Reaction Progress Kinetics Analysis of 1,3-Disiloxanediols as Hydrogenbonding

Transcription

1 Supporting Information for: Reaction Progress Kinetics Analysis of 1,3-Disiloxanediols as Hydrogenbonding Catalysts Kayla M. Diemoz, Jason E. Hein, Sean O. Wilson, James C. Fettinger, Annaliese K. Franz* Department of Chemistry, One Shields Avenue, University of California, Davis, CA I. Michael Addition Reaction S2 II. Determination of Relative Rates using 19 F NMR Spectroscopy III. Reaction Progress Kinetics Analysis and Variable Time Normalization Analysis using 19 F NMR Spectroscopy IV. 19 F NMR Spectroscopy to Measure Rate Effects of Nitrobenzene Additive S5 S15 S39 V. Reaction monitoring using 1 H NMR Spectroscopy S43 VI. Michael Addition Competition Experiments VII. Derivation of Rate Law VIII. 1,3-Disiloxanediol Binding Studies using 1 H NMR Spectroscopy IX. X-Ray Crystallographic Structures and Information S46 S47 S48 S52 X. Copies of 1 H and 13 C NMR spectra S56 S1

2 Ia. Michael Addition Reaction Table S1. Summary of conditions tested for indole addition to trans-β-nitrostyrene NO 2 catalyst N H solvent, NO 2 23 C 8a 9a 1a entry catalyst solvent time yield (%) a 1 none DCM 24 h 5 2 3a (2 mol %) DCM 24 h a (2 mol %) DCM 24 h (2 mol %) DCM 24 h 1 5 none o-dcb 24 h 2 5 3a (2 mol %) o-dcb 24 h 96 (95) b 6 3a (1 mol %) o-dcb 24 h a (5 mol %) o-dcb 6 h a (5 mol %) o-dcb 7 d b (2 mol %) o-dcb 24 h 99 (96) b 1 3b (1 mol %) o-dcb 24 h b (1 mol %) o-dcb 12 h c (2 mol %) o-dcb 24 h c (1 mol %) o-dcb 24 h d (1 mol %) o-dcb 24 h d (5 mol %) o-dcb 24 h e (1 mol %) o-dcb 24 h 91 (97) b 17 3e (5 mol %) o-dcb 24 h e (5 mol %) o-dcb 6 h 72 (81) b 19 2a (2 mol %) o-dcb 24 h b (2 mol %) o-dcb 24 h c (2 mol%) o-dcb 24 h (2 mol%) o-dcb 24 h (2 mol %) 6 (2 mol %) o-dcb o-dcb 48 h 24 h none none 24 h b (5 mol %) none 24 h e (1 mol %) none 24 h e (5 mol %) none 24 h e (1 mol %) none 12 h (2 mol %) none 24 h 96 a Yields determined using 1 H NMR spectroscopy with SiMe 3 Ph as an internal standard. b Isolated yields determined after column chromatography. NH S2

3 1b. Michael Reaction Recycling Experiment Using 1,3-disiloxanediol 3a, the general procedure was followed, using a scale twice as large: catalyst 3a (63 mg,.15 mmol,.2 equiv), trans-β-nitrostyrene (8a) (.1 g,.76 mmol, 1. equiv), indole (9a) (.13 g, 1.1 mmol, 1.5 equiv) and.4 ml of o-dcb. After the reaction was allowed to run for 24 h, the crude reaction mixture was loaded directly onto a silica column. A solvent mixture of hexane/dcm (1:1) was used to elute any excess starting material and product and then the catalyst was eluted from the column using ethyl acetate. 1,3-disiloxanediol was recovered in high purity in 92% yield (58 mg). Figure S1. 1 H NMR spectra of 1,3-disiloxanediol 3a after isolation from the crude reaction mixture. S3

4 II. Determination of Relative Rates using 19 F NMR spectroscopy IIA. General procedure for monitoring addition of N-methyl indole (9b) to 4- trifluoromethyl-trans-β-nitrostyrene (8b): F 3 C NO 2 N catalyst (1 mol %) CD 2 Cl 2, 23 C 8b 9b F 3 C 1b N NO 2 Experiments to measure relative rates were performed with [8b] = 2. M and [9b] = 3. M for all reactions, except with thiourea catalyst 1a which was performed with [8b] =.2 M and [9b] =.3 M. A stock solution was made with 4-trifluoromethyl-trans-β-nitrostyrene 8b (3.2 M) and fluorobenzene (.5 M) in CD 2 Cl 2. The catalyst (.14 mmol) was dissolved in.44 ml of the stock solution and transferred to an oven-dried and argon-purged NMR tube. An initial 19 F NMR scan was taken before the addition of N-methylindole 9b (.26 ml, 1.5 equiv) and then the reaction was monitored by taking a spectrum every 3 6 minutes. 4 scans with a 25 second relaxation delay were taken to assure complete relaxation for accurate integrations. Fluorobenzene was used as an internal standard ( 113 ppm). Integration ranges for 4- trifluoromethyl-trans-β-nitrostyrene = 62.9 to 63. ppm; product = 62.1 to 62.3 ppm; and internal standard = 113. to ppm. F 3C NO 2 NO 2 F 3C N F Figure S2. Example of 19 F NMR spectrum collected for monitoring the consumption of 4- trifluoromethyl-trans-β-nitrostyrene and formation of product. S4

5 Figure S3. Example of 19 F NMR spectra collected over the course of the reaction monitoring the consumption of 4-trifluoromethyl-trans-β-nitrostyrene and formation of product. Fluorobenzene was used as an internal standard ( 113 ppm). Concentration of starting material and product were calculated based off the raw integrals.!" =!"#$%&'(!"!"#$%&#'$(!(/! [!"#$%$&'()'(']!"#$%&'(!"!"#$%$&'()'(' (equation S1)!"# =!"#$%&'(!"!"#$%&'/! [!"#$%$&'()'(']!"#$%&'(!"!"#$%$&'!"#!# (equation S2) k obs were calculated by taking the ln[8b], linear lines were observed with high R 2 for all catalysts. k cat and k rel were calculated according to the following formulas. k cat = k obs -k background (equation S3) k rel = k cat /k background (equation S4) S5

6 IIb. Kinetic data Background rate in CD 2 Cl 2 : Table S2. Data from monitoring the uncatalyzed reaction using 19 F NMR spectroscopy. Time (min) [8b] M [1b] M % 8b ln[8b] A B Concentration (M) [SM] [P] [SM] + [P] Time (min) ln[8b] y = -.197x R² = Time (min) Figure S4. Data graphed for uncatalyzed reaction: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S6

7 CF 3 CF 3 F 3 C N H S N H CF 3 1a Kinetic experiment with catalyst 1a was performed at a lower concentration due to the limited solubility of thiourea 1a. The reaction was performed with [8a] =.2 M using the above procedure with stock solutions of 4-trifluoromethyl-trans-β-nitrostyrene (8b) (.32 M) and fluorobenzene (.5 M), catalyst (.14 mmol) and N-methylindole (9b) (.26 ml, 1.5 equiv). Table S3. 19 F NMR data from monitoring the reaction catalyzed using thiourea 1a. Time (min) [8b] M [1b] M % 8b ln[8b] A Concentration (M) Time (min) [SM] [P] [SM] + [P] B ln[8b] y = x R² = Time (min) Figure S5. Data graphed for reaction catalyzed by thiourea 1a: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S7

8 Ph N H S N H Ph 1b Table S4. 19 F NMR data from monitoring the reaction catalyzed using thiourea 1b. Time (min) [8b] M [1b] M % 8b ln[8b] A B Concentration (M) [SM] [P] [SM] + [P] Time (min) Figure S6. Data graphed for reaction catalyzed by thiourea 1b: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S8 Ln[8b] y = -.352x R² = Time (min)

9 Np Np Si HO OH 2c Table S5. 19 F NMR data from monitoring the reaction catalyzed using silanediol 2c. Time (min) [8b] M [1b] M % 8b ln[8b] A B Concentration (M) Time (min) [SM] [P] [SM] + [P] ln[8b] y = x R² = Time (min) Figure S7. Data graphed for reaction catalyzed by silanediol 2c: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S9

10 Ph Ph Si O OH Ph Si Ph OH 3a Table S6. 19 F NMR data from monitoring the reaction catalyzed using disiloxanediol 3a. Time (min) [8b] M [1b] M % 8b ln[8b] A B Concentration (M) [SM] [P] [SM] + [P] Time (min) ln[8b] y = -.345x R² = Time (min) Figure S8. Data graphed for reaction catalyzed by disiloxanediol 3a: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S1

11 Np Np Si O Np Si Np OH OH 3b Table S7. 19 F NMR data from monitoring the reaction catalyzed using disiloxanediol 3b. Time (min) [8b] M [1b] M % 8b ln[8b] A B 2.5 Concentration (M) [SM] [P] [SM] + [P] ln[8] y = x R² = Time (min) Time (min) Figure S9. A: Data graphed for reaction catalyzed by disiloxanediol 3b: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S11

12 F F O Si Si OH OH 3d Table S8. 19 F NMR data from monitoring the reaction catalyzed using disiloxanediol 3d. Time (min) [8b] M [1b] M % 8b ln[8b] A B Concentration (M) [SM] [P] [SM] + [P] ln[8b] y = x R² = Time (min) Time (min) Figure S1. Data graphed for reaction catalyzed by disiloxanediol 3d: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S12

13 F F O Ph Si Si Ph OH OH 3e Table S9. 19 F NMR data from monitoring the reaction catalyzed using disiloxanediol 3e. Time (min) [8b] M [1b] M % 8b ln[8b] Concentration (M) A 1 [SM] [P] [SM] + [P] y = x R² = ln[8b] B Time (min) Time (min) Figure S11. Data graphed for reaction catalyzed by disiloxanediol 3e: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. S13

14 Ph Ph Si Ph OH 4 Table S1. 19 F NMR data from monitoring the reaction catalyzed using silanol 4. Time (min) [8b] M [1b] M % 8b ln[8b] Concentration (M) A [SM] [P] [SM] + [P] Time (min) Figure S12. Data graphed for reaction catalyzed by silanol 4: A) Graph of concentration vs. time. B) Graph of ln[8b] vs. time. B ln[8b] y = -.58x R² = Time (min) S14

15 Table S11. Rate data for all catalysts studied. Catalyst k obs k cat k rel None.197 1a b b a b d e III. Reaction Progress Kinetics Analysis 1,2 and Variable Time Normalization Analysis 3 using 19 F NMR Spectroscopy IIIa. General procedure for monitoring addition of N-methylindole 9b to 4-trifluoromethyltrans-β-nitrostyrene 8b: A stock solution was made with catalyst 3a (.53 M) and a second stock solution was made containing both fluorobenzene (.5 M) and 4-trifluoromethyl-trans-β-nitrostyrene 8b (3.46 M). The desired amount of each stock solution and CD 2 Cl 2 were transferred to an oven-dried and argon-purged NMR tube. An initial 19 F NMR spectrum was taken before the addition of N- methylindole 9b and then the reaction was monitored by taking a spectrum every 3-6 minutes. 4 scans with a 25 second relaxation delay were taken to assure complete relaxation for accurate integrations. Fluorobenzene was used as an internal standard ( 113. ppm). Concentration of starting material and product were calculated based off the raw integrals using equations S1 and S2. Overall first order was observed, k obs were calculated by taking the ln[sm], best fit lines were observed with high R 2 for all catalysts. IIIb. Varied Concentrations of 4-trifluoromethyl-trans-β-nitrostyrene 8b Experiments were performed following the general procedure using the amounts of stock solution shown in Table S12. 1 Blackmond, D. G. Angew. Chem., Int. Ed. 25, 44, Blackmond, D. G. J. Am. Chem. Soc. 215, 137, Burés, J. Angew. Chem., Int. Ed. 216, 55, S15

16 Table S12. Amounts used for experiments with varied initial concentration of 4-trifluoromethyltrans-β-nitrostyrene 8b. Trial [8b] M [9b] M [3a] M 8b stock 3a stock CD 9b (ml) 2 Cl 2 (ml) (ml) (ml) S S S Table S F NMR data from monitoring trial S1. Time(min) [8b] M [1b] M ln[8b] S16

17 Table S F NMR data from monitoring trial S2. Time(min) [8b] M [1b] M ln[8b] Table S F NMR data from monitoring trial S3. Time(min) [8b] M [1b] M ln[8b] S17

18 [8b] M [8b]ini = 1.5M [9b]ini = 2.25M [8b]ini = 1.1M Time (min) Figure S13. Graph of concentration vs time for trials S1 S3, overall first order behavior was observed initial rate [8b] ini (M) Figure S14. Graph of initial rate vs [8b] o time for trials S1-S3. S18

