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1 Supporting Information Synthesis of α-(pentafluorosulfanyl)- and α-(trifluoromethyl)-substituted Carboxylic Acid Derivatives by Ireland-Claisen Rearrangement Anna-Lena Dreier, Bernd Beutel, Christian Mück-Lichtenfeld, Andrej V. Matsnev, Joseph S. Thrasher, Günter Haufe*, Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, Münster, Germany Department of Chemistry, Advanced Materials Research Laboratory, Clemson University, 91 Technology Drive, Anderson, South Carolina 29625, United States of America Cells-in-Motion Cluster of Excellence, Universität Münster, Waldeyerstraße 15, Münster, Germany Table of contents Oligomerization reactions 2 Rearrangement of 2-fluoro-3-(pentafluorosulfanylacetoxy)dodecene 6 Methylation of carboxylic acids 14 with K 2 CO 3 /MeI in DMF 7 DFT Calculations 10 Copies of the NMR spectra 20 References 68 S1

2 Oligomerization reactions As an example, 1-phenylprop-2-en-1-yl-(2-pentafluorosulfanyl)acetate (9a) was treated with TMSOTf and trimethylamine in methylene chloride according to the procedure described. 1 Oligomeric products were obtained according to NMR and mass spectra on the following pages. S2

3 Figure S1: 1 H NMR spectrum (CDCl 3 ) of the mixture of oligomeric products formed from 1-phenylallyl-(2-pentafluorosulfanyl)acetate (9a) S3

4 Figure S2: 19 F NMR spectrum (CDCl 3 ) of the mixture of oligomeric products formed from 1-phenylallyl-(2-pentafluorosulfanyl)acetate (9a) S4

5 Figure S3: ESI MS of the mixture of oligomeric products formed from 1-phenylallyl-(2- pentafluorosulfanyl)acetate (9a) S5

6 Rearrangement of 2-fluoro-3-(pentafluorosulfanylacetoxy)dodec-1-ene (1a) The 19 F NMR experiment of the rearrangement of 1a was executed as described in the general procedure given in the experimental part of reference 1 with reverse addition of the reagents. The ester 1a (30 mg, 0.08 mmol, 1 equiv) was dissolved in CD 2 Cl 2 (400 L) in an NMR tube. Et 3 N (30 L, 0.24 mmol, 3.0 equiv) and TMSOTf (20 L, 0.1 mmol, 1.2 equiv) were added successively at room temperature. Another portion of CD 2 Cl 2 (250 L) was added, and after intense mixing, NMR spectra were recorded after certain time intervals. Comparison of the 19 F NMR spectra after 2 hours of reaction time with different order of addition of the reagents is shown in Figure S4. Figure S4: Comparison of the ratio of starting 1a and intermediate (E)- and (Z)-enolates (the (Z)-isomer is the major component) in CD 2 Cl 2 at rt after 2 h of reaction time by 19 F NMR spectroscopy; top: 1. Et 3 N, 2. TMSOTf, bottom: 1. TMSOTf, 2. Et 3 N. S6

7 Methylation of carboxylic acids 8 with K 2 CO 3 /MeI in DMF Two mechanistic alternatives can be offered for the formation of the formyl compounds: (i) a direct nucleophilic substitution after methylation of the carboxyl function forming an iminium cation and elimination of SF 5, which decomposes under the basic conditions. Finally the iminium ion is hydrolyzed during aqueous workup forming the formyl compounds. Alternatively (ii) an -lactone might be formed initially by intramolecular nucleophilic substitution of the SF 5 -group similar to what has been found for other substitutions of - substituted carboxyl compounds. 2 Subsequent ring opening by nucleophilic attack of MF and alkylation of the formed carboxylate group leads to the already mentioned iminium ion, which is hydrolyzed by aqueous workup as mentioned above. Scheme S1. Anticipated mechanism of nucleophilic substitution of the SF 5 with the formate group The diastereomeric ratio is approximately the same as in the starting material. Verification of the mechanistic alternatives was out of the scope of the present investigation. S7

8 Figure S5: 1 H NMR spectrum of formate side product obtained from the alkylation with MeI/K 2 CO 3 in DMF of compound 8f. S8

9 Figure S6: 13 C NMR spectrum of formate side product obtained from the alkylation with MeI/K 2 CO 3 in DMF of compound 8f. S9

