SUPPORTING INFORMATION

Transcription

1 S1 SUPPORTING INFORMATION Cyclization of 1,6-enynes catalyzed by gold nanoparticles supported on TiO 2 : Significant changes in selectivity and mechanism, as compared to homogeneous Au-catalysis Charis Gryparis, Christina Efe, Christos Raptis, Ioannis N. Lykakis, and Manolis Stratakis* Department of Chemistry, University of Crete, Voutes, Iraklion, Greece. stratakis@chemistry.uoc.gr Pages S2-S8 Pages S9-S37 Page S38 Table of contents Experimental section NMR spectra of key compounds and reactions Additional mechanistic discussion

2 S2 Experimental Section Synthesis of 1,6-enynes 1,6-Enynes 1-11 were prepared in overall yields of 70-88% by double alkylation of dimethyl malonate with commercially or readily available alkenyl and propargyl bromides, as described in the literature. Synthesis of D-labelled 1,6-enynes 2-d and 5-d Enynes 2-d 1 and 5-d 1 were prepared in >90% yield by the reaction of 1 equivalent of n- BuLi with 2 and 5 respectively (THF, -78 o C, 1 h), followed by quench with D 2 O. The isotope incorporation on the terminal acetylenic carbon atoms was >97%. Synthesis of D-labelled 1,6-enynes 1-d, 1 -d and 6-d Enyne 1-d (95% deuterium incorporation) was prepared by sequential alkylation of dimethyl malonate with propargyl bromide and 2-D-allyl mesylate. The labile mesylate was synthesized from the corresponding deuterated alcohol, which in turn was prepared by

3 S3 the addition of LiAlD 4 (20% molar excess) to propargyl alcohol (diethyl ether, 24 h, 35 o C), followed by quench with H 2 O, as described in the literature. 2 The volatile allyl alcohol-2-d was purified by distillation (44% isolated yield). 1 H NMR of 1-d (300 MHz, CDCl 3 ): 5.17 (br s, 1H), 5.13 (br s, 1H), 3.74 (s, 6H), 2.80 (br s, 2H), 2.79 (d, J = 2.5 Hz, 2H), 2 (t, J = 2.5 Hz, 1H). 13 C NMR of 1-d (75 MHz, CDCl 3 ): 170.1, 131.3, 119.8, 78.7, 71.4, 56.8, 52.7, 36.4, Following the same procedure, yet, reducing propargyl alcohol with LiAlH 4 followed by quench with D 2 O, (Z)-allyl alcohol-3-d was stereoselectively prepared and used for the preparation of 1 -d and 6-d by sequential alkylation of dimethyl malonate. The deuterium content in (Z)-allyl alcohol-3-d was 60%, thus although enynes 1 -d and 6-d are stereochemically pure in terms of their H/D position on the terminal olefinic carbon atoms, they are contaminated with 40% with fully protonated 1 and 6, respectively. 1 H NMR of 1 -d (300 MHz, CDCl 3 ): 5.61 (m, 1H), 5.12 (d, J = Hz, 1H), 3.74 (s, 6H), 2.81 (d, J = 7.5 Hz, 2H), 2.80 (d, J = 2.5 Hz, 2H), 2 (t, J = 2.5 Hz, 1H). 13 C NMR of 1 - d (75 MHz, CDCl 3 ): 170.1, 131.5, (t, J C-D = 23.5 Hz), 78.7, 71.4, 56.8, 52.8, 36.4, H NMR of 6-d (300 MHz, CDCl 3 ): 5.61 (m, 1H), 9 (d, J = Hz, 1H), 3.72 (s, 6H), 2.78 (d, J = 7.5 Hz, 2H), 2.73 (q, J = 2.5 Hz, 2H), 1.75 (t, J = 2.5 Hz, 3H). 13 C NMR of 6-d (75 MHz, CDCl 3 ): 170.5, 131.9, (t, J C-D = 2 Hz), 78.9, 73.2, 57.2, 52.6, 36.5, 2, 3.4. General procedure for the Au/TiO 2 -catalyzed cyclization To a vial containing 0.3 mmol of the 1,6-enyne and 0.5 ml 1,2-dichloroethane were added 70 mg Au/TiO 2 (~037 mmol, 1 wt% in Au). The reaction was heated to 70 o C for a certain period of time (see Schemes 1 and 2) until the enyne had been consumed (GC-MS, TLC). Then the slurry was filtered with the aid of 2 ml dichloromethane through a short pad of silica gel and the filtrate was evaporated under vacuum. Chromatographic purification is followed if necessary.

