synthesis of chiral (tetrazolyl)methyl-containing ... · pdf filesilicon-induced...

SI-1

Electronic Supplementary Information

Synthesis of chiral (tetrazolyl)methyl-containing acrylates via

silicon-induced organocatalytic kinetic resolution of

Morita–Baylis–Hillman fluorides

Takayuki Nishimine,a Hiromi Taira,a Satoru Mori,a Okiya Matsubara,a Etsuko

Tokunaga,a Hidehiko Akiyama,b Vadim A. Soloshonokc and Norio Shibataa*

aDepartment of Nanopharmaceutical Sciences & Department of Frontier Materials, Nagoya Institute of

Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan

bFaculty of Medical Technology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho,

Toyoake, 470-1192, Japan

cDepartment of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU,

20018 San Sebastián, Spain; IKERBASQUE, Basque Foundation for Science, Alameda Urquijo 36-5,

Plaza Bizkaia, 48011 Bilbao, Spain

Table of Contents

1. General Methods………………………………………………..………………………………….…SI-2

2. Table S1. Optimization of the chiral catalyst……………………………………………………. ...SI-3

3. Figure S1, Apoptosis-induction in U937 cells by rac-tetrazole 4……………………………………SI-4

4. Figure S2. Plots and histograms after 24h treatment with racemic-4……..…………...SI-5

5. General procedure for the preparation of Morita-Baylis-Hillman (MBH) fluorides 2 and

tetrazole-acrylates 3 .………………………………………………. .…………………………………SI-6

6. HPLC Spectrum of compounds 2 and 3…………………………………………………….……….SI-15

7. 1H, 13C, 19F NMR Spectra of tetrazole-acrylates 3…………………………………….…….….SI-26

Electronic Supplementary Material (ESI) for ChemComm.This journal is © The Royal Society of Chemistry 2016

SI-2

General Methods:

All reactions were performed in oven-dried glassware under a positive pressure of nitrogen. Solvents

were transferred via syringe and were introduced into the reaction vessels through a rubber septum. All

reactions were monitored by thin-layer chromatography (TLC) carried out on 0.25 mm Merck silica gel

(60-F254). The TLC plates were visualized with UV light and 7% phosphomolybdic acid in ethanol/heat

or KMnO4 in water/heat. Column chromatography was carried out on a column packed with silica gel

60N spherical neutral size 63-210 μm. The 1H-NMR (300 MHz), 19F-NMR (282 MHz) and 13C-NMR

(150.9 MHz) spectra for solution in CDCl3, were recorded on a Buruker Advance 600 and a Varian

Mercury 300. Chemical shifts (δ) are expressed in ppm downfield from internal TMS (tetramethylsilane),

C6H5CF3 or CHCl3. HPLC analyses were performed on a JASCO U-2080 Plus using 4.6 x 250 mm

CHIRALPAK IA-3, IB and IC columns. Mass spectra were recorded on a SHIMAZU LCMS-2010EV or

SHIMAZU LCMS-2020EV (ESI-MS). Optical rotations were measured on a HORIBA SEPA-300.

Infrared spectra were recorded on a JASCO FT/IR-4100 spectrometer.

SI-3

Table S1. Optimization of the chiral catalyst.a,b,c

(DHQD)2PYR45%, 68% ee

N

MeO

OH

N

N N

OH

N

N

OMe

Et Et

N

MeO

O

N

Et

H

N N

O

N

OMe

H

N

Et

(DHQ)2PYR34%, –51% ee

N

MeO

OH

N

O O

OH

N

N

OMe

(DHQD)2AQN27%, 40% ee

Et Et

N

MeO

O

N

Et

O O

O

N

OMe

N

Et

HH

N

MeO

OH

N NN

OH

N

N

OMe

(DHQD)2PHAL51%, 92% ee

Et Et

N

MeO

O

N

Et

H

NN

O

N

OMe

N

Et

H

(DHQ)2AQN36%, –25% ee

(DHQ)2PHAL53%, –63% ee

1,4-dioxane, RT, 24 h

MS 4Å

Catalyst (10 mol%)

F

MeO2CPh

PhMeO2C

(S)-4a

N

N

NN

Ph

SiMe3

NN

NN

Ph1a 3a

+ MeO2CPh

+

(R)-3a

F

(1.0 equiv.)

aThe reactions of 1a with 3a (1.0 equiv.) were carried out in the presence of catalyst (10 mol%) and MS 4Å in dry 1,4-dioxane (0.1 M) at ambient temperature under nitrogen atmosphere, unless otherwise noted. bIsolated yield. cDetermined by HPLC analysis.

SI-4

Figure S1. Apoptosis-induction in U937 cells by rac-tetrazole 3.

To test the medicinal potential of this structurally new type of tetrazole–containing derivatives, we

conducted a preliminary biological evaluation of compounds 4 against U937 cells (human monocytic

leukemia cell line; RCB0435) using an annexin V assay. To investigate the fundamental biological

activity, racemic 4 was used for evaluation. To this end, six tetrazoles of 4a, 4e, 4h, 4i, 4j and 4k were

randomly selected for biological assay in vitro on the standard annexin apoptosis by flow cytometry

analysis (Figure SI, at a concentration of 20 μM, after 24h). Quite remarkably, nearly all tetrazoles 4

understudy, induced spontaneous apoptosis of U937 cells. In particular, tetrazole 4e was found to be the

most potent, while derivative 4a did not show the activity at this concentration. Additional data of plots

and histograms after 24h treatment with 4 at a concentration of 20 μM are shown in Figure S1 in

supporting information.

SI-5

Figure S2. Plots and histograms after 24h treatment with racemic-4 at a concentration of 20 μM.

There was a time-dependent increase in the annexin V-positive rate in all treated cells. Among

the observations, we can point out that, 4e was clearly more active versus to 4a. Second, others 4 except 4a also showed activity registered at 20 μM level.

SI-6

Experimental Section:

General procedure for the Morita-Baylis-Hillman (MBH) fluorides 2.

The syntheses were carried out by a literature procedure.[1,2] To a solution of MBH allylic alchol (1.0

equiv.) in dry CH2Cl2 (0.33 M), diethylaminosulfur trifluoride (DAST; 1.2 equiv.) was added with stirring

at –78 ºC under nitrogen atmosphere. After stirring for 2 h, the reaction was quenched with saturated

NaHCO3 and the mixture was brought to ambient temperature. The organic layer was taken and the

aqueous layer was extracted with CH2Cl2. The combined organic layers were washed with brine, dried

over anhydrous Na2SO4, filtered and the solvent was removed under reduced pressure. The residue was

purified by silica gel column chromatography (n-Hexane/Et2O) to give the MBH-fluoride 3. The obtained

characterizing data matched with literature information.

General procedure for the tetrazole-acrylates 3.

To a solution of (DHQD)2PHAL (0.01 mmol; 7.8 mg), MS 4Å (10.0 mg) and

2-[(trimethylsilyl)methyl]-2H-tetrazole 1 (0.1 mmol) in 1.0 mL dry 1,4-dioxane (0.1 M), MBH-fluoride 3

(0.1 mmol) was added with stirring at ambient temperature under nitrogen atmosphere. After stirring for

24–120 h, the reaction mixture was separated by short silica gel chromatography (Et2O), and the fractions

containing the product were concentrated in vacuo. The residue was further purified by silica gel column

chromatography (n-Hexane/EtOAc) to give tetrazole-acrylate (S)-4 and recovered MBH-fluoride (R)-3.

1 T. Nishimine, K. Fukushi, N. Shibata, H. Taira, E. Tokunaga, A. Yamano, M. Shiro, N. Shibata, Angew. Chem. 2014, 126, 527−530; Angew. Chem. Int. Ed. 2014, 53, 517−520. 2 T. Nishimine, H. Taira, E. Tokunaga, M. Shiro, N. Shibata, Angew. Chem. 2016, 128, 367−371; Angew. Chem. Int. Ed. 2016, 55, 359−363.

SI-7

(S)-Methyl 2-methylene-3-phenyl-4-(5-phenyl-2H-tetrazol-2-yl)butanoate (4a)

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3a (0.1 mmol; 19.4 mg),

(DHQD)2PHAL (0.01 mmol; 7.8 mg) and MS 4Å (10.0 mg) in 1.0 mL dry 1,4-dioxane (0.1 M) at ambient

temperature for 48 h afforded the crude mixture. The residue was purified by silica gel column

chromatography (n-Hexane/EtOAc) to give (S)-4a (43%, 92% ee) as a white solid and recovered (R)-3a

(31%, 75% ee) as a colorless oil.

1H NMR (CDCl3, 300 MHz): δ 3.69 (s, 3H), 4.87 (dd, J = 8.1, 8.1 Hz, 1H), 5.02 (dd, J = 7.8, 13.2 Hz,

1H), 5.23 (dd, J = 8.7, 13.2 Hz, 1H), 5.84 (s, 1H), 6.40 (s, 1H), 7.25–7.34 (m, 5H), 7.46–7.49 (m, 3H),

8.10–8.13 (m, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 46.7, 52.1, 55.5, 126.6, 126.8, 127.3, 127.7, 127.9,

128.8, 128.8, 130.3, 137.8, 139.1, 165.0, 166.2; IR (KBr): 3420, 3114, 2959, 2924, 2854, 1717, 1631,

1529, 1450, 1270, 1153, 708 cm-1; Mp = 106.9–107.6 ºC; MS (ESI): m/z = 357 (M+Na+); HRMS (ESI)

calcd. for C19H18N4NaO2: (M+Na+); 357.1327, found: 357.1335;

The ee of the product was determined by HPLC using an IB column (n-Hexane/i-PrOH = 95/5, flow late

1.0 mL/min, λ = 254 nm, τmaj = 21.0 min, τmin = 23.9 min); [α]D25= +128.1 (c = 0.35, CHCl3), 92% ee.

(S)-Methyl 4-(5-(2-bromophenyl)-2H-tetrazol-2-yl)-2-methylene-3-phenylbutanoate (4b)

According to the general procedure, a reaction of 1b (0.1 mmol; 31.1 mg), 3a (0.1 mmol; 19.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4b (43%, 82% ee) as a pale yellow oil and recovered

(R)-3a (21%, 95% ee) as a colorless oil.


1H), 5.28 (dd, J = 8.7, 13.5 Hz, 1H), 5.84 (s, 1H), 6.41 (s, 1H), 7.26–7.35 (m, 6H), 7.42 (dd, J = 7.5, 7.5

Hz, 1H), 7.72 (d, J = 8.1 Hz, 1H) , 7.78 (d, J = 7.5 Hz, 1H); 13C NMR (CDCl3, 150.9 MHz): δ 46.9, 52.1,

55.7, 122.1, 126.7, 127.4, 127.7, 127.9, 128.6, 128.8, 131.2, 131.6, 134.0, 137.7, 139.0, 164.0, 166.1; IR

(neat): 3419, 3062, 3030, 2952, 2843, 1716, 1456, 1254, 1159, 1033, 702 cm-1; MS (ESI): m/z = 413

(M+H+); HRMS (ESI) calcd. for C19H17BrN4NaO2: (M+Na+); 435.0433, found: 435.0431;


SI-8


(S)-Methyl 4-(5-(3-bromophenyl)-2H-tetrazol-2-yl)-2-methylene-3-phenylbutanoate (4c)

According to the general procedure, a reaction of 1c (0.1 mmol; 31.1 mg), 3a (0.1 mmol; 19.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4c (25%, 90% ee) as a pale yellow oil and recovered



1H), 5.23 (dd, J = 8.7, 13.2 Hz, 1H), 5.83 (s, 1H), 6.41 (s, 1H), 7.26–7.39 (m, 6H), 7.59 (d, J = 8.1 Hz,

