References and Notes
-
1a
Hoye TR.
Danielson ME.
May AE.
Zhao H.
Angew. Chem. Int. Ed.
2008,
47:
9743
-
1b
Aponick A.
Li C.
Palmes JA.
Org.
Lett.
2009,
11:
121
-
1c
Barluenga J.
Fernández A.
Satrústegui A.
Diéguez A.
Rodríguez F.
Fañanás FJ.
Chem.
Eur. J.
2008,
14:
4153
-
1d
Matano Y.
Miyajima T.
Ochi N.
Nakao Y.
Sakaki S.
Imahori H.
J. Org. Chem.
2008,
73:
5139
-
1e
Song Y.
Hwang S.
Gong P.
Kim D.
Kim S.
Org. Lett.
2008,
10:
269
-
2a
Lu Z.
Chai G.
Ma S.
J. Am. Chem. Soc.
2007,
129:
14546
-
2b
Lu Z.
Chai G.
Zhang X.
Ma S.
Org. Lett.
2008,
10:
3517
-
2c
Chai G.
Lu Z.
Fu C.
Ma S.
Adv. Synth. Catal.
2009,
351:
1946
- 3
Chen B.
Lu Z.
Chai G.
Fu C.
Ma S.
J. Org. Chem.
2008,
73:
9486
- 4
Howells RD.
Gilman H.
J. Fluorine Chem.
1975,
5:
99
- 5
Haszeldine RN.
J.
Chem. Soc.
1953,
1748
- 6
Omote M.
Eto Y.
Tarui A.
Sato K.
Ando A.
Tetrahedron:
Asymmetry
2007,
18:
2768
- 7
Sokeirik YS.
Hoshina A.
Omote M.
Sato K.
Tarui A.
Kumadaki I.
Ando A.
Chem. Asian
J.
2008,
3:
1850
- 8 For a recent study on the reaction
of n-C4F9Ti(Oi-Pr)4MgBr with carboxylates
to afford perfluoroalkyl sec-alcohol,
see: Mikami K.
Murase T.
Itoh Y.
J. Am. Chem. Soc.
2007,
129:
11686
-
For the reaction of perfluoroalkyl
lithium reagents with ester, acyl fluoride, and anhydride affording
mixtures of perfluoroalkyl-containing alcohols and ketones, see:
-
9a
Kokotos CG.
Baskakis C.
Kokotos G.
J. Org. Chem.
2008,
73:
8623
-
9b
Gassman PG.
O’Reilly NJ.
J.
Org. Chem.
1987,
52:
2481
-
For the reaction of normal carboxylates
with RfI in the presence of MeLi-LiBr affording
perfluoroalkyl ketones, see:
-
10a
Robert JC.
Timothy TC.
William AM.
J. Fluorine Chem.
1998,
88:
71
-
10b
Rong G.
J.
East China Univ. Sci. Tech.
1996,
22:
356
-
10c
Uno H.
Shiraishi Y.
Suzuki H.
Bull.
Chem. Soc. Jpn.
1989,
62:
2636
-
10d
Uno H.
Shiraishi Y.
Simokawa K.
Suzuki H.
Chem. Lett.
1987,
6:
1153
- 11 For the reaction of anhydride or
acyl chloride with RfMgX reagents to afford perfluoroalkyl
ketones, see: Patrice M.
Naima N.
Auguste C.
J. Fluorine Chem.
1987,
34:
421
-
For the reaction of perfluoroalkylated
ester or carboxylic acid with organometallic reagents (LDA, PhLi,
Al/HgCl2, MeMgBr, and NaOCH3) to
afford the perfluoroalkyl ketones, see:
-
12a
Reeves JT.
Song JJ.
Tan Z.
Lee H.
Yee NK.
Senanayake CH.
J.
Org. Chem.
2008,
73:
9476
-
12b
Jiang X.
Kakuda K.
Matsukawa S.
Yamamichi H.
Kojima S.
Yamamoto Y.
Chem. Asian J.
2007,
2:
314
-
12c
Konno T.
Takehana T.
Mishima M.
Ishihara T.
J. Org. Chem.
2006,
71:
3545
-
12d
Zeifman YV.
Postovoi SA.
J.
Fluorine Chem.
2004,
125:
1815
-
12e
Croxtall B.
Fawcett J.
Hope EG.
Stuart AM.
J. Fluorine
Chem.
2003,
119:
65
-
12f
Kitazume T.
Ohnogi T.
Lin JT.
Yamazaki T.
J. Fluorine Chem.
1989,
42:
17
- 13
Trost BM.