4 S4 Spectroscopic data of cyclization products Dimethyl 3-vinylcyclopent-3-ene-1,1-dicarboxylate (1a) 1 1 H NMR: (300 MHz, CDCl 3 ): 6.47 (dd, J 1 = 10.5 Hz, J 2 = 1 Hz, 1H), 5.57 (br s, 1H), 9 (br d, J = 10.5 Hz, 1H), 8 (br d, J = 1 Hz, 1H), 3.74 (s, 6H), 3.13 (br s, 2H), 3.10 (br s, 2H). 13 C NMR: (75 MHz, CDCl 3 ): 172.4, 14, 132.3, 126.8, 115.1, 58.6, 52.9, 40.8, Dimethyl 3-methyl-4-vinylcyclopent-3-ene-1,1-dicarboxylate (2a) 1 1 H NMR: (300 MHz, CDCl 3 ): 6.55 (dd, J 1 = 1 Hz, J 2 = 1 Hz, 1H), 6 (br d, J = 1 Hz, 1H), 4 (br d, J = 1 Hz, 1H), 3.73 (s, 6H), 3.14 (br s, 2H), 6 (br s, 2H), 1.75 (br s, 3H). 13 C NMR (75 MHz, CDCl 3 ): 172.6, 134.7, 131.2, 13, 113.7, 56.9, 52.8, 46.4, 40.5, (E and Z)-Dimethyl 3-(prop-1-en-1-yl)cyclopent-3-ene-1,1-dicarboxylate (3a) 1 (E)-Isomer: 1 H NMR (300 MHz, CDCl 3 ): 6.18 (d, J = 15.5 Hz, 1H), 5.56 (dq, J 1 = 15.5 Hz, J 2 = 6.5 Hz, 1H), 5.40 (m, 1H), 3.73 (s, 6H), 9 (s, 2H), 6 (br s, 2H), 1.76 (d, J = 6.5 Hz, 3H). 13 C NMR (75 MHz, CDCl 3 ): 172.6, 139.6, 127.2, 12, 123.5, 58.8, 52.8, 40.7, 39.8, (Z)-Isomer: 1 H NMR (300 MHz, CDCl 3 ): 5.91 (d, J = 1 Hz, 1H), 5.50 (dq, J 1 = 1 Hz, J 2 = Hz, 1H), 5.49 (m, 1H), 3.74 (s, 6H), 3.26 (br s, 2H), 6 (s, 2H), 1.82 (d, J = Hz, 3H). 13 C NMR (75 MHz, CDCl 3 ): 172.5, 138.6, 126.6, 126.5, 12, 59.4, 52.9, 43.1, 40.2, 1. (E and Z)-Dimethyl 5-ethylidenecyclohex-3-ene-1,1-dicarboxylate (3b) 3 (Z)-Isomer: 1 H NMR (300 MHz, CDCl 3 ): 6.42 (d, J = Hz, 1H), 5.76 (m, 1H), 5.34 (q, J = Hz, 1H), 3.70 (s, 6H), 2.79 (s, 2H), 2.70 (br s, 2H), 1.67 (d, J = Hz, 3H). 13 C NMR (75 MHz, CDCl 3 ): 171.5, 129.7, 125.2, 123.7, 122.9, 54.1, 52.6, 37.2, 31.7, 12.8.

5 S5 (E)-Isomer: 1 H NMR (300 MHz, CDCl 3 ): 4 (d, J = 9.5 Hz, 1H), 5.60 (m, 1H), 5.41 (q, J = Hz, 1H), 3.71 (s, 6H), 2.87 (s, 2H), 2.71 (br s, 2H), 1.74 (d, J = Hz, 3H). Dimethyl 3-methylene-4-(prop-1-en-2-yl)cyclopentane-1,1-dicarboxylate (5a) 1 1 H NMR: (300 MHz, CDCl 3 ): 1 (br s, 1H), 4.83 (br s, 2H), 4.79 (br s, 1H), 3.74 (s, 3H), 3.72 (s, 3H), 3.27 (m, 1H), 7 (d, J = 1 Hz, 1H), 2.92 (br d, J = 1 Hz, 1H), 2.51 (dd, J 1 = 1 Hz, J 2 = 7.5 Hz, 1H), 2.12 (dd, J 1 = 1 Hz, J 2 = 11.5 Hz, 1H), 1.64 (br s, 3H). 13 C NMR: (75 MHz, CDCl 3 ): 172.1, 17, 149.2, 144.6, 113.4, 108.1, 58.7, 52.8, 52.7, 5, 40.8, 38.6, Dimethyl 5-(propan-2-ylidene)cyclohex-3-ene-1,1-dicarboxylate (5c) 3 1 H NMR: (300 MHz, CDCl 3 ): 6.43 (br d, J =9.5 Hz, 1H), 5.61 (td, J 1 = 9.5 Hz, J 2 =4.5 Hz, 1H), 3.69 (s, 6H), 2.83 (s, 2H), 2.86 (br s, 2H), 1.77 (br s, 6H). 13 C NMR: (75 MHz, CDCl 3 ): 171.8, 129.7, 125.6, 123.7, 122.4, 54.1, 52.6, 3, 3, 20.4, 2. Dimethyl 5-(prop-1-en-2-yl)cyclohex-3-ene-1,1-dicarboxylate (5d) 1 H NMR: (300 MHz, CDCl 3 ): 5.74 (m, 1H), 5.57 (br d, J = 9.5 Hz, 1H), 4.77 (br s, 1H), 4.75 (br s, 1H), 3.74 (s, 3H), 3.70 (s, 3H), 2.84 (m, 1H), 2.73 (br d, J = 1 Hz, 1H), (m, 2H), 1.88 (dd, J 1 = 13.5 Hz, J 2 = 10.5 Hz, 1H), 1.72 (br s, 3H). 13 C NMR: (75 MHz, CDCl 3 ): 172.3, 171.4, 147.3, 129.4, 124.4, 111.1, 53.3, 52.6, 52.6, 40.7, 32.8, 30.4, HRMS: calcd for C 13 H 18 O 4 +H, ; found (4E,4'E)-Tetramethyl 4,4'-(ethane-1,2-diylidene)bis(3-(prop-1-en-2-yl)cyclopentane- 1,1-dicarboxylate) (5e) 4