1H), 8.05 (d, J = 7.8 Hz, 1H), 8.28 (s, 1H); 13C NMR (CDCl3, 150.9 MHz): δ 46.7, 52.2, 55.6, 122.9,

125.4, 126.7, 127.7, 127.9, 128.9, 129.3, 129.8, 130.4, 133.2, 137.7, 139.0, 163.7, 166.2; IR (neat): 3423,

3062, 3030, 2952, 2850, 1716, 1437, 1258, 1157, 701 cm-1; MS (ESI): m/z = 413 (M+H+); HRMS (ESI)

calcd. for C19H17BrN4NaO2: (M+Na+); 435.0433, found: 435.0439;



(S)-Methyl 4-(5-(4-bromophenyl)-2H-tetrazol-2-yl)-2-methylene-3-phenylbutanoate (4d)

According to the general procedure, a reaction of 1d (0.1 mmol; 31.1 mg), 3a (0.1 mmol; 19.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4d (38%, 90% ee) as a pale yellow solid and recovered



1H), 5.22 (dd, J = 8.4, 13.5 Hz, 1H), 5.83 (s, 1H), 6.40 (s, 1H), 7.22–7.35 (m, 5H), 7.61 (d, J = 8.4 Hz,

2H), 7.97 (d, J = 8.4 Hz, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 46.7, 52.2, 55.6, 124.6, 126.3, 126.7,

127.7, 127.9, 128.3, 128.8, 132.1, 137.7, 139.0, 164.2, 166.2; IR (KBr): 3412, 3122, 3060, 2956, 2925,

2853, 1719, 1631, 1453, 1275, 1159, 703 cm-1; Mp = 110.6–111.6 ºC; MS (ESI): m/z = 435 (M+Na+);

SI-9

HRMS (ESI) calcd. for C19H17BrN4NaO2: (M+Na+); 435.0433, found: 435.0427;


1.0 mL/min, λ = 254 nm, τmin = 16.8 min, τmaj = 19.5 min); [α]D25= +116.0 (c = 0.45, CHCl3), 90% ee.

(S)-Methyl 2-methylene-3-phenyl-4-(5-o-tolyl-2H-tetrazol-2-yl)butanoate (4e)

According to the general procedure, a reaction of 1e (0.1 mmol; 24.6 mg), 3a (0.1 mmol; 19.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4e (42%, 90% ee) as a pale yellow oil and recovered


1H NMR (CDCl3, 300 MHz): δ 2.54 (s, 3H), 3.69 (s, 3H), 4.83 (dd, J = 8.1, 8.1 Hz, 1H), 5.05 (dd, J = 7.8,

13.5 Hz, 1H), 5.25 (dd, J = 8.4, 13.5 Hz, 1H), 5.83 (s, 1H), 6.40 (s, 1H), 7.22–7.35 (m, 8H), 7.96 (d, J =

8.4 Hz, 1H); 13C NMR (CDCl3, 150.9 MHz): δ 21.6, 46.8, 52.1, 55.4, 125.9, 126.5, 126.6, 127.7, 127.9,

128.8, 129.4, 129.8, 131.3, 137.4, 137.8, 139.2, 165.3, 166.2; IR (neat): 3423, 3063, 3030, 2952, 2858,

1716, 1455, 1251, 1036, 702 cm-1; MS (ESI): m/z = 349 (M+Na+); HRMS (ESI) calcd. for

C20H20N4NaO2: (M+Na+); 371.1484, found: 371.1485;



(S)-Methyl 2-methylene-3-phenyl-4-(5-m-tolyl-2H-tetrazol-2-yl)butanoate (4f)

According to the general procedure, a reaction of 1f (0.1 mmol; 24.6 mg), 3a (0.1 mmol; 19.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4f (58%, 90% ee) as a pale yellow oil and recovered



13.5 Hz, 1H), 5.22 (dd, J = 8.4, 13.5 Hz, 1H), 5.83 (s, 1H), 6.39 (s, 1H), 7.22-7.39 (m, 7H), 7.90–7.94 (m,

2H); 13C NMR (CDCl3, 150.9 MHz): δ 21.4, 46.7, 52.1, 55.5, 124.0, 126.6, 127.2, 127.4, 127.7, 127.9,

