Cobalt-catalyzed asymmetric cyclopropanation of alkenes with α-nitrodiazoacetates
A process for the cyclopropanation of olefins with a metal porphyrin catalyst and an acceptor/acceptor substituted diazo reagent.
1. A method for cyclopropanation of an olefin, the process comprising treating an olefin with an electron acceptor substituted nitro diazo reagent in the presence of a chiral cobalt(II) porphyrin complex with D 2 -symmetry.
2. The method of claim 1 wherein the olefin corresponds to Formula 1
wherein R 1 , R 2 , R 3 , and R 4 are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or an electron withdrawing group.
3. The method of claim 1 wherein the olefin is styrene, substituted styrene, an α,β-unsaturated ester, or an α,β-unsaturated ketone.
4. The method of claim 2 wherein at least one of R 1 , R 2 , R 3 , and R 4 is selected from the group consisting of phenyl, t-butylphenyl, tolyl, trifluoromethyl phenyl, nitrophenyl, fluorophenyl, chlorophenyl, bromophenyl, perfluorophenyl, butyl, phenyethyl, methyl carboxylate, ethyl carboxylate, and dimethylcarbamoyl.
5. The method of claim 2 wherein the diazo reagent corresponds to Formula 7
wherein R 10 is an electron acceptor.
6. The method of claim 5 wherein R 10 is selected from the group consisting of an aldehyde, a ketone, an ester, and a carboxylic acid.
7. The method of claim 2 wherein the diazo reagent corresponds to Formula 8
wherein R 11 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, halogen, —OR 20 , —NR a R b , or —OC(O)R 21 , wherein R 20 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo; R a and R b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl or heterocyclo; and R 21 is hydrocarbyl, substituted hydrocarbyl or heterocyclo.
8. The method of claim 2 wherein the diazo reagent corresponds to Formula 9
wherein R 12 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
9. The method of claim 8 wherein R 12 is selected from the group consisting of ethyl, methyl, butyl, or propyl.
10. The method of claim 9 wherein at least one of R 1 , R 2 , R 3 , and R 4 is selected from the group consisting of phenyl, t-butylphenyl, tolyl, trifluoromethyl phenyl, nitrophenyl, fluorophenyl, chlorophenyl, bromophenyl, perfluorophenyl, butyl, phenyethyl, methyl carboxylate, ethyl carboxylate, and dimethylcarbamoyl.
11. The method of claim 1 wherein the method yields a nitro-substituted cyclopropane corresponding to Formula Z
wherein R 1 , R 2 , R 3 , and R 4 are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or an electron withdrawing group; and R 12 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
12. The method of claim 1 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry is selected from the group consisting of
13. The method of claim 2 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry is selected from the group consisting of
14. The method of claim 3 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry is selected from the group consisting of
15. The method of claim 5 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry is selected from the group consisting of
16. The method of claim 7 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry is selected from the group consisting of
17. The method of claim 8 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry is selected from the group consisting of
18. The method of claim 1 wherein the diazo reagent corresponds to Formula 7
wherein R 10 is an electron acceptor.
19. The method of claim 18 wherein R 10 is selected from the group consisting of an aldehyde, a ketone, an ester, and a carboxylic acid.
20. The method of claim 1 wherein the diazo reagent corresponds to Formula 8
wherein R 11 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, halogen, —OR 20 , —NR a R b , or —OC(O)R 21 , wherein R 20 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo; R a and R b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl or heterocyclo; and R 21 is hydrocarbyl, substituted hydrocarbyl or heterocyclo.
21. The method of claim 1 wherein the diazo reagent corresponds to Formula 9
wherein R 12 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
22. The method of claim 21 wherein R 12 is selected from the group consisting of ethyl, methyl, butyl, or propyl.
23. The method of claim 1 wherein the method yields a nitro-substituted cyclopropane corresponding to Formula Z
wherein R 1 , R 2 , R 3 , and R 4 are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocyclo, or an electron withdrawing group; and R 12 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
24. The method of claim 1 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]:
25. The method of claim 18 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]:
26. The method of claim 19 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]:
27. The method of claim 20 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]:
28. The method of claim 21 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]:
29. The method of claim 22 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]:
30. The method of claim 23 wherein the chiral cobalt(II) porphyrin complex with D 2 -symmetry corresponds to Formula [Co(P1)]: