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D. Guerin et al. / C. R. Chimie xxx (2017) 1e9
7
The mixture was heated to 40 ꢀC and stirred for 24 h. The
4.2.4. (Z)-tert-Butyl but-3-en-1-yloxy(2-fluoro-3-phenylallyl)
carbamate (6b)
reaction was stopped by adding NH4Cl (20 mL) and
extracted with DCM (3 ꢂ 25 mL). The organic layers were
combined and dried over anhydrous MgSO4. After filtration
and evaporation of the volatile materials under reduced
pressure, the crude material was purified by flash chro-
matography on silica gel (cyclohexane/DCM ¼ 7:3,
Rf ¼ 0.44) to afford 2b (211 mg, 70%) as a colorless oil.
A 100 mL two-neck flask equipped with a stir bar and a
reflux condenser was flushed with argon. A solution of tert-
butyl but-3-en-1-yloxycarbamate (1 equiv, 300 mg,
1.6 mmol) in THF (10 mL) was prepared. NaH (2 equiv,
76.9 mg, 3.20 mmol) was added. At the end of the bubbling,
the mixture was cooled down to 0 ꢀC and the tosylate
(1.2 equiv, 589 mg, 1.92 mmol) in a solution of THF was
added slowly. The mixture was stirred for 5 h. The reaction
was monitored by TLC and 19F NMR. When full consump-
tion of starting material was observed, the reaction was
stopped by adding NH4Cl (10 mL) and extracted with DCM
(3 ꢂ 15 mL). The organic layers were combined and dried
over anhydrous MgSO4. After filtration and evaporation of
the volatile materials under reduced pressure, the crude
material was purified by flash chromatography on silica gel
(cyclohexane/DCM ¼ 7:3, Rf ¼ 0.43) to afford 6b (283 mg,
55%) as a colorless oil.
1H NMR (400.13 MHz, CDCl3):
d
5.84 (ddt, 3JH-H ¼ 17 Hz,
3
3JH-H ¼ 10 Hz, JH-H ¼ 7 Hz, 1H, HC¼CH2), 5.10 (m, 2H,
HC¼CH2), 4.74 (dd, 3JF-H ¼ 16 Hz, 3JF-H ¼ 3 Hz, 1H, FC¼CH2),
3
3
4.52 (dd, JF-H ¼ 48 Hz, JF-H ¼ 3 Hz, 1H, FC¼CH2), 4.13 (d,
3JH-F ¼ 13 Hz, 2H, NeCH2), 3.95 (t, JH-H ¼ 7 Hz, 2H, O
3
eCH2), 2.38 (dt, 3JH-H ¼ 7 Hz, 3JH-H ¼ 7 Hz, 2H, CH2) 1.51 (s,
9H, C(CH3)3); 19F NMR (376.50 MHz, CDCl3):
d
ꢁ103.54
(ddt, JF-H ¼ 48 Hz, JF-H ¼ 16 Hz, JF-H ¼ 13 Hz, 1F); 13C
3
3
3
NMR (75.47 MHz, CDCl3):
d
160.6 (d, 1JC-F ¼ 260 Hz, 1C, CF),
156.3 (s, 1C, NeC¼O), 134.4 (s, 1C, HC¼CH2), 116.5 (s, 1C,
3
HC¼CH2), 93.4 (d, JC-F ¼ 17 Hz, 1C, FC¼CH2), 81.9 (s, 1C,
2
C(CH3)3), 74.4 (s, 1C, OeCH2), 50.6 (d, JC-F ¼ 31 Hz, 1C, N
1H NMR (400.13 MHz, CDCl3):
d 7.27 (m, 5H, ArH), 5.74
eCH2), 32.3 (s, 1C, CH2)28.1 (3C, C(CH3)3).
(ddt, 3JH-H ¼ 17 Hz, 3JH-H ¼ 10 Hz, 3JH-H ¼ 7 Hz, 1H, HC¼CH2),
3
IR (neat)
n
2955, 2936, 1699, 1495, 1461, 1445, 1421,
5.63 (d, JH-F ¼ 38 Hz, 1H, FC¼CH), 5.00 (m, 2H, HC¼CH2),
1371, 1226, 1152, 1105, 1073, 989, 854, 827 cmꢁ1; HRMS
(ESIþ): m/z ¼ 268.1333 [MþNa]þ, calcd for C12H20FNO3Na:
268.1325.
4.18 (d, 3JH-F ¼ 16 Hz, 2H, NeCH2), 3.89 (t, 3JH-H ¼ 7 Hz, 2H, O
3
eCH2), 2.30 (q, JH-H ¼ 7 Hz, 2H, OeCH2eCH2), 1.44 (s, 9H,
C(CH3)3); 19F NMR (376.50 MHz, CDCl3):
d
ꢁ108.95 (dt, 3JF-
3
¼ 38 Hz, JF-H ¼ 16 Hz, 1F); 13C NMR (75.47 MHz, CDCl3):
H
4.2.3. (Z)-tert-Butyl allyloxy(2-fluoro-3-phenylallyl)carbamate
(6a)
d
156.3 (s,1C, NeC¼O),153.5 (d, 1JC-F ¼ 269 Hz,1C, CF),134.6
3
(s, 1C, HC¼CH2), 132.8 (d, JC-F ¼ 3 Hz, 1C, ArC), 128.7 (2C,
6
A 100 mL two-neck flask equipped with a stir bar and a
reflux condenser was flushed with argon. A solution of tert-
butyl allyloxycarbamate (1 equiv, 400 mg, 2.31 mmol) in
THF (20 mL) was prepared. NaH (2 equiv, 110.8 mg,
4.62 mmol) was added. At the end of the bubbling, the
mixture was cooled down to 0 ꢀC and the tosylate
(1.2 equiv, 849 mg, 2.77 mmol) in a solution of THF was
added slowly. The mixture was stirred for 5 h. The reaction
was monitored by TLC and 19F NMR. When full consump-
tion of the starting material was observed, the reaction was
stopped by adding NH4Cl (20 mL) and extracted with DCM
(3 ꢂ 25 mL). The organic layers were combined and dried
over anhydrous MgSO4. After filtration and evaporation of
the volatile materials under reduced pressure, the crude
material was purified by flash chromatography on silica gel
(cyclohexane/DCM ¼ 7:3, Rf ¼ 0.39) to afford 6a (461 mg,
65%) as a colorless oil.