SI-10

128.8, 128.8, 131.1, 137.8, 138.6, 139.1, 165.1, 166.2; IR (neat): 3427, 3063, 3030, 2952, 2866, 1716,

1455, 1281, 1158, 1047, 696 cm-1; MS (ESI): m/z = 349 (M+H+); HRMS (ESI) calcd. for C20H20N4NaO2:

(M+Na+); 371.1484, found: 371.1481;



(S)-Methyl 2-methylene-3-phenyl-4-(5-p-tolyl-2H-tetrazol-2-yl)butanoate (4g)

According to the general procedure, a reaction of 1g (0.1 mmol; 24.6 mg), 3a (0.1 mmol; 19.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4g (63%, 90% ee) as a pale yellow solid and recovered



13.5 Hz, 1H), 5.21 (dd, J = 8.4, 12.6 Hz, 1H), 5.83 (s, 1H), 6.39 (s, 1H), 7.25–7.34 (m, 7H), 8.00 (d, J =

8.1 Hz, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 21.5, 46.6, 52.1, 55.5, 124.6, 126.6, 126.7, 127.6, 127.9,

128.8, 129.5, 137.9, 139.1, 140.4, 165.1, 166.2; IR (KBr): 3410, 3119, 3030, 2949, 2862, 1714, 1440,

1243, 1165, 704 cm-1; Mp = 90.0–91.0 ºC; MS (ESI): m/z = 371 (M+Na+); HRMS (ESI) calcd. for

C20H20N4NaO2: (M+Na+); 371.1484, found: 371.1483;

The ee of the product was determined by HPLC using an IA-3 column (n-Hexane/i-PrOH = 80/20, flow

late 0.5 mL/min, λ = 254 nm, τmin = 12.9 min, τmaj = 14.6 min); [α]D25= +109.7 (c = 0.58, CHCl3), 90% ee.

(S)-Methyl 3-(4-bromophenyl)-2-methylene-4-(5-phenyl-2H-tetrazol-2-yl)butanoate (4h)

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3b (0.1 mmol; 27.3 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4h (52%, 86% ee) as a pale yellow solid and recovered

(R)-3b (25%, 87% ee) as a white solid.


SI-11

1H), 5.19 (dd, J = 8.4, 13.2 Hz, 1H), 5.83 (s, 1H), 6.41 (s, 1H), 7.15 (d, J = 8.1 Hz, 2H), 7.41–7.48 (m,

5H), 8.11 (d, J = 3.6 Hz, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 46.3, 52.2, 55.2, 121.7, 126.8, 127.2,

128.9, 129.4, 130.4, 132.0, 136.9, 138.8, 165.1, 166.0; IR (KBr): 3412, 3109, 3006, 2957, 2924, 2852,

1715, 1631, 1487, 1447, 1195, 824, 732 cm-1; Mp = 88.1–88.9 ºC; MS (ESI): m/z = 413 (M+H+); HRMS

(ESI) calcd. for C19H17BrN4NaO2: (M+Na+); 435.0433, found: 435.0434;

The ee of the product was determined by HPLC using an IA-3 column (n-Hexane/i-PrOH = 95/5, flow

late 1.0 mL/min, λ = 254 nm, τmin = 17.5 min, τmaj = 20.0 min); [α]D25= +134.0 (c = 0.66, CHCl3), 86% ee.