6 S6 1 H NMR: (300 MHz, CDCl 3 ): 5.81 (br s, 2H), 4.87 (br s, 2H), 4.85 (br s, 2H), 3.74 (s, 6H), 3.73, (s, 6H), 3.34 (m, 2H), 3.17 (d, J = 1 Hz, 2H), 2.88 (br d, J = 1 Hz, 2H), 2.49 (dd, J 1 = 1 Hz, J 2 = 7.5 Hz, 2H), 2.11 (dd, J 1 = 1 Hz, J 2 = 1 Hz, 2H), 1.62 (br s, 6H). 13 C NMR: (75 MHz, CDCl 3 ): and 17 (meso+dl), and (meso+dl), and (meso+dl), and (meso+dl), (meso+dl), 58.8 and 58.8 (meso+dl), 52.9 and 52.8 (meso+dl), 51.8 (meso+dl), 38.4 and 38.3 (meso+dl), 37.7 and 37.7 (meso+dl), 1 and 1 (meso+dl). HRMS: calcd for C 26 H 34 O 8 +H, ; found Dimethyl 3-(prop-1-en-2-yl)cyclopent-3-ene-1,1-dicarboxylate (6a) 1 1 H NMR: (300 MHz, CDCl 3 ): 5.59 (br s, 1H), 4.93 (br s, 1H), 4.89 (br s, 1H), 3.73 (s, 6H), 3.17 (br s, 2H), 3.12 (s, 2H), 1.89 (br s, 3H). 13 C NMR: (75 MHz, CDCl 3 ): 172.5, 141.4, 138.8, 123.7, 113.3, 58.8, 52.8, 41.1, 40.6, Dimethyl 3-methyl-4-(prop-1-en-2-yl)cyclopent-3-ene-1,1-dicarboxylate (7a) 5 1 H NMR: (300 MHz, CDCl 3 ): 4.94 (br s, 1H), 4.80 (br s, 1H), 3.73 (s, 6H), 3.14 (s, 2H), 5 (s, 2H), 1.90 (br s, 3H), 1.79 (br s, 3H). 13 C NMR: (75 MHz, CDCl 3 ): 172.7, 140.3, 13, 131.4, 114.1, 56.7, 52.8, 47.2, 43.6, 22.5, Dimethyl 3-isopropyl-4-vinylidenecyclopentane-1,1-dicarboxylate (8a) 1 H NMR (300 MHz, CDCl 3 ): 4.76 (dd, J 1 = Hz, J 2 = Hz, 1H), 4.73 (dd, J 1 = Hz, J 2 = Hz, 1H), 3.74 (s, 3H), 3.72 (s, 3H), 4 (br d, J = 16.5 Hz, 1H), 2.91 (br td, J 1 = 16.5 Hz, J 2 = Hz, 1H), 2.67 (m, 1H), 2.41 (ddd, J 1 = 1 Hz, J 2 = Hz, J 3 = Hz, 1H), 1.86 (dd, J 1 = 1 Hz, J 2 = 1 Hz, 1H), 0.95 (d, J = Hz, 3H), 0.86 (d, J = Hz, 3H). 13 C NMR (75 MHz, CDCl 3 ): 202.7, 17, 171.9, 102.8, 77.6, 59.1, 52.8, 52.8, 47.1, 38.7, 35.8, 30.2, 20.9, HRMS: calcd for C 14 H 20 O 4 +H, ; found