Pinkerton AB.
Seidel M.
J.
Am. Chem. Soc.
2001,
123:
12466
- 16
Ma S.
Li L.
Org. Lett.
2000,
2:
941
- 18
Hoffmann-Röder A.
Krause N.
Org. Lett.
2001,
3:
2537
14 Perfluoroalkyl iodides are commercially
available.
15
Method A
To
a dried Schlenk tube were added n-C4F9I
(0.36 mL, d = 2.01
g/mL, 0.72 g, 2.09 mmol) and anhyd Et2O (2.5
mL). The resulting mixture was cooled to -80 ˚C
in a cooling bath and a solution of EtMgBr (0.47 mL, 3.0 M in Et2O,
1.41 mmol) was added dropwise at -80 ˚C
with stirring. After the addition, anhyd Et2O (0.7 mL)
was used to rinse the remaining EtMgBr. The resulting mixture was
stirred for 70 min at this temperature. A solution of 1b (81.0 mg, 0.40 mmol) in anhyd Et2O
(1 mL) was added dropwise at -80 ˚C with
stirring. Then the mixture was allowed to warm up to
-70 ˚C
within 30 min and stirred at -70 ˚C for
6 h. The mixture was quenched with 5 mL of a sat. aq NH4Cl
solution at -70 ˚C. After being warmed
up to r.t. naturally, the mixture was extracted with Et2O
(3 × 20 mL). The combined organic extracts were washed
with brine (5 mL) and dried over anhyd Na2SO4.
Filtration, evaporation, and chromatography on silica gel [eluent:
petroleum ether (bp 60-90 ˚C)] afforded 2a (111.0 mg, 74%) as a liquid. ¹H NMR
(300 MHz, CDCl3): δ = 7.42-7.23
(m, 5 H), 6.69 (q, J = 2.6
Hz, 1 H), 2.03 (d, J = 2.6
Hz, 3 H). ¹³C NMR (75 MHz, CDCl3): δ = 217.1,
183.4 (t, J = 23.9
Hz), 130.6, 129.0, 128.5, 127.7, 102.8, 98.8, 14.5. ¹9F
NMR (282 MHz, CDCl3): δ = -80.6
to -81.2 (m, 3 F), -113.5 to -114.0 (m,
2 F), -121.7 to -122.3 (m, 2 F), -125.1
to -125.7 (m, 2 F). MS (EI, 70 ev): m/z (%) = 377
(3.89) [M+ + 1],
376 (24.69) [M+], 129 (100).
IR (neat): 3068, 3035, 2933, 1936, 1700, 1601, 1498, 1462, 1354,
1306, 1240, 1137, 1065, 1048, 1004 cm-¹. HRMS: m/z calcd for C15H9F9O:
376.0510; found: 376.0517.
Method B
To
a dried Schlenk tube were added n-C6F13I
(0.45 mL, d = 2.06
g/mL, 0.93 g, 2.09 mmol) and anhyd Et2O (2.5
mL). The resulting mixture was cooled to -80 ˚C
in a cooling bath, and a solution of PhMgBr (0.48 mL, 3.0 M in Et2O, 1.44
mmol) was added dropwise at -80 ˚C with
stirring within 5 min. After the addition, anhyd Et2O
(0.7 mL) was used to rinse the remaining PhMgBr. Then, the resulting mixture
was stirred for 85 min at this temperature. A solution of 1b (80.3 mg, 0.40 mmol) in anhyd Et2O
(1 mL) was added dropwise at -80 ˚C with
stirring. Then the mixture was allowed to warm up to -70 ˚C
within 30 min and stirred at
-70 ˚C
for 16 h. The mixture was quenched with a sat. aq NH4Cl
solution (5 mL) at -70 ˚C. After being
warmed up to r.t. naturally, the mixture was extracted with Et2O
(3 × 20 mL). The combined organic extracts were washed
with brine (5 mL) and dried over anhyd Na2SO4.
After filtration, evaporation of the solvent, chromatography on
silica gel [eluent: petroleum ether (bp 60-90 ˚C)] afforded 2b [132.1 mg, 70%, eluent:
petroleum ether (bp 60-90 ˚C)] as
a yellow liquid. ¹H NMR (300 MHz, CDCl3): δ = 7.44-7.24
(m, 5 H), 6.69 (m, 1 H), 2.03 (d, J = 2.3
Hz, 3 H). ¹³C NMR (75 MHz, CDCl3): δ = 217.1,
183.4 (t, J = 23.9
Hz), 130.5, 129.0, 128.5, 127.7, 102.8, 98.7, 14.6. ¹9F
NMR (282 MHz, CDCl3): δ = -80.8
to -81.0 (m, 3 F), -113.5 to -113.8 (m,
2 F), -121.1 to -121.7 (m, 4 F), -122.7
to -123.1 (m, 2 F), -126.1 to -126.4
(m, 2 F). MS (EI, 70 ev): m/z (%) = 477 (4.78) [M+ + 1],
476 (25.60) [M+], 129 (100).