(S)-Methyl 3-(4-(trifluoromethyl)phenyl)-2-methylene-4-(5-phenyl-2H-tetrazol-2-yl)butanoate (4i)

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3c (0.1 mmol; 26.2 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4i (47%, 85% ee) as a white solid and recovered (R)-3c



1H), 5.24 (dd, J = 8.4, 13.2 Hz, 1H), 5.87 (s, 1H), 6.44 (s, 1H), 7.41 (d, J = 7.8 Hz, 2H), 7.47–7.49 (m,

3H), 7.57 (d, J = 7.8 Hz, 2H), 8.09–8.12 (m, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 46.6, 52.3, 55.1,

123.9 (q, J = 272.2 Hz), 125.8 (q, J = 3.5 Hz), 126.8, 127.2, 127.3, 128.3, 128.9, 130.0 (q, J = 32.6 Hz),

130.4, 138.5, 141.9, 165.1, 165.8; 19F NMR (CDCl3, 282 MHz): δ -63.1 (s, 3F); IR (KBr): 3421, 3112,

3075, 3005, 2962, 2850, 1721, 1449, 1158, 1069, 853, 732 cm-1; Mp = 87.8–88.9 ºC; MS (ESI): m/z =

403 (M+H+); HRMS (ESI) calcd. for C20H17F3N4NaO2: (M+Na+); 425.1201, found: ; 425.1192;



(S)-Methyl 2-methylene-4-(5-phenyl-2H-tetrazol-2-yl)-3-p-tolylbutanoate (4j)

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3d (0.1 mmol; 20.8 mg),



SI-12

chromatography (n-Hexane/EtOAc) to give (S)-4j (37%, 91% ee) as a white solid and recovered (R)-3d



13.5 Hz, 1H), 5.20 (dd, J = 9.0, 13.2 Hz, 1H), 5.82 (s, 1H), 6.37 (s, 1H), 7.09–7.18 (m, 4H), 7.47 (s, 3H),

8.11 (d, J = 3.6 Hz, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 21.0, 46.3, 52.1 (d, J = 1.7 Hz), 55.6, 126.4,

126.8, 127.4, 127.8, 128.8, 129.5, 130.3, 134.8, 137.3, 139.2, 165.0, 166.2; IR (KBr): 3422, 3110, 3073,

3006, 2959, 2858, 1720, 1449, 1285, 1159, 823, 731 cm-1; Mp = 97.6–98.2 ºC; MS (ESI): m/z = 349

(M+H+); HRMS (ESI) calcd. for C20H20N4NaO2: (M+Na+); 371.1484, found: 371.1482;

The ee of the product was determined by HPLC using an IB column (n-Hexane/CHCl3 = 80/20, flow late

1.0 mL/min, λ = 254 nm, τmin = 20.1 min, τmaj = 21.9 min); [α]D25= +151.9 (c = 0.30, CHCl3), 91% ee.

(S)-Methyl 2-methylene-3-(naphthalen-2-yl)-4-(5-phenyl-2H-tetrazol-2-yl)butanoate (4k)

MeO2C

NN

N N

Ph

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3e (0.1 mmol; 24.4 mg),



chromatography (n-Hexane/EtOAc) to give (S)-4k (49%, 86% ee) as a white solid and recovered (R)-3e

(34%, 90% ee) as a white solid.

1H NMR (CDCl3, 300 MHz): δ 3.67 (s, 3H), 5.00–5.16 (m, 2H), 5.31 (dd, J = 8.7, 13.2 Hz, 1H), 5.91 (s,

1H), 6.44 (s, 1H), 7.39–7.46 (m, 6H), 7.76–7.81 (m, 4H), 8.11 (d, J = 4.2 Hz, 2H); 13C NMR (CDCl3,

150.9 MHz): δ 46.7, 52.2 (d, J = 1.8 Hz), 55.5, 125.8, 126.1, 126.3, 126.8, 126.9, 127.3, 127.6, 127.9,

128.6, 128.8, 130.3, 132.7, 133.3, 135.3, 139.0, 165.0, 166.2; IR (KBr): 3406, 3118, 3071, 3051, 2955,

2851, 1920, 1704, 1628, 1438, 1287, 1157, 702 cm-1; Mp = 130.8–131.9 ºC; MS (ESI): m/z = 407

(M+Na+); HRMS (ESI) calcd. for C23H20N4NaO2: (M+Na+); 407.1484, found: 407.1488;



(S)-Methyl 3-cyclohexyl-2-methylene-4-(5-phenyl-2H-tetrazol-2-yl)butanoate (4l)