19 IIIc. Varied Concentrations of N-methylindole 9b Experiments were performed following the general procedure using the amounts of stock solution shown in the table. Table S16. Amounts used for experiments with varied initial concentration of 9b. Trial [8b] M [9b] M [3a] M 8b stock 3a stock CD 9b (ml) 2 Cl 2 (ml) (ml) (ml) S S S Table S F NMR data from monitoring trial S4. Time(min) [8b] M [1b] M ln[8b] S19

20 Table S F NMR data from monitoring trial S5. Time(min) [8b] M [1b] M ln[8b] [8b] M [9b]ini = 2.25M [9b]ini = 2.M [9b]ini = 1.8M Time (min) Figure S15. Graph of concentration vs time for trials S2, S4, S5, overall first order behavior was observed. S2

21 .25.2 initial rate [9b] ini (M) Figure S16. Graph of initial rate vs [9b] o time for trials S2,S4, S5. IIId. 3-Point rate analysis (Figure 4a and 4b) For the RPKA analysis, 3-point rates were calculated by taking a linear regression of three points and taking the derivative of the line and using that as an estimate for the rate of the middle point. Table S19. 3-point rate analysis of trial S1. Time [8b] M [1b] M d[1b]/dt S21

22 Table S2. 3-point rate analysis of trial S2. Time [8b] M [1b] M d[1b]/dt Table S21. 3-point rate analysis of trial S3. Time (min) [8b] M [1b] M d[1b]/dt S22

23 Table S22. 3-point rate analysis of trial S4. Time (min) [8b] M [1b] d[1b]/dt Table S23. 3-point rate analysis of trial S5. Time (min) [8b] M [1b] d[1b]/dt S23

24 d[1b]/dt X 1 4 (M s -1 ) [8b] = 1.5 M [8b] = 1.2 M [8b] = 1.1 M [9b] M Figure S17. RPKA plot showing rate as a function of N-methylindole 9b with varying [8b]. [9b] = 2.25 M and catalyst [3a] =.15 M for all experiments. d[1b]/dt X 1 4 (M s -1 )/ [8b] [9b] M [8b] = 1.5 M [8b] = 1.2 M [8b] = 1.1 M Figure S18. RPKA plot showing rate as a function of N-methylindole 9b with varying [8b]. [9b] = 2.25 M and catalyst [3a] =.15 M for all experiments. S24

25 IIIe. VTNA analysis of different excess experiment [1b] M [NS] = 1.5 M [NS] = 1.2 M [NS] = 1.1 M Σ[9a] 1 Δt Figure S19. VTNA for trials S1, S2 and S3 showing product concentration as a function of time with varying nitrostyrene [8b]. [9b] = 2.25 M and catalyst [3a] =.15 M for all experiments Overlap is observed with an exponent of 1 in the normalized time scale indicating first order behavior in 8b [1b] M [NS] = 1.5 M [NS] = 1.2 M [NS] = 1.1 M Σ[9a] Δt Figure S2. VTNA for trials S1, S2 and S3 showing product concentration as a function of time with varying nitrostyrene [8b]. [9b] = 2.25 M and catalyst [3a] =.15 M for all experiments No overlap is observed with an exponent of in the normalized time scale. S25

26 IIIf. Varied Concentrations of N-methylindole 9b as limiting reagent Experiments were performed following the general procedure using the amounts of stock solution shown in Table S24. Stock solution of 8b was 3.79 M. Table S24. Amounts used for experiments with varied initial concentration of 9b. Trial [8b] M [9b] M [3a] M 8b stock 3a stock CD 9b (ml) 2 Cl 2 (ml) (ml) (ml) S S S Table S F NMR data from monitoring trial S6. Time (min) [8b] M [1b] M ln[8b] S26

27 Table S F NMR data from monitoring trial S7. Time (min) [8b] M [1b] M ln[8b] Table S F NMR data from monitoring trial S8. Time (min) [8b] M [1b] M ln[8b] S27

28 2.5 2 [8b] (M) [9b]ini = 1.5M [9b]ini = 1.2M [9b]ini = 1.1M y = -.17x y = -.18x y = -.18x Time (min) Figure S21. Initial rate (as denoted by the tangent of the reaction profile for the first five data points) for trials S6, S7 and S8. [8b] = 2. M and catalyst [3a] =.15 M for all experiments All plots for an identical rate of starting material show the rate does not depend on 9b..3 d[1b]/dt (M s -1 ) [9b] = 1.1M [9b] = 1.2M [9b] = 1.5M [8b] (M) Figure S22. RPKA plot showing rate as a function of 8b with varying [9b] for trials S6, S7. S8. [8b] = 2. M and catalyst [3a] =.15 M for all experiments. No difference is observed with varying the indole concentration further supporting that the rate of the reaction does not depend on indole. S28

