Methods and systems for the formation of cyclic carbonates
Described herein are inventive methods for synthesis of cyclic carbonates from CO 2 and epoxide. In some embodiments, the methods are carried out in the presence of a catalyst comprising an electrophilic halogen. In some embodiments, the methods are carried out in a flow reactor.
1. A method, comprising:
reacting a compound of Formula (I):
with CO 2 in the presence of a catalyst to produce a compound of Formula (II):
wherein R 1 is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heteroalkyl, optionally substituted heteroalkyl, optionally substituted aryl-alkyl, optionally substituted aryl-O-alkyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted alkenyl, and
wherein the catalyst comprises an electrophilic halogen.
2. The method of claim 1 , wherein the reacting is carried out in the presence of a catalyst comprising an amide.
3. The method of claim 2 , wherein the reacting is carried out in the presence of an oxidant.
4. The method of claim 3 , wherein the oxidant also functions as a solvent.
5. The method of claim 1 , wherein the electrophilic halogen is an electrophilic chlorine, electrophilic bromine, or electrophilic iodine.
6. The method of claim 5 , wherein the catalyst comprising an electrophilic bromine is NBS.
7. The method of claim 1 , wherein the reacting is carried out in the presence of a solvent.
8. The method of claim 7 , wherein the solvent is DMF, DMA, NMP, or combinations thereof.
9. The method of claim 3 , wherein the oxidant is DMF, DMA, NMP, or combinations thereof.
10. The method of claim 1 , wherein the reacting is carried out in a flow reactor.
11. The method of claim 1 , wherein the reaction is carried out under conditions suitable for forming a compound of Formula (II) in a percent conversion of greater than about 60% in a period of time of less than about 24 hours.
12. The method of claim 1 , wherein the compound of Formula (II) is chiral.
13. The method of claim 1 , wherein the compound of Formula (II) has an enantiomeric excess greater than about 80%.
14. The method of claim 1 , wherein the reaction is a gas-liquid biphasic reaction.
15. The method of claim 1 , wherein the reacting is not conducted in the presence of a solid support.
16. The method of claim 1 , wherein no portion of the catalyst is associated with a solid support.
17. The method of claim 1 , wherein the reaction is carried out under conditions suitable for forming a compound of Formula (II) in a percent conversion of greater than about 70% in a period of time of less than about 12 hours.
18. The method of claim 1 , wherein the reaction is carried out under conditions suitable for forming a compound of Formula (II) in a percent conversion of greater than about 80% in a period of time of less than about 6 hours.
19. The method of claim 1 , wherein the reaction is carried out under conditions suitable for forming a compound of Formula (II) in a percent conversion of greater than about 90% in a period of time of less than about 1 hour.
20. The method of claim 1 , wherein the reaction is carried out under conditions suitable for forming a compound of Formula (II) in a percent yield of greater than about 70% in a period of time of less than about 1 hour.