen peroxide, chlorine, nitric acid, or ozone.

17 . The process of claim 2 , wherein the electrophile reduction product and the oxidizing regeneration reagent are contacted to regenerate the soft oxidizing electrophile in the presence of an oxidative regeneration catalyst.

18 . The process of claim 17 , wherein the oxidative regeneration catalyst comprises copper, silver, iron, or vanadium.

19 . The process of claim 1 , wherein the medium further comprises an aprotic medium, comprising an anhydrous, poorly nucleophilic, polar liquid.

20 . The process of claim 19 , wherein the aprotic medium is liquid sulfur dioxide, trifluoroethanol, tetrachloroethane, or dichloromethane, or a mixture thereof.

21 . The process of claim 2 , wherein the oxidizing regeneration reagent is present in at least stoichiometric quantities relative to the alkane, in the acidic medium with the soft oxidizing electrophile, and wherein the oxidizing regeneration reagent oxidizes the electrophile reduction product to the soft oxidizing electrophile in the acidic medium in the presence of the alkane.

22 . The process of claim 1 , wherein the soft oxidizing electrophile comprising a main group element in oxidized form is present in less than stoichiometric quantities relative to the alkane and acts as a catalyst.

23 . (canceled)

24 . The process of claim 1 , wherein no oxidizing regeneration reagent is present in the acidic medium with the soft oxidizing electrophile comprising a main group element in oxidized form, and the soft oxidizing electrophile is present in at least stoichiometric quantities relative to the alkane in the acidic medium.

25 .- 27 . (canceled)

28 . The process of claim 1 , wherein the soft oxidizing electrophile is immobilized on a solid support contained within a reactor.

29 . (canceled)

30 . (canceled)

31 . The process of claim 1 , comprising separating the alkane oxygenate and the electrophile reduction product.

32 . The process of claim 1 , wherein the soft oxidizing electrophile comprises the element iodine in oxidized form.

Assignees

• Reriana Roy
• Hashiguchi Brian G
• Konnick Michael M
• Bishof Steven M
• Scrips Res Inst
• Scripps Research Inst

Inventors

• Periana Roy A
• Hashiguchi Brian G
• Konnick Michael M
• Bischof Steven M

Classifications

• C07C67/035 Primary

  by reacting carboxylic acids or symmetrical anhydrides with saturated hydrocarbons · CPC title