Y. Sugiyama et al. / Tetrahedron 71 (2015) 4958e4966
4963
(hexane) to give 5c(11.7 g, 84%) as a paleyellowsolid;mp 120e121 ꢀC;
H2O, dried over Na2SO4 and concentrated. Sodium borohydride
(NaBH4) (5.3 g, 140 mmol) was added to the above residue in dry
THF/dry MeOH (200 mL, 1/1 v/v) at 0 ꢀC. The reaction mixture was
warmed to room temperature and then stirred for 30 min. The
reaction was quenched with 1.0 M HCl aq The organic layer was
washed with H2O, dried over Na2SO4 and concentrated. The crude
residue was purified by silica gel chromatography (EtOAc/Hex¼1:5)
to give 7a (13.6 g, 72%) as a pale yellow solid; mp 87e88 ꢀC; 1H NMR
1H NMR (270 MHz, CDCl3)
d 3.97 (s, 2H), 6.17e6.32 (m, 2H), 7.21e7.29
(m, 2H), 7.52 (d, J¼7.8 Hz, 2H), 7.70 (s, 2H), 7.82 (d, J¼7.8 Hz, 2H); 13
C
NMR (67.8 MHz, CDCl3)
d 36.5, 108.6e120.7 (6C), 124.1, 127.1, 132.7,
132.8, 139.7, 139.9, 142.8, 144.4; 19F NMR (466 MHz, CDCl3)
d
ꢁ80.1
(6F), ꢁ111.8 (4F), ꢁ127.4 (4F); IR (neat) 3010, 2971, 1741, 1652, 1472,
1422, 1352, 1215, 1172,1110,1087, 972, 947, 821, 715, 692 cmꢁ1; HRMS
[FABþ] m/z calcd for C23H13F14 555.0795 found 555.0745.
(270 MHz, CDCl3)
d 2.33e2.53 (m, 4H), 2.97e3.03 (m, 4H), 4.08 (s,
4.5. A procedure for hydrogenation
3H), 7.23e7.26 (m, 2H), 7.46 (s, 2H), 7.69 (d, J¼7.6 Hz, 2H); 13C NMR
(67.8 MHz, CDCl3)
d 26.57 (2C), 26.63 (2C), 50.2, 65.0, 108.5e121.7
4.5.1. 2,7-Bis(3,3,4,4,5,5,6,6,6-nonafluorohexyl)-9H-fluorene
(6a). 5a (18.4 g, 28.0 mmol) and Pd/C (167 mg, 1.4 mmol) in THF/
MeOH (400 mL, 1/1 v/v) was stirred at room temperature for 24 h
under H2 balloon. The catalyst was removed by filtration through
a pad of Celite and washed with ethyl acetate. The filtrate was
concentrated to give 6a (18.5 g, quant) as a pale yellow solid. The
product was used in the next reaction without further purification;
(8C), 124.7 (2C), 127.7 (2C), 138.1 (2C), 140.0 (2C), 145.1 (4C); 19F
NMR (466 MHz, CDCl3)
d
ꢁ80.9 (6F), ꢁ114.7 (4F), ꢁ124.4 (4F),
ꢁ125.9 (4F); IR (neat) 3362, 3004, 2971, 1472, 1455, 1358, 1209,
1167, 1127, 1088, 1065, 974, 852, 815, 743, 706 cmꢁ1; HRMS [FABþ]
m/z calcd for C26H15OF18 689.1077 found 689.1035.