29 2.5 [8b] M [9b] = 1.5 M [9b] = 1.2 M [9b] = 1.1 M Σ[9a] Δt Figure S23. VTNA for trials S6, S7 and S8 showing product concentration as a function of time with varying nitrostyrene [9b]. [8b] = 2. M and catalyst [3a] =.15 M for all experiments. Better overlap is observed with an exponent of (compared to an exponent of 1, figure S24) in the normalized time scale indicating zero order behavior in 9b [8b] (M) [9b] = 1.5 M [9b] = 1.2 M [9b] = 1.1 M Σ[9a] 1 Δt Figure S24. VTNA for trials S6, S7 and S8 showing product concentration as a function of time with varying nitrostyrene [9b].. [8b] = 2. M and catalyst [3a] =.15 M for all experiments. Poor overlap is observed with an exponent of 1 (compared to an exponent of, figure S23) in the normalized time scale indicating zero order behavior in 9b. S29

30 IIIg. Same Excess Experiments (Figure 5) Following the same excess experiment protocol from RPKA 2,3 the following three experiments were preformed, always keeping the same excess between [8b] and [9b]. Table S28. Amounts used for same excess experiments. Trial [8b] M [9b] M [3a] M 8b stock 9b stock 3a stock CD 2 Cl 2 (ml) (ml) (ml) (ml) Table S F NMR data from monitoring trial 1. Time (min) [8b] M [1b] M S3

31 Table S3. 19 F NMR data from monitoring trial 2. Time (min) [8b] M [1b] M Adjusted time (min) S31

32 Table S F NMR data from monitoring trial 3. Time (min) [8b] M [1b] M Adjusted time(min) IVh. Varied Catalyst Concentration Experiments (Figure 6) Experiments were performed following the general procedure using the amounts of stock solution shown in the table. Table S32. Amounts used for experiments with varied initial concentration of 8b. Trial [8b] [9b] M [3a] 8b Stock 9b (ml) 3a stock CD 2 Cl 2 k obs M M (ml) (ml) (ml) S S S S S a S a a Catalyst stock solution of.7 M was used S32

33 Table S F NMR data from monitoring trial S9. Time (min) [8b] M [1b] M % 78 ln[8b] Ln[8b] y = -.35x R² = Time (min) Figure S25. ln[8b] vs. time for trial S9. S33

34 Table S F NMR data from monitoring trial S1. Time (min) [8b] M [1b] M % 8b ln[8b] ln[8b] y = -.444x R² = Time (min) Figure S26. ln[8b] vs. time for trial S1. S34

35 Table S F NMR data from monitoring trial S11. Time (min) [8b] M [1b] M % 8b ln[8b] Ln[8b] y = -.164x R² = Time (min) Figure S27. ln[8b] vs. time for trial S11. S35

36 Table S F NMR data from monitoring trial S12. Time (min) [8b] M [1b] M % 8b ln[1b] Ln[8b] y = -.314x R² = Time (min) Figure S28. ln[8b] vs. time for trial S12. S36

37 Table S F NMR data from monitoring trial S13. Time (min) [8b] M [1b] M % 8b ln[8b] Ln[8b] y = x R² = Time (min) Figure S29. ln[8b] vs. time for trial S13. S37

38 Table S F NMR data from monitoring trial S14. Time (min) [8b] M [1b] M % 8b ln[1b] Ln[8b] y = x R² = Time (min) Figure S3. ln[8b] vs. time for trial S14. S38

39 4 k obs X 1 4 (min -1 ) [3a] (M) Figure S31. Correlation between apparent first order rate constants and catalyst (3a) concentration. IV. 19 F NMR Spectroscopy to measure rate effects of nitrobenzene additive (Figure 7) A stock solution was made with 4-trifluoromethyl-trans-β-nitrostyrene 8b (4.7 M) and fluorobenzene (.5 M) in CD 2 Cl 2. Disiloxanediol 3a (.14 mmol,.58 g) was dissolved in.3 ml of the stock solution and transferred to an oven-dried and argon-purged NMR tube, followed by the addition of nitrobenzene and CD 2 Cl 2 (See Table). An initial 19 F NMR scan was taken before the addition of N-methylindole 9b (.26 ml, 1.5 equiv) and then the reaction was monitored by taking a spectrum every 3-6 minutes. 4 scans with a 25 second relaxation delay were taken to assure complete relaxation for accurate integrations. Fluorobenzene was used as an internal standard ( 113. ppm). Concentration of starting material and product were calculated based off the raw integrals using equations S1 and S2. Table S39. Amounts used for experiments with nitrobenzene additive Trial [8b] M Equiv nitrobenzene Nitrobenzene (ml) CD 2 Cl 2 (ml) S S S S39