7 S7 Dimethyl 4-methyl-5-(prop-1-en-2-yl)cyclohex-3-ene-1,1-dicarboxylate (8b) 1 H NMR (300 MHz, CDCl 3 ): 5.50 (m, 1H), 4.83 (br s, 1H), 4.80 (br s, 1H), 3.73 (s, 3H), 3.69 (s, 3H), 2.86 (m, 1H), 2.66 (br d, J = 1 Hz, 1H), 2.45 (br d, J = 1 Hz, 1H), 2.33 (dd, J 1 = 1 Hz, J 2 = 6.5 Hz, 1H), 1.96 (dd, J 1 = 1 Hz, J 2 = Hz, 1H), 1.60 (br s, 3H), 1.53 (br s, 3H). 13 C NMR: (75 MHz, CDCl 3 ): 172.5, 171.6, 145.8, 134.5, 120.5, 113.7, 53.2, 52.6, 52.5, 46.1, 31.6, 30.7, 21.3, HRMS: calcd for C 14 H 20 O 4 +H, ; found Dimethyl 3-(1-phenylvinyl)cyclopent-3-ene-1,1-dicarboxylate (9a) 6 1 H NMR (300 MHz, CDCl 3 ): (m, 5H), 5.44 (br s, 1H), 5.19 (br s, 1H), 5.13 (br s, 1H), 3.77 (s, 6H), 3.30 (br s, 1H), 3.13 (br s, 1H). 13 C NMR (75 MHz, CDCl 3 ): 172.5, 145.3, 141.3, 140.5, 128.4, 127.9, 127.4, 123.3, 114.8, 58.8, 52.9, 41.3, Dimethyl 4,4-dimethyl-3a,4-dihydro-1H-cyclopenta[b]naphthalene-2,2(3H)-dicarboxylate (11a) 7 1 H NMR (300 MHz, CDCl 3 ): 7.27 (m, 2H), 7.14 (m, 2H), 1 (m, 1H), 6.35 (br s, 1H), 3.77 (s, 3H), 3.72 (s, 3H), 3.30 (d, J = 18.5 Hz, 1H), 2.98 (br d, J = 18.5 Hz, 1H), 2.69 (m, 1H), 2.61 (m, 1H), 2.14 (t, J = 1 Hz, 1H), 1.42 (s, 3H), 0.92 (s, 3H). 13 C NMR (75 MHz, CDCl 3 ): 172.1, 171.9, 14, 142.9, 133.9, 126.9, 126.2, 126.2, 123.4, 119.3, 58.9, 52.9, 52.8, 48.4, 39.2, 36.6, 34.8, 25.6, 2. References 1. Nieto-Oberhuber, C.; Paz Munoz, M.; Lopez, S.; Jimenez-Nunez, E.; Nevado, C.; Herrero-Gomez, E.; Raducan, M.; Echavarren, A. M. Chem. Eur. J. 2006, 12, Minsek, D. W.; Chen, P. J. Phys. Chem. 1993, 97, Faller, J. W.; Fontaine, P. P. J. Organomet. Chem. 2006, 691, Porcel, S.; Echavarren, A. M. Angew. Chem. Int. Ed. 2007, 46, 2672.

8 S8 5. Kitamura, T.; Sato, Y.; Mori, M. Adv. Synth. Catal. 2002, 344, Ota, K.; Chatani, N. Chem. Commun. 2008, Nieto-Oberhuber, C.; Perez-Galan, P.; Herrero-Gomez, E.; Lauterbach, T.; Rodriguez, C.; Lopez, S.; Bour, C.; Rosellon, A.; Cardenas, D. J.; Echavarren, A. M. J. Am. Chem. Soc. 2008, 130, 269.

9 S9 1 H and 13 C NMR spectra

10 S

11 S ppm

12 S

13 S

14 S14 * = hexane

15 S

16 S

17 S

18 S18 * = hexane

19 S19 * = hexane; * = H 2 O * = hexane

20 S

21 S21 * = hexane

22 S

23 S

24 S24 * = hexane * = hexane

25 S

26 S

27 S

28 S28

29 S

30 S

31 S

32 S ppm ppm ppm

33 S

34 S ppm ppm ppm

35 S35 The irradiation of the H a proton of 5a resonating at 1 ppm, results to a signal enhancement of the geminal H b (19%) at 4.79 ppm, and to H c (~1.5%) at 7 ppm. The irradiation of the H c proton of 5a resonating at 7 ppm, results to a signal enhancement of H a (~1.5%) at 1 ppm, and to geminal H d (15.5%) at 2.92 ppm.

36 S

37 S

38 S38 Additional Mechanistic Discussion The possibility of participation of a pseudo cationic intermediate VII formed from cyclobutyl gold carbene I via TS 1 (references 2a-b) can be ruled out. This intermediate cannot account to the stereoselective cyclization of 1'-d and 6-d as the existence of an unstable primary carbocation is required. Additionally, intermediate III (if formed), should lead to the non stereoselective H/D disposition in products 1'a-d and 6a-d.