IR (neat): 3035, 2934, 1936, 1703, 1600, 1498, 1461, 1364, 1315, 1240,
1205, 1145, 1071, 1015 cm-¹. HRMS: m/z calcd for C17H9F13O:
476.0446; found: 476.0447.
17
4-Allyl-3-methyl-2-(
n
-perfluorobutyl)-5-phenylfuran (8a)
To
a reaction tube was added 2a (76.2 mg,
0.20 mmol), allyl bromide (128.2 mg, 1.0 mmol, purity: 97%),
DMA (2 mL), and PdCl2 (2.2 mg, 0.01 mmol) at r.t. Then
the resulting mixture was stirred at 50 ˚C for
20.5 h as monitored by TLC (PE). After the reaction was complete,
the mixture was quenched with H2O (5 mL). The aqueous
layer was extracted with Et2O (5 × 15 mL) and
dried over anhyd Na2SO4. Filtration, evaporation,
and chromatography on silica gel (eluent: n-hexane)
of the crude product afforded 8a (69.8 mg,
83%) as a colorless liquid. ¹H NMR
(300 MHz, CDCl3): δ = 7.64-7.55
(m, 2 H), 7.47-7.31 (m, 3 H), 6.10-5.94 (m, 1 H),
5.21-5.11 (m, 1 H), 5.07-4.95 (m, 1 H), 3.40-3.32
(m, 2 H), 2.12 (t, J = 2.3
Hz, 3 H). ¹³C NMR (75 MHz, CDCl3): δ = 152.3,
134.6, 134.4 (t, J = 29.6
Hz), 130.0, 128.7, 128.4, 127.8, 126.3, 119.6, 116.1, 27.8, 8.0. ¹9F
NMR (282 MHz, CDCl3): δ = -80.9
to -81.2 (m, 3 F), -110.9 to -111.2 (m,
2 F), -123.8 to -124.1 (m, 2 F), -126.3
to -126.6 (m, 2 F). MS (EI, 70 ev): m/z (%) = 417
(8.38) [M+ + 1],
416 (43.60) [M+], 247 (100).
IR (neat): 3085, 3064, 2930, 1640, 1582, 1494, 1448, 1415, 1352,
1236, 1206, 1135, 1101, 1075, 1030
cm-¹.
HRMS: m/z calcd for C18H13F9O:
416.0823; found: 416.0822.
19
3-Methyl-2-
n
-perfluorobutyl-5-phenylfuran
(8b)
To a dried Schlenk tube was added 2a (112.1
mg, 0.30 mmol), anhyd CH2Cl2 (1.5 mL), and
AuCl3 (4.5 mg, 5 mol%) under the atmosphere
of N2 at r.t. The resulting mixture was stirred for 24
h at r.t. as monitored by TLC (petroleum ether) followed by the
addition of Et2O (20 mL). Evaporation and purification
by flash chromatography on silica gel [eluent: petroleum
ether (bp 60-90 ˚C)] afforded 8b (103.4 mg, 92%) as a colorless
liquid. ¹H NMR (300 MHz, CDCl3): δ = 7.72-7.62
(m, 2 H), 7.45-7.27 (m, 3 H), 6.56 (s, 1 H), 2.21 (t, J = 2.4 Hz,
3 H). ¹³C NMR (75 MHz, CDCl3): δ = 155.8,
134.8 (t, J = 31.7
Hz), 129.4, 128.8, 128.7, 127.6, 124.4, 109.4, 10.0. ¹9F
NMR (282 MHz, CDCl3): δ = -80.9
to -81.2 (m, 3 F), -110.9 to -111.1 (m,
2 F), -123.8 to
-124.1 (m, 2 F), -126.3
to -126.6 (m, 2 F). MS (EI, 70 ev): m/z (%) = 377
(7.99) [M+ + 1],
376 (48.23) [M+], 207 (100). IR
(neat): 3039, 2939, 1626, 1551, 1488, 1451, 1401, 1351, 1236, 1206,
1135, 1087, 1056, 1005 cm-¹. HRMS: m/z calcd for C15H9F9O:
376.0510; found: 376.0509.