10 DFT Calculations Energies of Intermediate Ketene Trimethylsilyl Acetals and Transition States of Ireland- Claisen Rearrangements For each isomer (E/Z) of the intermediately formed ketene trimethylsilyl acetals (KTA) of 7a, A, B and 1b, two transition structures were considered (TS chair and TS boat ) and separately optimized. Reaction products have not been taken into consideration, since the reaction is exothermic and reversal is therefore not relevant. Ketene trimethylsilyl acetals (KTA) of 7a KTA7a Table S1. DFT calculated energies and free energy contribution for the E/Z isomers and transition states for [3,3]-sigmatropic rearrangements of the diastereomeric ketene trimethylsilyl acetals of 7a. E(TPSS-D3) [a] [E h ] E(PW6B95-D3) [b] [E h ] G 298 [c] [kcal/mol] ΔE 0 [d] [kcal/mol] ΔG 298 [e] [kcal/mol] (E)-KTA7a (Z)-KTA7a (E)-TS7a chair (E)-TS7a boat (Z)-TS7a chair (Z)-TS7a boat [a] TPSS-D3/def2-TZVP. Structures were optimized with this method [b] PW6B95-D3/def2-TZVP + COSMO(CH 2 Cl 2 ) single point energies [c] free energy contributions for 298 K using harmonic vibrational frequencies (TPSS-D3/def2-TZVP) [d] relative energies w.r.t. KTA of 7a (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )) at 0 K [e] relative energies w.r.t. KTA of 7a (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )+G 298 ) at 298 K Figure S7: Schematic diagram depicting the relative free energies ΔG 298 in CH 2 Cl 2 of the (E/Z)-isomeric ketene trimethylsilyl acetals of 7a and the transition structures for the Ireland-Claisen rearrangement. S10

11 (E)-KTA7a (Z)-KTA7a (E)-TS7a chair (Z)-TS7a chair (E)-TS7a boat (Z)-TS7a boat Figure S8. DFT-optimized conformations (TPSS-D3/def2-TZVP) of the (E/Z)-isomeric ketene trimethylsilyl acetals (KTA) of 7a and transition structures of Ireland-Claisen rearrangement. Bond lengths in the transition structures are given in Å S11

12 In order to find an explanation for the failure of [3,3]-sigmatropic rearrangements of the aryl compounds of type 9, the energies of the E/Z ketene trimethylsilyl acetals and the respective chair and boat transition states of Ireland-Claisen rearrangements were calculated. In particular a model for the fluorinated compound 1 (X = F) (with CH 3 instead of C 9 H 19 ), the corresponding compound A without vinylic fluorine (model for compound 1 (X = H), and compound 9a. Ketene trimethylsilyl acetals A (model compound for 1, CH 3 instead of C 9 H 19 ) Table S2. DFT calculated energies and free energy contribution for the E/Z isomers and transition states for [3,3]-sigmatropic rearrangements of the diastereomeric ketene trimethylsilyl acetals A E(TPSS-D3) [a] [E h ] A E(PW6B95-D3) [b] [E h ] G 298 [c] [kcal/mol] ΔE 0 [d] [kcal/mol] ΔG 298 [e] [kcal/mol] (E)-A (Z)-A (E)-TSA chair (E)-TSA boat (Z)-TSA chair (Z)-TSA boat [a] TPSS-D3/def2-TZVP. Structures were optimized with this method [b] PW6B95-D3/def2-TZVP + COSMO (CH 2 Cl 2 ) single point energies [c] free energy contributions for 298 K using harmonic vibrational frequencies (TPSS-D3/def2-TZVP) [d] relative energies w.r.t. A (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )) at 0 K [e] relative energies w.r.t. A (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )+G 298 ) at 298 K Figure S9. Schematic diagram depicting the free energies ΔG 298 in CH 2 Cl 2 of (E/Z)-A and transition structures for Ireland-Claisen rearrangement. S12

13 (E)-A (Z)-A (E)-TSA chair (Z)-TSA chair (E)-TSA boat (Z)-TSA boat Figure S10: DFT-optimized conformations (TPSS-D3/def2-TZVP) of (E/Z)-A and transition structures of Ireland-Claisen rearrangement. Bond lengths in the transition structures are given in Å. S13