40 Table S4. 19 F NMR data from monitoring trial S15. Time (min) [8b] M [1b] M ln[8b] ln[8b] y = x R² = Time (min) Figure S32. ln[8b] vs. time for trial S15. K rel of relative to reaction background (Figure S3). S4

41 Table S F NMR data from monitoring trial S16. Time (min) [8b] M [1b] M ln[8b] ln[8b] y = -.344x R² = Time (min) Figure S33. ln[8b] vs. time for trial S16. K rel of relative to reaction background (Figure S3). S41

42 Table S F NMR data from monitoring trial S17. Time (min) [8b] M [1b] M ln[8b] ln[8b] y = x R² = Time (min) Figure S34. ln[8b] vs. time for trial S17. K rel of relative to reaction background (figure S3). S42

43 V. Reaction monitoring using 1 H NMR spectroscopy NO 2 3a (1 mol %) NO 2 N CD 2 Cl 2 N 8a 9b 1c Additional experiments were performed using trans-β-nitrostyrene 8a to determine whether the trifluoromethyl group has a significant enough effect on the rate of the reaction to change the mechanism. The reaction with trans-β-nitrostyrene 8a was monitored using 1 H NMR spectroscopy and compared to the kinetic data obtained with 4-trifluoromethyl-trans-βnitrostyrene 8b. As seen in figure S26, when the reaction is catalyzed using 3a the addition of N- methylindole 9b to unsubstituted trans-β-nitrostyrene 8a is slower than addition to 4- trifluoromethyl-trans-β-nitrostyrene 8b. However, the mechanism does not appear to be effected as the overall order of the reaction does not change. The addition of N-methylindole 9b to unsubstituted trans-β-nitrostyrene 8a catalyzed by 3a has a reaction profile similar to the addition to 4-trifluoromethyl-trans-β-nitrostyrene 8b catalyzed by triphenylsilanol 4. Procedure: A stock solution was made with trans-β-nitrostyrene (8a) (3.2 M) and trimethylphenylsilane (.5 M) in CD 2 Cl 2. The catalyst (.14 mmol) was dissolved in.44 ml of the stock solution and transferred to an oven-dried and argon-purged NMR tube. An initial 1 H NMR scan was taken before the addition of N-methylindole (9b) (.26 ml, 1.5 equiv) and then the reaction was monitored using 1 H NMR spectroscopy by taking a spectrum every 3 6 minutes. S43

44 Table S43. 1 H NMR data Time (min) [8a] M [1c] M ln[8a] S44

45 Figure S35. Comparison of 19 F NMR and 1 H NMR data for the indole addition to trans-βnitrostyrene 8a catalyzed by tetraphenyldisiloxanediol 3a (Table S39) to the addition to 4- trifluoromethyl-trans-β-nitrostyrene 8b (Table S6) addition to 4-trifluoromethyl-trans-βnitrostyrene 8b catalyzed by triphenylsilanol 4 (Table S1). S45

46 VI. Michael Reaction Competition Experiments To gain mechanistic insight into the Michael addition reaction catalyzed by 1,3-disiloxanediols, competition reactions were performed with two nucleophiles present according to the following procedure: Catalyst 3a (.12 g,.3 mmol,.1 equiv) and 4-trifluoromethyl-trans-βnitrostyrene 8b (.65 g,.3 mmol, 1. equiv) were added to a flame-dried, Ar-purged vial and dissolved in DCM (.2 ml). Two nucleophiles (.45 mmol) were then added to the vials and the reaction was allowed to stir for 24 h at which time yields were determined by 19 F NMR using fluorobenzene as an internal standard. When both N-methylindole and 3-methoxy-N,Ndimethylaniline were used as nucleophiles (as seen in Figure S36), addition to nitrostyrene was observed in comparable yields (35 and 39%). These different nucleophiles have different electronic properties resulting in different yields for experiments A and B; however, when they compete in the same flask, a product ratio of roughly 1:1 was observed, indicating that the reaction is not dependent on the nucleophile. A. N NO 2 3a(1 mol %) F 3 C N DCM NO 2 F 3 C 76% B. NMe 2 NO 2 O 3a(1 mol %) MeO F 3 C NMe 2 DCM NO 2 F 3 C 44% C. NMe 2 F 3 C NO 2 O NMe 2 N 3a(1 mol %) DCM MeO NO 2 N NO 2 F 3 C F 3 C 35% 39% Figure S36. A. Addition of N-methylindole to 4-trifluoromethyl-trans-β-nitrostyrene (8b); B. Addition of 3-methoxy-N,N-dimethylaniline to 4-trifluoromethyl-trans-β-nitrostyrene (8b); C. Competition Experiments with N-methylindole and 3-methoxy-N,N-dimethylaniline. Competition experiment (C) is reported as an average of two trials. S46

