AMIN Rostami et al. / Chinese Journal of Catalysis, 2011, 32: 60–64
Alcohol (1 mmol) was added to a mixture of Fe(NO3)3·9H2O
71.45; H, 10.72. MS (m/z): 180 [M+].
(0.1 mmol), NaI (0.2 mmol), and HCOOH (20 mmol). The
mixture was stirred vigorously at room temperature for a spe-
cific time. After completion of the reaction, the sample was
treated as described in section 1.1.
2-Adamantanyl formate (11). IR (KBr, cmꢀ1): v 2940, 2864,
1
1725, 1471, 1183. H NMR (90 MHz, CDCl3): į 0.82–1.45
(complex, 14H), 4.93 (m, 1H), 7.97(s, 1H). Anal. Calcd. for
C11H16O2: C, 73.30; H, 8.95; O, 17.756. Found: C, 73.12; H,
9.0. MS (m/z): 180 [M+].
1.3 Spectral data of some known formates
2-Heptanyl formate (12). IR (Neat, cmꢀ1): v 2959, 2872,
1731, 1456, 1378. 1H NMR (90 MHz, CDCl3): į 0.80–1.12 (m,
14H), 4.91 (m, 1H), 7.95 (s, 1H). Anal. Calcd. for C8H16O2: C,
66.63; H, 11.18; O, 22.19. Found: C, 66.80; H, 11.28. MS
(m/z): 144 [M+].
4-Chlorobenzyl formate (1). IR (Nujol, cmꢀ1): v 3037, 2933,
1
1725, 1450. H NMR (90 MHz, CDCl3): į 5.12 (s, 2H), 7.30
(m, 4H), 8.15 (s, 1H). Anal. Calcd. for C8H7ClO2: C, 56.32; H,
4.14; Cl, 20.78; O, 18.76. Found: C, 56.57; H, 4.10. MS (m/z):
170 [M+].
1-Adamantanyl formate (14). IR (KBr, cmꢀ1): v 2940, 2985,
1
1750, 1485, 1135. H NMR (90 MHz, CDCl3): į 1.61–2.05
4-Nitrobenzyl formate (3). IR (KBr, cmꢀ1): v 3082, 2854,
1726, 1607, 1521, 1459, 1347, 1152, 846, 738. 1H NMR
(90MHz, CDCl3): į 5.27 (s, 2H), 7.46–7.54 (m, 2H), 8.15–8.24
(m, 3H). Anal. Calcd. for C8H7NO4: C, 53.04; H, 3.89; N, 7.73;
O, 35.33. Found: C, 53.21; H, 3.50; N, 7.48. MS (m/z): 181
[M+].
Cinnamyl formate (4). IR (Neat, cmꢀ1): v 3027, 2934, 2975,
1724, 1449, 1494, 1165. 1H NMR (90 MHz, CDCl3): į 4.82 (d,
2H), 6.23–6.68 (m, 2H), 7.25–7.40 (m, 5H), 8.12 (s, 1H). Anal.
Calcd. for C10H10O2: C, 74.06; H, 6.21; O, 19.73. Found: C,
73.96; H, 6.15. MS (m/z): 162 [M+].
(complex, 15H), 7.99 (s, 1H). Anal. Calcd. for C11H16O2: C,
73.30; H, 8.95; O, 17.756. Found: C, 73.62; H, 8.69. MS (m/z):
180 [M+].
1,4-Cyclohexanediyl diformate (16). IR (Nujol, cmꢀ1): v
1
2983, 2969, 1727, 1473, 1150. H NMR (90 MHz, CDCl3): į
1.52 (m, 4H), 1.80 (m, 4H), 4.85 (m, 2H), 8.04 (s, 2H). Anal.
Calcd. for C8H12O4: C, 55.81; H, 7.02; O, 37.17. Found: C,
55.85; H, 7.20. MS (m/z): 172 [M+].