14 Ketene trimethylsilyl acetals B (model compound, no fluorine in 2-position) B Table S3. DFT calculated energies and free energy contribution for the E/Z isomers and transition structures of B. E(TPSS-D3) [a] [E h ] E(PW6B95-D3) [b] [E h ] G 298 [c] [kcal/mol] ΔE 0 [d] [kcal/mol] ΔG 298 [e] [kcal/mol] (E)-B (Z)-B (E)-TSB chair (E)-TSB boat (Z)-TSB chair (Z)-TSB boat [a] TPSS-D3/def2-TZVP. Structures were optimized with this method [b] PW6B95-D3/def2-TZVP + COSMO (CH 2 Cl 2 ) single point energies [c] free energy contributions for 298 K using harmonic vibrational frequencies (TPSS-D3/def2-TZVP) [d] relative energies w.r.t. B (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )) at 0 K [e] relative energies w.r.t. B (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )+G 298 ) at 298 K Figure S11: Schematic diagram depicting the free energies ΔG 298 in CH 2 Cl 2 of (E/Z)-B and transition structures for Ireland-Claisen rearrangement. S14

15 (E)-B (Z)-B (E)-TSB chair (Z)-TSB chair (E)-TSB boat (Z)-TSB boat Figure S12: DFT-optimized conformations (TPSS-D3/def2-TZVP) of (E/Z)-B and transition structures of Ireland-Claisen rearrangement. Bond lengths in the transition structures are given in Å. S15

16 Ketene trimethylsilyl acetals of 9a KTA 9a Table S4. DFT calculated energies and free energy contribution for the E/Z isomers and transition structures of 9a. E(TPSS-D3) [a] [E h ] E(PW6B95-D3) [b] [E h ] G 298 [c] [kcal/mol] ΔE 0 [d] [kcal/mol] ΔG 298 [e] [kcal/mol] (E)-9a (Z)-9a (E)-TS9a chair (E)-TS9a boat (Z)-TS9a chair (Z)-TS9a boat [a] TPSS-D3/def2-TZVP. Structures were optimized with this method [b] PW6B95-D3/def2-TZVP + COSMO(CH 2 Cl 2 ) single point energies [c] free energy contributions for 298 K using harmonic vibrational frequencies (TPSS-D3/def2-TZVP) [d] relative energies w.r.t. 9a (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )) at 0 K [e] relative energies w.r.t. 9a (PW6B96-D3/def2-TZVP+COSMO(CH 2 Cl 2 )+G 298 ) at 298 K Figure S13: Schematic diagram depicting the free energies ΔG 298 in CH 2 Cl 2 of (E/Z)-9a and transition structures for Ireland-Claisen rearrangement. S16

17 (E)-9a (Z)-9a (E)-TS9a chair (Z)-TS9a chair (E)-TS9a boat (Z)-TS9a boat Figure S14: DFT-optimized conformations (TPSS-D3/def2-TZVP) of (E/Z)-9a and transition structures of Ireland-Claisen rearrangement. Bond lengths in the transition structures are given in Å. S17

18 pk a Values of Four Acetic Acid Methyl Ester Derivatives The estimation of pk a values of the methyl esters of the substituted acetic acids has been achieved by calculating the free energy of proton transfer from the ester (forming the (E)- or (Z)-enolate) to the cyclopentadienyl anion. All structures were optimized in the gas phase (TPSS-D3/def2-TZVP), enthalpic and entropic contributions were obtained from harmonic vibrational frequencies at these stationary points. The electronic energies were then recalculated with TPSS-D3/def2-TZVP using the COSMO implicit solvation model (for CH 2 Cl 2 and DMSO). Using the experimental pk a value of 18.0 for cyclopentadiene, C 5 H 6, we were able to derive a computational prediction for the acidity of the four esters in these solvents. The value for the cyano compound F was determined for comparison. (C: R = CH 3, D: R = CF 3, E: R = SF 5, F: R = CN) (Eq. S1) Table S6. Energies of acetic acid esters C-F and (E)/(Z) enolates derived from these. Cyclopentadiene (C 5 H 6 ) and cyclopentadienyl anion (C 5 H 5ˉ) as reference. E(TPSS-D3) [a] [E h ] E sol (CH 2 Cl 2 ) [b] [E h ] E sol (DMSO) [b] [E h ] G 298 [c] [kcal/mol] C C-(E)-enolate C-(Z)-enolate D D-(E)-enolate D-(Z)-enolate E E-(E)-enolate E-(Z)-enolate F F-(E)-enolate F-(Z)-enolate C 5 H C 5 H [a] TPSS-D3/def2-TZVP. Structures were optimized with this method. [b] TPSS-D3/def2-TZVP + COSMO single point energies (ε(ch 2 Cl 2 ) = 9.08, ε(dmso) = 46.7) [c] free energy contributions for 298 K using harmonic vibrational frequencies (TPSS-D3/def2-TZVP) S18