ArCH), 128.5 (2C, ArCH), 127.5 (d, JC-F ¼ 2 Hz, 1C, ArCH),
2
116.7 (s, 1C, HC¼CH2), 109.4 (d, JC-F ¼ 7 Hz, 1C, FC¼CH),
2
82.1 (s, 1C, C(CH3)3), 74.6 (s, 1C, OeCH2), 51.8 (d, JC-
¼ 30 Hz, 1C, NeCH2), 32.6 (s, 1C, OeCH2eCH2), 28.3 (3C,
F
C(CH3)3).
IR (neat)
n 2978, 1702, 1642, 1495, 1476, 1451, 1418, 1367,
1232, 1156, 1090, 1028, 991, 915, 876, 852, 753, 693 cmꢁ1
;
HRMS (ESIþ): m/z ¼ 344.1646 [MþNa]þ, calcd for
C
18H24FNO3Na: 344.1638.
4.2.5. (Z)-tert-Butyl (2-fluoro-3-phenylallyl)(pent-4-en-1-
yloxy)carbamate (6c)
A 50 mL two-neck flask equipped with a stir bar and a
reflux condenser was flushed with argon. A solution of tert-
butyl but-3-en-1-yloxycarbamate (1 equiv, 300 mg,
1.49 mmol) in THF (5 mL) was prepared. NaH (2 equiv,
71.54 mg, 2.98 mmol) was added. At the end of the
bubbling, the mixture was cooled down to 0 ꢀC and the
tosylate (1.2 equiv, 548 mg, 1.79 mmol) in a solution of THF
was added slowly. The mixture was stirred for 5 h. The
reaction was monitored by TLC and 19F NMR. When full
consumption of the starting material was observed, the
reaction was stopped by adding NH4Cl (5 mL) and extracted
with DCM (3 ꢂ 5 mL). The organic layers were combined
and dried over anhydrous MgSO4. After filtration and
evaporation of the volatile materials under reduced pres-
sure, the crude material was purified by flash chromatog-
raphy on silica gel (cyclohexane/CH2Cl2 ¼ 7:3, Rf ¼ 0.43) to
afford 6c (320 mg, 64%) as a colorless oil.
1H NMR (400.13 MHz, CDCl3):
d 7.27 (m, 5H, ArH), 5.90
(ddt, 3JH-H ¼ 17 Hz, 3JH-H ¼ 10 Hz, 3JH-H ¼ 6 Hz, 1H, HC¼CH2),
3
5.65 (d, JH-F ¼ 38 Hz, 1H, FC¼CH), 5.21 (m, 2H, HC¼CH2),
4.33 (d, 3JH-H ¼ 6 Hz, 2H, OeCH2), 4.20 (d, 3JH-F ¼ 16 Hz, 2H,
NeCH2), 1.45 (s, 9H, C(CH3)3); 19F NMR (376.50 MHz,
3
3
CDCl3):
d
ꢁ108.84 (dt, JF-H ¼ 38 Hz, JF-H ¼ 16 Hz, 1F); 13C
NMR (75.47 MHz, CDCl3):
d
156.3 (s, 1C, NeC¼O), 156.0 (d,
1JC-F ¼ 269 Hz, 1C, CF), 132.7 (d, JC-F ¼ 3 Hz, 1C, ArC), 132.3
(s, 1C, HC¼CH2), 128.6 (2C, ArCH), 128.4 (2C, ArCH), 127.3 (d,
3
6JC-F ¼ 2 Hz, 1C, ArCH), 119.8 (s, 1C, HC¼CH2), 109.2 (d, JC-
2
¼ 7 Hz, 1C, FC¼CH), 81.9 (s, 1C, C(CH3)3), 76.6 (s, 1C, O
F
eCH2), 51.8 (d, 2JC-F ¼ 30 Hz, 1C, NeCH2), 28.1 (3C, C(CH3)3).
IR (neat)
n
2979, 2933, 1702, 1495, 1476,1451, 1367,1232,
1H NMR (400.13 MHz, CDCl3):
d 7.51e7.23 (m, 5H, ArH),
1155,1089, 991, 932, 876, 851, 754, 693 cmꢁ1; HRMS (ESIþ):
m/z ¼ 330.1484 [MþNa]þ, calcd for C17H22FNO3Na:
330.1481.
5.78 (ddt, JH-H ¼ 17 Hz, JH-H ¼ 10 Hz, JH-H ¼ 7 Hz, 1H,
3
3
3
3
HC¼CH2), 5.70 (d, JH-F ¼ 38 Hz, 1H, FC¼CH), 4.97 (m, 2H,
3
3
HC¼CH2), 4.26 (d, JH-F ¼ 16 Hz, 2H, NeCH2), 3.92 (t, JH-
ꢀ
Please cite this article in press as: D. Guerin, et al., Ring-closing metathesis of fluoroalkenes toward the synthesis of fluorinated