2 Results and discussion
2-Phenylethyl formate (5). IR (Neat, cmꢀ1): v 3023, 2980,
2975, 1760, 1155. 1H NMR (90 MHz, CDCl3): į 2.9 (m, 2H),
4.40 (t, 2H), 7.3 (m, 5H), 8.01 (s, 1H). Anal. Calcd. for
C9H10O2: C, 71.98; H, 6.71; O, 21.31. Found: C, 72.07; H, 6.50.
MS (m/z): 150 [M+].
In recent years, molecular iodine has received considerable
attention as an inexpensive and readily available catalyst for
various organic transformations under very mild and conven-
ient conditions because it gives the corresponding products in
excellent yields with high selectivity. This is due to the oxi-
dizing ability and Lewis acidity of iodine [19]. As part of our
work on the catalytic application of reagents in the transfor-
mation of organic functional groups [20–24], we report here
the formylation of a wide range of alcohols using formic acid at
room temperature under solvent-free conditions in the presence
of a catalytic amount of molecular iodine.
Diphenylmethyl formate (6). IR (Neat, cmꢀ1): v 3032, 2930,
1
2854, 1731, 1495, 1456, 1157. H NMR (90 MHz, CDCl3): į
7.13 (s, 1H), 7.25–7.42 (m, 10H), 8.26 (s, 1H). Anal. Calcd. for
C14H12O2: C, 79.22; H, 5.70; O, 15.08. Found: C, 79.42; H,
5.80. MS (m/z): 212 [M+].
1-Phenylethyl formate (7). IR (Neat, cmꢀ1): v 3020, 2988,
2978, 1757, 1165. 1H NMR (90 MHz, CDCl3): į 1.53 (d, 3H),
5.97 (q, 1H), 7.34 (m, 5H), 8.06 (s, 1H). Anal. Calcd. for
C9H10O2: C, 71.98; H, 6.71; O, 21.31. Found: C, 71.75; H, 6.92.
MS (m/z): 150 [M+].
Cyclohexyl formate (8). IR (Nujol, cmꢀ1): v 2980, 2970,
1725, 1475, 1150. 1H NMR (90 MHz, CDCl3): į 0.95 (m, 4H),
1.22 (m, 4H), 1.67 (m, 2H), 4.82 (m, 1H), 8.02 (s, 1H). Anal.
Calcd. for C7H12O2: C, 65.60; H, 9.44; O, 24.97. Found: C,
65.35; H, 9.27. MS (m/z): 128 [M+].
We first optimized the reaction conditions by evaluating the
influence of different amounts of formic acid and catalyst on
the time and product yield in the formylation of benzhydrole,
which was used as a model. The results are shown in Table 1.
The optimum amount was 20 mmol of HCOOH in the pres-
ence of 0.1 mmol of I2, which gave the complete conversion
of benzhydrole to the corresponding formate ester.
Table 1 Optimization of amount of formic acid and iodine for the for-
Cyclododecanyl formate (9). IR (Neat, cmꢀ1): v 2940, 2864,
1725, 1471, 1183. 1H NMR (90 MHz, CDCl3): į 1.32–1.53 (m,
22H), 5.11 (b, 1H), 8.01 (s, 1H). Anal. Calcd. for C13H24O2: C,
73.54; H, 11.39; O, 15.07. Found: C, 73.75; H, 11.19. MS
(m/z): 212 [M+].
Methyl formate (10). IR (Neat, cmꢀ1): v 3058, 2959, 2872,
1723, 1456, 1191. 1H NMR (90 MHz, CDCl3): į 0.85–1.15 (m,
15H), 1.45–2.0 (m, 3H), 4.74 (m, 1H), 7.99 (s, 1H). Anal.
Calcd. for C11H20O2: C, 71.70; H, 10.94; O, 17.36. Found: C,
mylation of benzhydrole (1 mmol) at room temperature
HCOOH (mmol)
I2 (mmol)
0.1
Time (min)
Conversiona (%)
1
5
30
30
30
3
25
45
0.1
10
20
20
20
0.1
60
0.1
100
90
0.02
0.05
30
30
100
aDetermined by 1H NMR.