19 Table S7. pk a values of C-F estimated by calculating free energies of proton transfer reaction (Eq. S1). Reaction free energies are based on the values from Table S5. ΔG 298 (vac) ΔG 298 (CH 2 Cl 2 ) ΔG 298 (DMSO) ΔpK a ΔpK a ΔpK a pk a pk a pk a [kcal/mol] [kcal/mol] [kcal/mol] (vac) (CH 2 Cl 2 ) (DMSO) (vac) (CH 2 Cl 2 ) (DMSO) C (E)-enolate (Z)-enolate D (E)-enolate (Z)-enolate E (E)-enolate (Z)-enolate F (E)-enolate (Z)-enolate [a] ΔpK a (T) = ΔG T /(ln(10)*r*t) [b] pk a = ΔpK a (pk a (C 5 H 6 ) exp = 18.0 in DMSO) S19

20 Figure S15: 1 H NMR spectrum of cinnamyl 2-(pentafluorosulfanyl)acetate (7a). S20

21 Figure S16: 13 C NMR spectrum of cinnamyl 2-(pentafluorosulfanyl)acetate (7a). S21

22 Figure S17: 19 F{ 1 H, 13 C} NMR spectrum of cinnamyl 2-(pentafluorosulfanyl)acetate (7a). S22

23 Figure S18: 1 H NMR spectrum of cinnamyl 3,3,3-trifluoropropanoate (7b). S23

24 Figure S19: 13 C NMR spectrum of cinnamyl 3,3,3-trifluoropropanoate (7b). S24

25 Figure S20: 19 F NMR spectrum of cinnamyl 3,3,3-trifluoropropionate (7b). S25

26 Figure S21: 1 H NMR spectrum of cinnamyl propionate (7c). S26

27 Figure S22: 13 C NMR spectrum of cinnamyl propionate (7c). S27

28 Figure S23: 1 H NMR spectrum of (E)-4-fluorocinnamyl 2-(pentafluorosulfanyl)acetate (7d). S28

29 Figure S24: 13 C NMR spectrum of (E)-4-fluorocinnamyl 2-(pentafluorosulfanyl)acetate (7d). S29

30 Figure S25: 19 F{ 1 H, 13 C} NMR spectrum of (E)-4-fluorocinnamyl 2-(pentafluorosulfanyl)acetate (7d) ppm. S30

31 Figure S26: 19 F{ 1 H, 13 C} NMR spectrum of (E)-4-fluorocinnamyl 2-(pentafluorosulfanyl)acetate (7d) ppm. S31

32 Figure S27: 1 H NMR spectrum of (E)-4-fluorocinnamyl 3,3,3-trifluoropropanoate (7e). S32

33 Figure S28: 13 C NMR spectrum (E)-4-fluorocinnamyl 3,3,3-trifluoropropanoate (7e). S33

34 Figure S29: 19 F NMR spectrum (E)-4-fluorocinnamyl 3,3,3-trifluoropropanoate (7e). S34

35 Figure S30: 1 H NMR spectrum (E)-4-methylcinnamyl 2-(pentafluorosulfanyl)acetate (7f). S35

36 Figure S31: 13 C NMR spectrum (E)-4-methylcinnamyl 2-(pentafluorosulfanyl)acetate (7f). S36

37 Figure S32: 19 F{ 1 H, 13 C} NMR spectrum (E)-4-methylcinnamyl 2-(pentafluorosulfanyl)acetate (7f). S37

38 Figure S33: 1 H NMR spectrum of (E)-4-methylcinnamyl 3,3,3-trifluoropropanoate (7g). S38

39 Figure S34: 13 C NMR spectrum of (E)-4-methylcinnamyl 3,3,3-trifluoropropanoate (7g). S39

40 Figure S35: 19 F NMR spectrum of (E)-4-methylcinnamyl 3,3,3-trifluoropropanoate (7g). S40

41 Figure S36: 19 F NMR of crude acids 8a to determine the diastereomeric ratio. S41

42 Figure S37: 19 F NMR of crude acids 8b to determine the diastereomeric ratio. S42

43 Figure S38: 19 F NMR of crude acids 8d to determine the diastereomeric ratio. S43

44 Figure S39: 19 F NMR of crude acids 8e to determine the diastereomeric ratio. S44