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3f (0.1 mmol; 20.0 mg),

SI-13

(DHQD)2PHAL (0.01 mmol; 7.8 mg) and MS 4Å (10.0 mg) in 0.33 mL dry 1,4-dioxane (0.3 M) at

ambient temperature for 120 h afforded the crude mixture. The residue was purified by silica gel column

chromatography (n-Hexane/EtOAc) to give (S)-4l (28%, 86% ee) as a colorless oil and recovered (R)-3f


1H NMR (CDCl3, 300 MHz): δ 0.91–1.78 (m, 10H), 1.99 (d, J = 10.8 Hz, 1H), 3.10-3.11 (m, 1H), 3.76 (s,

3H), 4.86 (dd, J = 5.4, 13.2 Hz, 1H), 5.02 (dd, J = 13.2, 13.2 Hz, 1H), 5.39 (s, 1H), 6.12 (s, 1H), 7.47 (s,

3H), 8.11 (d, J = 4.2 Hz, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 26.1, 26.1, 26.2, 30.9, 31.2, 38.2, 53.7,

126.8, 127.5, 128.5, 128.8, 130.2, 137.9, 164.9, 166.6; IR (neat): 3419, 3071, 2926, 2852, 1717, 1626,

1529, 1449, 1264, 1197, 734 cm-1; MS (ESI): m/z = 363 (M+Na+); HRMS (ESI) calcd. for

C19H24N4NaO2: (M+Na+); 363.1797, found: 363.1803;

The ee of the product was determined by HPLC using an IB column (n-Hexane/CHCl3 = 90/10, flow late

1.5 mL/min, λ = 254 nm, τmaj = 13.5 min, τmin = 19.7 min); [α]D25= -41.2 (c = 0.31, CHCl3), 86% ee.

(S)-tert-Butyl 2-methylene-3-phenyl-4-(5-phenyl-2H-tetrazol-2-yl)butanoate (4m)

According to the general procedure, a reaction of 1a (0.1 mmol; 23.2 mg), 3g (0.1 mmol; 23.6 mg),

(DHQD)2PHAL (0.01 mmol; 7.8 mg) and MS 4Å (10.0 mg) in 0.33 mL dry 1,4-dioxane (0.3 M) at

ambient temperature for 48 h afforded the crude mixture. The residue was purified by silica gel column

chromatography (n-Hexane/EtOAc) to give (S)-4m (45%, 87% ee) as a white solid and recovered (R)-3g

(43%, 85% ee) as a white solid.


1H), 5.19 (dd, J = 8.4 13.5 Hz, 1H), 5.70 (s, 1H), 6.32 (s, 1H), 7.25 (s, 5H), 7.47 (s, 3H), 8.11 (d, J = 3.6

Hz, 2H); 13C NMR (CDCl3, 150.9 MHz): δ 27.9, 46.7, 55.7, 81.5, 125.5, 126.8, 127.4, 127.5, 127.9, 128.7,

128.8, 130.2, 138.2, 140.8, 164.9, 164.9; IR (KBr): 3402, 3111, 2998, 2929, 1712, 1631, 1451, 1291,

1156, 855, 697 cm-1; Mp = 92.1–93.0 ºC; MS (ESI): m/z = 377 (M+H+); HRMS (ESI) calcd. for

C22H24N4NaO2: (M+Na+); 399.1797, found: 399.1795;



Quantification of apoptosis by annexin V

Detection of apoptosis was performed using the MuseTM Annexin V and Dead Cell Assay Kit

(Merck Millipore Corporation, Darmstadt, Germany) and Muse Cell Analyzer (Merck Millipore

Corporation) according to the manufacturer’s protocols. Cells incubated in the presence or

SI-14

absence of racemic-3 for 24 h were collected by centrifugation (2,000 rpm at 4 °C for 5 min).

Cells were suspended in 100 μL of RPMI 1640 medium, and incubated with 100μL of annexin V

reagent at room temperature for 20 min. These cells were measured by Muse Cell Analyzer.