4.6.2. (2,7-Bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)-9H-fluo-
ren-9-yl)methanol (7b). The same procedure employed above for
compound 7a was repeated using 6b (1.1 g, 1.3 mmol), dry Et2O
(65 mL), NaH (505 mg, 12.7 mmol), HCO2Et (10 mL, 127 mmol),
NaBH4 (240 mg, 6.3 mmol) and dry THF/dry MeOH (110 mL, 1/1 v/
v). The crude residue was purified by silica gel chromatography
(EtOAc/hexane¼1/5) to give 7b (1.07 g, 93%) as a pale yellow solid;
mp 128e129 ꢀC; 1H NMR (270 MHz, CDCl3)
d 2.27e2.52 (m, 4H),
2.96e3.02 (m, 4H), 3.87 (s, 2H), 7.22 (d, J¼7.3 Hz, 2H), 7.40 (s, 2H),
7.71 (d, J¼7.6 Hz, 2H); 13C NMR (67.8 MHz, CDCl3)
d 26.5 (2C), 26.6
(2C), 36.7, 108.5e121.7 (8C), 125.0 (2C), 127.0 (2C), 137.7 (2C), 140.1
(2C), 143.9 (4C); 19F NMR (466 MHz, CDCl3)
d
ꢁ80.9 (6F), ꢁ114.8
(4F), ꢁ124.3 (4F), ꢁ125.9 (4F); IR (neat) 3009, 2971,1472,1422,1357,
1299, 1211, 1169, 1131, 1084, 853, 742, 704 cmꢁ1; HRMS [FABþ] m/z
calcd for C25H17F18 659.1045 found 659.1020.
mp 95e96 ꢀC; 1H NMR (270 MHz, CDCl3)
d 2.33e2.53 (m, 4H),
2.97e3.03 (m, 4H), 4.08 (s, 3H), 7.25 (d, J¼5.9 Hz, 2H), 7.46 (s, 2H),
7.69 (d, J¼7.8 Hz, 2H); 13C NMR (67.8 MHz, CDCl3)
d 26.6 (2C), 26.7
4.5.2. 2,7-Bis(3,3,4,4,5,5,6,6,7,7,8,8,8tridecafluorooctyl)-9H-fluorene
(6b). The same procedure employed above for compound 6a was
repeated using 5b (1.7 g, 2.0 mmol), Pd/C (11.8 mg, 0.1 mmol) and
THF/MeOH (40 mL, 1/1 v/v). The crude residue was concentrated to
give 6b (1.8 g, quant) as a pale yellow solid. The product was used in
the next reaction without further purification; mp 122e123 ꢀC; 1H
(2C), 50.2, 65.0, 108.1e120.2 (12C), 124.7 (2C), 127.8 (2C), 138.1 (2C),
140.0 (2C), 145.0 (4C); 19F NMR (466 MHz, CDCl3)
d
ꢁ80.9 (6F),
ꢁ114.7 (4F), ꢁ124.4 (4F), ꢁ125.9 (4F); IR (neat) 3367, 3006, 2970,
1472, 1423, 1367, 1317, 1184, 1140, 1095, 1071, 816, 732, 694,
648 cmꢁ1; HRMS [FABþ] m/z calcd for C30H19OF26 889.1022 found
889.1042.
NMR (270 MHz, CDCl3)
3.87 (s, 2H), 7.22 (d, J¼8.1 Hz, 2H), 7.40 (s, 2H), 7.70 (d, J¼7.8 Hz,
2H); 13C NMR (67.8 MHz, CDCl3)
26.6 (2C), 26.7 (2C), 36.7,
108.3e122.3 (12C), 125.0 (2C), 127.0 (2C), 137.7 (2C), 140.1 (2C),
143.9 (4C); 19F NMR (466 MHz, CDCl3)
ꢁ121.8 (4F), ꢁ122.7 (4F), ꢁ123.4 (4F), ꢁ126.0 (4F); IR (neat) 2948,
2927, 1466, 1367, 1319, 1229, 1183, 1142, 1073, 977, 828, 731,
694 cmꢁ1; HRMS [FABþ] m/z calcd for C29H17F26 859.0917 found
859.0916.
