Activation of alkyl substrates in condensed phase with ozone
A process for oxidizing an alkyl substrate may comprise combining an alkyl substrate (e.g., propane, n-butane) and ozone in a liquid phase medium comprising a branched alkane activator (e.g., isobutane) and a protic additive (e.g., water) under conditions sufficient to oxidize the alkyl substrate to products. The alkyl substrate may be selected from linear and cyclic alkanes.
1 . A process for oxidizing an alkyl substrate, the process comprising combining an alkyl substrate and ozone in a liquid phase medium comprising a branched alkane activator and a protic additive, wherein the branched alkane activator is a compound capable of reacting with the ozone to form a hydrotrioxide intermediate and the protic additive is a compound capable of forming a hydrogen bond with the hydrotrioxide intermediate, and further wherein the ozone oxidizes the alkyl substrate to products comprising an alcohol, wherein the alkyl substrate is selected from linear and cyclic alkanes.
2 . The process of claim 1 , wherein the alkyl substrate is selected from linear alkanes.
3 . The process of claim 2 , wherein the linear alkanes comprise propane, n-butane, or both.
4 . The process of claim 1 , wherein the branched alkane activator comprises a tertiary carbon.
5 . The process of claim 1 , wherein the branched alkane activator is an isoalkane.
6 . The process of claim 1 , wherein the branched alkane activator has from 4 to 8 carbons.
7 . The process of claim 1 , wherein the branched alkane activator is isobutane.
8 . The process of claim 1 , wherein the branched alkane activator is present in the liquid phase medium at an activator-to-alkyl substrate mole ratio of greater than 0.2 and the protic additive is present in the liquid phase medium at an amount of at least 0.1 mol %.
9 . The process of claim 1 , wherein the branched alkane activator is isobutane and the alkyl substrate comprises propane, n-butane, or both.
10 . The process of claim 1 , further comprising adding the protic additive to the liquid phase medium prior to oxidizing the alkyl substrate.
11 . The process of claim 1 , wherein the protic additive is water, an alcohol having from 1 to 6 carbons, or a combination thereof.
12 . The process of claim 1 , wherein the liquid phase medium comprises no more than 0.4 mol % CO 2 .
13 . The process of claim 1 , wherein the liquid phase medium is free of added CO 2 .
14 . The process of claim 8 , wherein the combining is carried out at a temperature of at least 15° C. and a total pressure of a vapor phase present above the liquid phase medium of no more than 5 MPa.
15 . The process of claim 1 , wherein the products comprise the alcohol at a selectivity of at least 50%, the products comprise CO 2 at a selectivity of no more than 10%, the process has an ozone utilization value of at least 75%, or a combination thereof.
16 . The process of claim 1 , wherein the products comprise the alcohol at a selectivity of at least 50%, the products comprise CO 2 at a selectivity of no more than 10%, and the process has an ozone utilization value of at least 75%.
17 . The process of claim 1 , wherein the alkyl substrate is a linear alkane, and further wherein the liquid phase medium is free of added CO 2 , and the process further comprises adding the protic additive to the liquid phase medium prior to oxidizing the linear alkane.
18 . The process of claim 1 , wherein the branched alkane activator comprises a tertiary carbon; and the protic additive is water, an alcohol having from 1 to 6 carbons, or a combination thereof.
19 . The process of claim 18 , wherein the branched alkane activator is present in the liquid phase medium at an activator-to-alkyl substrate mole ratio of greater than 0.2 and the protic additive is present in the liquid phase medium at an amount of at least 0.1 mol % and wherein the combining is carried out at a temperature of at least 15° C. and a total pressure of a vapor phase present above the liquid phase medium of no more than 5 MPa.
20 . The process of claim 19 , wherein the branched alkane activator has from 4 to 8 carbons and the alcohol is selected from methanol, ethanol, isopropanol, tert-butyl alcohol, and combinations thereof.