Process for catalytic hydrodefluorodimerization of fluoroölefins
The present application provides a hydrodefluorodimerization process, which is useful in the synthesis of, for example, fluoroölefins that can be used as refrigerants, blowers and the like. The process is an “early-stage fluorination” process, wherein precursors containing fluorine are assembled into the desired product using a zerovalent nickel catalyst. Also provided is a liquid composition comprising one or more fluoroölefin produced by this catalytic process.
1. A process for preparing a hydrofluoroölefin of Formula II
comprising:
treating a compound of Formula I with a hydride source, a ligand and nickel[0] catalyst
where R 1 , R 2 and R 3 are each independently H, F, R F , n-alkyl, isoalkyl, tert-alkyl, cycloalkyl, aryl, alkenyl, NR 2 , OR, SR, or R 3 Si, where R is an n-alkyl, isoalkyl, tert-alkyl, cycloalkyl, aryl, or alkenyl.
2. The process of claim 1 , wherein the ligand is a phosphine or an N-heterocyclic carbine.
3. The process of claim 1 , wherein the ligand is a compound of Formula IV, V, VI, or VII,
wherein each of R 4 -R 9 is independently n-alkyl, iso-alkyl, ter-alkyl, cycloalkyl, aryl, silyl, or dialkylamino;
each of R 10 and R 11 is independently n-alkyl, iso-alkyl, ter-alkyl, cycloalkyl, aryl, silyl, dialkylamino, or (alkylamino)methyl;
each of R 12 and R 13 is independently n-alkyl, iso-alkyl, ter-alkyl, cycloalkyl, aryl, silyl, or a hydrogen atom;
R 14 is independently n-alkyl, iso-alkyl, ter-alkyl, cycloalkyl, aryl, silyl, or a hydrogen atom;
Z is O, S, N(R 8 ) or CR 8 R 9 ;
each Z′ is independently N or C,
and wherein dashed lines represent optional bonds.
4. The process of claim 1 , wherein the nickel[0] catalyst is formed in situ from a divalent nickel salt and a reducing agent.
5. The process of claim 1 , wherein the hydride source is a silane or mixture of H 2 and a base.
6. The process of claim 5 , wherein the silane has the formula R′ 3 SiH, where R′ is n-alkyl, isoalkyl, cycloalkyl, aryl, alkenyl, NR 2 , OR, or R 3 Si.
7. The process of claim 1 , where the fluoroalkene is vinylidene difluoride, trifluoroethylene (HFO-1123), vinyl fluoride (HFO-1141),2,3,3,3-tetrafluoropropylene (HFO-1234yf), and 1,3,3,3-tetrafluoropropylene (HFO-1234ze), or any combination thereof.
8. The process of claim 1 , wherein the process is used to produce 2,4,4-trifluorobut-1-ene (HFO-1363pyf).
9. The process of claim 1 , wherein the process is performed in a solvent having a boiling point between about 80° C. and about 300° C., or between about 110° C. and about 200° C.
10. The process of claim 1 , wherein the process is performed at a temperature of from between about 25° C. and about 150° C., or between about 45° C. and about 110° C.
11. The process of claim 1 , wherein the process additionally comprises separating the hydrofluoroölefin product from the reaction mixture by vacuum distillation.
12. The process of claim 1 , wherein the process additionally comprises purification of the hydrofluoroölefin product, optionally, by cryogenic distillation.