SI-15

(R)-3a

HPLC using an IB column

(n-Hexane/CHCl3 = 98/2, flow rate 1.0 mL/min, λ = 254 nm)

No. tR (min) Area (%) High (%) No. tR (min) Area (%) High (%)

1 9.458 49.839 62.037 1 9.517 12.518 17.474

2 13.283 50.161 37.963 2 13.175 87.482 82.526

(R)-3b

HPLC using an IA-3 column



1 17.600 49.571 63.583 1 18.133 93.512 94.811

2 21.042 50.429 36.417 2 22.417 6.488 5.189

SI-16

(R)-3c




1 16.942 49.987 54.504 1 18.117 5.214 6.863

2 18.142 50.013 45.596 2 19.167 94.786 93.137

(R)-3d




1 17.875 49.932 57.800 1 18.867 6.264 8.346

2 20.933 50.068 42.200 2 21.867 93.736 91.654

F

MeO2C

CF3

SI-17

(R)-3e




1 40.650 49.166 51.106 1 41.258 5.201 7.432

2 44.200 50.834 48.894 2 43.825 94.799 92.568

(R)-3f

HPLC using an IC column

(n-Hexane/i-PrOH = 98/2, flow rate 0.5 mL/min, λ = 254 nm)


1 8.342 49.497 50.300 1 9.058 25.982 30.171

2 8.808 50.503 49.700 2 9.950 74.018 69.829

SI-18

(R)-3g




1 12.833 49.997 52.602 1 12.833 7.694 8.590

2 14.675 50.003 47.398 2 14.617 92.306 91.410

SI-19

(S)-4a




1 21.200 49.975 54.254 1 20.925 96.166 95.681

2 23.967 50.025 45.746 2 23.875 3.834 4.319

(S)-4b




1 8.292 49.873 53.467 1 8.217 90.983 91.716

2 9.867 50.127 46.533 2 9.800 9.017 8.284

SI-20

(S)-4c




1 7.550 49.961 54.996 1 7.717 94.967 95.881

2 9.633 50.039 45.004 2 10.100 5.033 4.119

(S)-4d




1 18.308 49.971 60.724 1 16.758 4.821 5.958

2 25.842 50.029 39.276 2 19.492 95.179 94.042

SI-21

(S)-4e




1 6.867 49.787 53.668 1 6.825 94.946 95.497

2 8.533 50.213 46.332 2 8.367 5.054 4.503

(S)-4f




1 9.025 49.974 53.945 1 8.850 95.030 95.543

2 10.925 50.053 46.055 2 10.625 4.970 4.457

SI-22

(S)-4g




1 16.817 49.923 53.325 1 12.867 4.801 6.103

2 19.083 50.077 46.675 2 14.567 95.199 93.897

(S)-4h




1 18.042 49.412 53.526 1 17.450 7.116 8.420

2 20.800 50.588 46.747 2 20.025 92.884 91.580

SI-23

(S)-4i




1 10.975 49.914 52.883 1 10.958 92.698 92.999

2 12.558 50.086 47.117 2 12.600 7.302 7.001

(S)-4j




1 20.042 49.593 52.105 1 20.133 4.318 7.948

2 22.533 50.407 47.895 2 21.933 95.682 92.052

SI-24

(S)-4k




1 21.800 50.165 61.074 1 21.517 93.075 94.648

2 33.700 49.835 38.926 2 34.100 6.925 5.352

(S)-4l




1 13.658 49.293 59.683 1 13.500 7.024 15.069

2 21.142 50.707 40.317 2 19.742 92.976 84.931

SI-25

(S)-4m




1 27.208 50.009 56.211 1 27.725 6.457 9.024

2 32.008 49.991 43.789 2 31.600 93.543 90.976

SI-27

PhMeO2C

NN

N NBr

4b1H NMR

PhMeO2C

NN

N NBr

4b13C NMR

synthesis of chiral (tetrazolyl)methyl-containing ... · pdf filesilicon-induced...

Documents