47 VII. Derivation of Rate Law Me N Catalyst Resting State Ph Ph Ph O Si Si Ph OH 3a OH Ar 8b NO 2 Ar 1b 9b NO 2 Me N k2 Ph Ph Si O O Ph Si Ph O H H 13 N O δ Figure S37. Proposed mechanism for Michael addition reaction δ O Ar k1 k-1 Turnover-limiting Step Given our proposed catalytic cycle the steady state rate equation can be written:![!"#]!" =!!!!!"!" [!"]!!!"!!!!!!! [!"] (Equation S5) We propose that the initial binding of the catalyst is very weak (producing only a small steady state concentration of 13), however once activated nucleophilic capture is very rapid thus k -1 and k 2 are very large relative to k 1. We can thus simplify the equation to:![!"#]!" =!!!!!"!" [!"]!!!!!! [!"] Again, provided k 2 is larger than k -1 we can further simplify to:![!"#]!" (Equation S6) =!!!" [!"] (Equation S7) We believe that under synthetically relevant conditions this model explain the observed behavior. The relatively weak binding of the free disiloxanediol to the nitro group also accounts for the lack of any product deactivation and the very good agreement with our same excess experiments. In addition, depending on the relative values of k -1 and k 2, there will exists some concentration ration of 8b and 9b such that this approximation begins to fail and a small positive order in 9b may be observed. S47

48 VIII. Disiloxanediol Binding Studies using 1 H NMR spectroscopy General Procedure Two stock solutions were each made by dissolving.6 mmol of a disiloxanediol in 6. ml of deuterated solvent [C 6 D 6 ]. Nitrostyrene (.3 mmol, 5. equiv) was added to only one of the stock solutions. Then different volumes of each stock solution were mixed to make.6 ml of solution with the desired equivalents of Lewis base. The 1 H NMR spectrum of each solution was recorded after eight scans at room temperature. Figure S38. NMR binding study of disiloxanediol 3a (1 mm in C 6 D 6 ) in the presence of transβ-nitrostyrene. Silanol δ =.5 ppm in the presence of 5. equiv of trans-β-nitrostyrene. It can not be ruled out that the small chemical shift change is from small concentration deviations as nitrostyrene is titrated in. S48

49 Figure S39. NMR binding study of disiloxanediol 3a (4 mm in C 6 D 6 ) in the presence of trans-β-nitrostyrene. Silanol δ =.1 ppm in the presence of 5. equiv of trans-β-nitrostyrene. Shifting is also observed in nitrostyrene peaks providing further evidence for the binding interaction (δ =.16 ppm). S49

50 Figure S4. NMR binding study of disiloxanediol 3d (2 mm in C 6 D 6 ) in the presence of trans-β-nitrostyrene. Silanol δ =.35 and.44 ppm in the presence of 5. equiv of trans-βnitrostyrene. K a (SiOH A ) = 158 ± 14 M -1 and K a (SiOH B ) = 94 ± 5 M -1. S5

51 Evaluation of 1,3-disiloxanediol and Indole Binding In order to determine if 1,3-disiloxanediols could be binding to Indole a binding experiment was performed using disiloxanediol 3a and indole 9a. Figure S41. NMR binding study of disiloxanediol 3a (1 mm in CDCl 3 ) in the presence of indole 9a. Small changes in Indole N-H peak is observed and can be attributed to concertation effects as observed in the differences between indole spectra of 1. M and.1 M. S51