45 Figure S40: 19 F NMR of crude acids 8f to determine the diastereomeric ratio. S45

46 Figure S41: 19 F NMR of crude acids 8g to determine the diastereomeric ratio. S46

47 Figure S42: 1 H NMR spectrum of methyl 2-(pentafluorosulfanyl)-3-phenylpen-4-enoates 15a. S47

48 Figure S43: 13 C NMR spectrum of methyl 2-(pentafluorosulfanyl)-3-phenylpen-4-enoates 15a. S48

49 Figure S44: 19 F{ 1 H, 13 C} NMR spectrum of methyl 2-(pentafluorosulfanyl)-3-phenylpen-4-enoates 15a. S49

50 Figure S45: 1 H NMR spectrum of methyl 3-phenyl-2-(trifluoromethyl)pent-4-enoates 15b. S50

51 Figure S46: 13 C NMR spectrum of methyl 3-phenyl-2-(trifluoromethyl)pent-4-enoates 15b. S51

52 Figure S47: 19 F { 1 H, 13 C} NMR spectrum of methyl 3-phenyl-2-(trifluoromethyl)pent-4-enoates 15b. S52

53 Figure S48: 1 H NMR spectrum of methyl 2-methyl-3-phenylpen-4-enoates 15c. S53

54 Figure S49: 13 C NMR spectrum of methyl 2-methyl-3-phenylpen-4-enoates 15c. S54

55 Figure S50: 1 H NMR spectrum of methyl 3-(4-fluorophenyl)-2-(pentafluorosulfanyl)pent-4-enoates 15d. S55

56 Figure S51: 13 C NMR spectrum of methyl 3-(4-fluorophenyl)-2-(pentafluorosulfanyl)pent-4-enoates 15d. S56

57 Figure S52: 19 F{ 1 H, 13 C} NMR spectrum of methyl 3-(4-fluorophenyl)-2-(pentafluorosulfanyl)pent-4-enoates 15d; ppm. S57

58 Figure S53:: 19 F{ 1 H, 13 C} NMR spectrum of methyl 3-(4-fluorophenyl)-2-(pentafluorosulfanyl)pent-4-enoates 15d; -200 to -10 ppm. S58

59 Figure S54: 1 H NMR spectrum of methyl 3-(4-fluorophenyl)-2-(trifluoromethyl)pent-4-enoates 15e. S59

60 Figure S55: 13 C NMR spectrum of methyl 3-(4-fluorophenyl)-2-(trifluoromethyl)pent-4-enoates 15e. S60

61 Figure S56: 19 F { 1 H, 13 C} NMR spectrum of methyl 3-(4-fluorophenyl)-2-(trifluoromethyl)pent-4-enoates 15e. S61

62 Figure S57: 1 H NMR spectrum of methyl 2-(pentafluorosulfanyl)-3-(p-tolyl)pent-3-enoates 15f. S62

63 Figure S58: 13 C NMR spectrum of methyl 2-(pentafluorosulfanyl)-3-(p-tolyl)pent-3-enoates 15f. S63

64 Figure S59: 19 F NMR spectrum of methyl 2-(pentafluorosulfanyl)-3-(p-tolyl)pent-3-enoates 15f. S64

65 Figure S60: 1 H NMR spectrum of methyl 3-(p-tolyl)-2-(trifluoromethyl)pent-4-enoates 15g. S65

66 Figure S61: 13 C NMR spectrum of methyl 3-(p-tolyl)-2-(trifluoromethyl)pent-4-enoates 15g. S66

67 Figure S62: 19 F NMR spectrum of methyl 3-(p-tolyl)-2-(trifluoromethyl)pent-4-enoates 15g. S67

68 References (1) A.-L. Dreier, A. V. Matsnev, J. S. Thrasher, G. Haufe, J. Fluorine Chem. 2014, 167, (2) C. F. Rodriquez, I. H. Williams, J. Chem. Soc., Perkin Trans , and refs. cited therein S68

Phospha-Claisen Type Reactions at Frustrated Lewis Pair. Supporting Information

Phospha-Claisen Type Reactions at Frustrated Lewis Pair Frameworks Guo-Qiang Chen, Gerald Kehr, Christian Mück-Lichtenfeld, Constantin G. Daniliuc, Gerhard Erker* Organisch-Chemisches Institut, Universität