d 2.32e2.52 (m, 4H), 2.96e3.02 (m, 4H),
4.6.3. (2,7-Bis(3,3,4,4,5,5,5-heptafluoropentyl)-9H-fluoren-9-yl)
methanol (7c). The same procedure employed above for compound
7a was repeated using 6c (9.4 g, 17 mmol), dry Et2O (200 mL), NaH
(6.9 g, 171 mmol), HCO2Et (139 mL, 1.73 mol), NaBH4 (3.3 g,
87 mmol) and dry THF/dry MeOH (300 mL, 1/1 v/v). The crude
residue was purified by silica gel chromatography (EtOAc/
hexane¼1/5) to give 7c (8.7 g, 87%) as a pale yellow solid; mp
d
d
ꢁ80.6 (6F), ꢁ114.5 (4F),
112e113 ꢀC; 1H NMR (270 MHz, CDCl3)
d 2.32e2.52 (m, 4H),
2.97e3.03 (m, 4H), 4.08 (s, 3H), 7.25 (d, J¼6.8 Hz, 2H), 7.46 (s, 2H),
4.5.3. 2,7-Bis(3,3,4,4,5,5,5-heptafluoropentyl)-9H-fluorene (6c). The
same procedure employed above for compound 6a was repeated
using 5c (7.9 g, 14.0 mmol), Pd/C (84 mg, 0.7 mmol) and THF/MeOH
(200 mL, 1/1 v/v). The crude residue was concentrated to give 6c
(8.2 g, quant) as a pale yellow solid. The product was used in the
next reaction without further purification; mp 121e122 ꢀC; 1H NMR
7.69 (d, J¼7.8 Hz, 2H); 13C NMR (67.8 MHz, CDCl3)
d 26.58 (2C),
26.63 (2C), 50.2, 65.0, 108.6e121.1 (6C), 124.9 (2C), 127.8 (2C), 138.1
(2C), 140.0 (2C), 145.0 (2C); 19F NMR (466 MHz, CDCl3)
d
ꢁ80.4 (6F),
ꢁ115.6 (4F), ꢁ127.6 (4F); IR (neat) 3399, 3010, 2947, 1471, 1452,
1377, 1354, 1317, 1225, 1163, 1106, 1014, 911, 810, 743, 715 cmꢁ1
;
HRMS [FABþ] m/z calcd for C24H19OF14 589.1214 found 589.1257.
(270 MHz, CDCl3)
d 2.31e2.51 (m, 4H), 2.95e3.02 (m, 4H), 3.87 (s,
2H), 7.22 (d, J¼8.1 Hz, 2H), 7.39 (s, 2H), 7.70 (d, J¼7.8 Hz, 2H); 13C
4.7. A preparation of sodium salt of N-hydroxysuccinimide
(NaOSu)
NMR (67.8 MHz, CDCl3)
d
26.5 (2C), 26.6 (2C), 36.7, 108.7e121.6
(6C), 125.0 (2C), 137.7 (2C), 127.0 (2C), 140.1 (2C), 143.9 (4C); 19F
NMR (466 MHz, CDCl3)
d
ꢁ80.4 (6F), ꢁ115.5 (4F), ꢁ127.6 (4F); IR
NaOH (4.2 g, 0.11 mol) was added to a solution of N-hydrox-
ysuccinimide (10.0 g, 0.09 mol) in MeOH (64 mL) at room tem-
perature. The reaction mixture was stirred at room temperature for
24 h. The mixture was cooled to ꢁ20 ꢀC and filtered to give NaOSu
(7.1 g, 58%). The product was used immediately for the next step
without further purification.
(neat) 3008, 2971, 1472, 1422, 1357, 1211, 1169, 1130, 1086, 854, 819,
791, 743, 704 cmꢁ1; HRMS [FABþ] m/z calcd for C23H17F14 559.1108
found 559.1116.
4.6. A procedure for hydroxymethylation
4.6.1. (2,7-Bis(3,3,4,4,5,5,6,6,6-nonafluorohexyl)-9H-fluoren-9-yl)
methanol (7a). To a solution of 6a (18.5 g, 28.0 mmol) in dry Et2O
(500 mL) were added sodium hydride (NaH) (11.2 g, 279.0 mmol)
and ethyl formate (HCO2Et) (226 mL, 2.81 mol) slowly at 40 ꢀC and
then the reaction mixture was stirred for 1 h. The reaction was
quenched with 1.0 M HCl aq The organic layer was washed with
4.8. A procedure for fluorous-Fmoc reagent
4.8.1. Fluorous-Fmoc reagent (1a). To a solution of 7a (6.5 g,
9.4 mmol) and triphosgene (8.40 g, 28.3 mmol) in dry CH2Cl2
(300 mL) was added N,N-dimethylaniline (1.78 mL, 14.1 mmol) at
room temperature under N2. The reaction mixture was stirred at