52 IX. X-Ray Crystallographic Structure and Information Crystals for 3b and 3d were grown from slow evaporation of toluene. IXa. X-Ray analysis of 3b: Figure S42. ORTEP Drawing of 3b with Thermal Ellipsoids at 5% Probability Levels. Figure S43. X-Ray structure of 3b showing linear hydrogen-bonding network. One dimensional linear hydrogen bonds are connected through pi stacking of naphthyl substituents. S52

53 Table SI44. Crystal data for 3b. Identification code JF269FP1 Empirical formula C4 H3 O3 Si2 Formula weight Temperature 9(2) K Wavelength.7173 Å Crystal system Triclinic Space group P1 Unit cell dimensions a = (6) Å α= (11). b = 9.234(8) Å β= (11). c = (1) Å γ = (12). Volume (11) Å 3 Z 1 Density (calculated) 1.37 Mg/m 3 Absorption coefficient.16 mm F() 322 Crystal size.266 x.197 x.98 mm 3 Crystal color and habit Colorless Block Diffractometer Bruker APEX-II CCD Theta range for data collection to Index ranges -1<=h<=1, -13<=k<=13, -16<=l<=16 Reflections collected Independent reflections 935 [R(int) =.114] Observed reflections (I > 2sigma(I)) 911 Completeness to theta = % Absorption correction Semi-empirical from equivalents Max. and min. transmission.9766 and.912 Solution method SHELXT (Sheldrick, 214) Refinement method SHELXL-216/6 (Sheldrick, 216) Full-matrix least-squares on F 2 Data / restraints / parameters 935 / 5 / 528 Goodness-of-fit on F Final R indices [I>2sigma(I)] R1 =.374, wr2 =.112 R indices (all data) R1 =.379, wr2 =.118 Absolute structure parameter.49(1) Extinction coefficient.19(4) Largest diff. peak and hole.462 and -.39 e.å -3 S53

54 IXb. X-Ray analysis of 3d: Figure S44. ORTEP Drawing of 3d with Thermal Ellipsoids at 5% Probability Levels. Figure S45. X-Ray structure of 3d showing hydrogen-bonding network. The 1,3-disiloxanediol dimers are connected through hydrogen-fluorine interactions S54

55 Table S45. Crystal data for 3d. Identification code JF268FMI Empirical formula C26 H28 F2 O3 Si2 Formula weight Temperature 1(2) K Wavelength.7173 Å Crystal system Triclinic Space group P-1 Unit cell dimensions a = 8.51(8) Å a= 86.11(3). b = (1) Å b= 72.9(3). c = (11) Å g = (3). Volume (18) Å 3 Z 2 Density (calculated) 1.36 Mg/m 3 Absorption coefficient.193 mm F() 58 Crystal size.719 x.425 x.162 mm 3 Theta range for data collection to Index ranges -12<=h<=12, -16<=k<=16, -18<=l<=18 Reflections collected Independent reflections 723 [R(int) =.93] Completeness to theta = % Absorption correction Semi-empirical from equivalents Max. and min. transmission.9376 and.927 Refinement method Full-matrix least-squares on F 2 Data / restraints / parameters 723 / 3 / 415 Goodness-of-fit on F Final R indices [I>2sigma(I)] R1 =.287, wr2 =.812 R indices (all data) R1 =.3, wr2 =.82 Extinction coefficient.148(17) Largest diff. peak and hole.494and e.å -3 S55

56 VI. 1 H and 13 C NMR spectra CDCl 3, 6 MHz, 1 H NMR F F Si H H S1 S56

57 CDCl 3, 15 MHz, 13 C NMR F F Si H H S1 S57

58 CD 2 Cl 2, 6 MHz, 1 H NMR HO OH Si F 2c F S58

59 CD 2 Cl 2, 15 MHz, 13 C NMR HO OH Si F 2c F S59

60 C 6 D 6 (4 mm), 6 MHz, 1 H NMR Ph Ph O Ph Si Si Ph OH Me 5 S6

61 CDCl 3, 15 MHz, 13 C NMR Ph Ph O Ph Si Si Ph OH Me 5 S61

62 CDCl 3, 6 MHz, 1 H NMR Ph Ph HO Si O Ph Si Ph O 6 SiMe 3 S62

63 CDCl 3, 15 MHz, 13 C NMR Ph Ph HO Si O Ph Si Ph O 6 SiMe 3 S63

64 CDCl 3, 4 MHz, 1 H NMR NH NO 2 1a S64