Highly robust efficient catalyst for selective dehydrogenation of neat glycerol to lactic acid

• US 10,202,327 B2
• Filed: 02/02/2017
• Issued: 02/12/2019
• Est. Priority Date: 02/02/2016
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Williams, Travis J., Lu, Zhiyao, Demianets, Ivan
• Primary Examiner(s): Orlando, Amber R
• Assistant Examiner(s): Iqbal, Syed I
• Application Number:
  US15/422,728
• Publication Number:
  US 20170217870A1
• Time in Patent Office: 740 Days
• CPC Class Codes: B01J 2231/763 of -CH-XH (X= O, NH/N, S) to -C=X or -CX triple bond species
• CPC Class Codes: B01J 2531/827 Iridium
• CPC Class Codes: B01J 31/2295 Cyclic compounds, e.g. cyclopentadienyls
• CPC Class Codes: C01B 2203/0277 containing a catalytic decomposition step
• CPC Class Codes: C01B 2203/1041 Composition of the catalyst
• CPC Class Codes: C01B 2203/1223 Methanol
• CPC Class Codes: C01B 3/22 by decomposition of gaseous or liquid organic compounds C01B3/0005 takes precedence ; coking liquid carbonaceous materials C10B55/00
• CPC Class Codes: C01D 7/14 Preparation of sesquicarbonates
• CPC Class Codes: C07C 51/16 by oxidation C07C51/145 takes precedence
• CPC Class Codes: C07C 51/295 with inorganic bases, e.g. by alkali fusion
• CPC Class Codes: C07C 59/08 Lactic acid
• CPC Class Codes: C07F 15/0033 Iridium compounds

Abstract

A catalyst system includes a complex having formula I which advantageously has a sterically protecting N-heterocyclic carbene (NHC) carbene-pyridine ligand to handle harsh reactions conditions than many prior art catalysts:

wherein M is a transition metal; o is 0, 1, 2, 3, or 4; R₁ is a C_1-6 alkyl, a C_6-18 aryl, or an optionally substituted C_5-18 heteroaryl. In a refinement, R₁ is methyl, ethyl, butyl, n-propyl, isopropyl, n-butyl, sec-butyl, or t-butyl; R₂, R₃, R₃′ are independently an optionally substituted C_1-6 alkyl, halo (e.g., Cl, F, Br, etc), NO₂, an optionally substituted C_6-18 aryl, or an optionally substituted C_5-18 heteroaryl; R₄, R₄′ are independently an optionally substituted C_1-6 alkyl, halo, NO₂, an optionally substituted C_6-18 aryl, or an optionally substituted C_5-18 heteroaryl; and X⁻ is a negatively charge counter ion and L₁, L₂ are each independently a neutral ligand.

Claims

1. An organometallic complex having formula I:

2. The organometallic complex of claim 1 wherein M is a metal selected from the group consisting of beryllium, magnesium, aluminum, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolimium, terbium, dysprosium, holmium, erbium, thalium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, gold, platinum, thallium, lead, bismuth, polonium, thorium, protactinium, uranium, neptunium, and plutonium.

3. The organometallic complex of claim 1 wherein M is a transition metal selected from the group consisting of ruthenium, rhodium, iridium, and iron.

4. The organometallic complex of claim 1 wherein M is iridium.

5. The organometallic complex of claim 1 wherein R₁ is mesityl, methyl, ethyl, butyl, n-propyl, isopropyl, n-butyl, sec-butyl, or t-butyl.

6. The organometallic complex of claim 1 wherein R₁ is mesityl or methyl.

7. The organometallic complex of claim 1 wherein R₂ are independently an optionally substituted C_1-6 alkyl, halo, NO₂, a C_6-18 aryl, or C_5-18 heteroaryl.

8. An organometallic complex having formula III:

9. The organometallic complex of claim 8 wherein M is a metal selected from the group consisting of beryllium, magnesium, aluminum, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolimium, terbium, dysprosium, holmium, erbium, thalium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, gold, platinum, thallium, lead, bismuth, polonium, thorium, protactinium, uranium, neptunium, and plutonium.

10. The organometallic complex of claim 8 wherein M is a transition metal selected from the group consisting of ruthenium, rhodium, iridium, and iron.

11. The organometallic complex of claim 8 wherein M is iridium.

12. The organometallic complex of claim 8 having formula IV:

13. The organometallic complex of claim 8 having formula V:

14. A method for dehydrogenation a polyol having formula VI:

15. The method of claim 14 wherein the polyol is glycerol and the oxidized compound having formula III is lactic acid.

16. The method of claim 14 wherein the organometallic complex having formula IV OR V:

17. A method for dehydrogenation of an alcohol:

contacting an alcohol having formula R₆OH with a catalyst system that includes an organometallic complex having formula I to form an oxidized compound or to liberate hydrogen;

18. The method of claim 17 wherein the alcohol is methanol.

19. The method of claim 17 wherein the organometallic complex having formula IV or V: