N, O-ligand accelerated zinc-catalyzed transesterification of alcohols with vinyl esters

Article abstract of DOI:10.1016/j.jorganchem.2007.07.008

N-Phenyldiethanolamine (1f) is an efficient ligand for zinc-catalyzed transesterification of alcohols with vinyl acetate (R³ = Me) at room temperature. In the case of using other vinyl esters (R³ = Et, n-Pr, Ph), the corresponding products were easily obtained in the presence of pyridine-type ligand 2 instead of aminoalcohol 1f.

Full text of DOI:10.1016/j.jorganchem.2007.07.008

Journal of Organometallic Chemistry 692 (2007) 4389–4396
www.elsevier.com/locate/jorganchem
N,O-ligand accelerated zinc-catalyzed transesterification
of alcohols with vinyl esters
*
Takashi Mino , Tae Hasegawa, Yoshiaki Shirae, Masami Sakamoto, Tsutomu Fujita
Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
Received 13 June 2007; received in revised form 4 July 2007; accepted 10 July 2007
Available online 13 July 2007
Abstract
3
N-Phenyldiethanolamine (1f) is an efficient ligand for zinc-catalyzed transesterification of alcohols with vinyl acetate (R = Me) at
3
room temperature. In the case of using other vinyl esters (R = Et, n-Pr, Ph), the corresponding products were easily obtained in the
presence of pyridine-type ligand 2 instead of aminoalcohol 1f.
ꢀ
2007 Elsevier B.V. All rights reserved.
Keywords: Zinc catalyst; Alcohol; Ester; Transesterification
a : R1 = H, R2 = H
b : R = H, R = Me
OH
Ph
OH
Ph
1
. Introduction
OH
R1
OH
R1 c : R1 = H, R2 = Et
1
2
N
N
Ph
R1
Ph
R1
Transesterification is a convenient method for prepara-
R2
d : R = H, R2 = Bn
1
tion of versatile esters from inexpensive alcohols and esters
1]. Acidic [2] or basic [3] catalysts are commonly used to
1
2
e : R = Ph, R = Bn
1
2
f : R = H, R2 = Ph
1
[
promote this reaction in heating, but they sometimes exhi-
bit low chemoselectivity, and labile functional groups can
be damaged. They may also lead to the formation of side
products. Recently, the Nolan groups and the Hedrick
groups independently reported transesterification of alco-
hols using N-heterocyclic carbene type catalysts [4]. In this
case, not only vinyl esters but also alkyl esters such as ethyl
acetate and methyl benzoate were effective acylation
reagents at room temperature. On the other hand, organo-
2. Results and discussion
We investigated the effect of ligands for the zinc-pro-
moted transesterification of benzyl alcohol with vinyl
acetate in toluene as a solvent at room temperature
(Table 1). Without a ligand and Et Zn, the reaction did
not occur (Entry 1). Using Et Zn as a catalyst, the reaction
occurred, but we obtained benzyl acetate in a low yield
(Entry 2). We next investigated effect of ligands 1 and 2.
The zinc complex from 5 mol% of ligand and 10 mol% of
2
2
ꢀ
metallic catalysts such as Cp SmðthfÞ [5] distannoxanes
2
2
[
6], and tin(IV) amide with fluorous tag [7], or the basic imi-
nophosphoranes [8], iodine [9], ammonium triflate deriva-
tives [10] are better than simple acids, however they still
require heating conditions or long times to complete the
reaction. We report here an efficient method of transesteri-
Et Zn was used as a catalyst. Using ligands 1a–c led to
2
lower yields compared to the case without ligands (Entry
2 vs. Entries 3–5). N-benzyldiethanolamine (1d), its deriva-
tive 1e and pyridine-type ligand 2 led to moderate yields
(Entries 6, 7 and 9). When N-phenyldiethanolamine (1f)
was employed, the reaction yielded the desired product
quantitatively in 1 h (Entry 8).
fication using Et Zn with 1 or 2 as ligands with vinyl esters
2
as acylation reagents under mild conditions [11].
*
In the presence of 1f as a ligand, the effect of sol-
vents was examined. Using hexane as a solvent, instead
Corresponding author. Tel.: +81 43 290 3385; fax: +81 43 290 3401.
E-mail address: tmino@faculty.chiba-u.jp (T. Mino).
0
022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.07.008

4390
T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
Table 1
(Entry 14). There was no side product but the reaction
required much a longer reaction time.
Based on the result of the acylation of various primary
alcohols with vinyl acetate, we tested the transesterification
of steric hindered secondary alcohols with vinyl acetate
Optimization of reaction conditions on the transesterification of benzyl
alcohol with vinyl acetate
a
Et Zn
2
ligand
OH
OAc
+
OAc
solv., rt, 1 h
(Table 3). In the presence of 10 mol% of 1f and 20 mol%
3
a
of Et Zn at room temperature, benzylic secondary alco-
2
b
Entry
Ligand (mol%)
mol% of Et
2
Zn
Solvent
Yield (%)
hols, such as 1-phenylethanol and 1-(2-naphthyl)ethanol,
produced moderate to good yields (Entries 1 and 2). Allylic
secondary alcohol such as trans-piperitol and saturated sec-
ondary alcohols such as borneol and menthol also led to
good yields in the presence of 20 mol% of 1f and
1
2
3
4
5
6
7
8
9
–
–
–
10
10
10
10
10
10
10
10
10
10
10
10
10
PhMe
PhMe
PhMe
PhMe
PhMe
PhMe
PhMe
PhMe
PhMe
Hexane
THF
0
30
4
8
16
46
52
99 (90)
1a (5)
1b (5)
1c (5)
1d (5)
1e (5)
1f (5)
2 (5)
1f (5)
1f (5)
1f (5)
1f (5)
1f (5)
4
0 mol% of Et Zn (Entries 3–5). When pyridine-type ligand
2
2 was used, the desired product obtained in moderate yield
(Entry 6).
We next attempted esterification with other vinyl esters
such as vinyl propionate, butyrate, and benzoate [12]
c
c
(76)
10
11
12
13
14
a
81
27
7
16
1
(Table 4). In the case of vinyl propionate, the benzyl esters
MeCN
AcOEt
were obtained low yield using 5 mol% of 1f and 10 mol% of
CHCl
3
Et Zn (Entry 1). When the reaction was carried out in the
2
presence of pyridine-type ligand 2 instead of aminoalcohol
1f, the corresponding product was obtained in good yield
2
Reaction conditions: PhCH OH (1 mmol), vinyl acetate (5 mmol),
2
ligand, Et Zn in hexane (1.0 M), solvent (2 mL).
b
1
Determined by H NMR.
Values in parenthesis are isolated yields.
(Entry 2). Under this condition, other benzyl esters and
c
cinnamyl esters were easily prepared in good yields.
(Entries 3–7).
In summary, we found that various esters were easily
of toluene, led to also good yield (Entry 8 vs. Entry 10).
By contrast, polar solvents such as THF, acetonitrile,
ethyl acetate, and chloroform were less effective (Entries
obtained from alcohols and vinyl esters in the presence of
catalytic amount of Et Zn with 1f or 2 as a ligand at room
2
temperature.
1
1–14). Thus, non-polar solvents were more suitable for
this reaction.
3. Experimental
3.1. General methods
Under optimized reaction conditions, transesterifica-
tions of vinyl acetate with various primary alcohols bearing
a variety of functional groups were carried out at room
temperature, and the results are summarized in Table 2.
All the experiments were carried out under an argon
atmosphere. NMR spectra were recorded on a Bruker
DPX-300 spectrometer. Chemical shifts are reported in d
4
-Methoxybenzyl alcohol and 4-chlorobenzyl alcohol
were smoothly converted into the corresponding acetates
Entries 1 and 2). The reaction of the benzylic alcohol
1
(
ppm referenced to an internal SiMe standard for
H
4
1
3
with ester moiety in its molecule required a longer reac-
tion time, but no side product was identified (Entry 3).
This means that the methyl ester moiety is less reactive
compared to the vinyl acetate and does not take part in
the transesterification. ortho-, meta-, and para-methylben-
zyl alcohols were also treated with vinyl acetate, which
led to high yields. No steric effect was observed, nor
did any electronic influence result from the difference of
the position of the methyl group (Entries 4–6). 1-Naph-
thalenemethanol was also easily acylated into the desired
ester (Entry 7). Allylic alcohols such as cinnamyl alcohol
and geraniol also led to good yields (Entries 8 and 9).
Phenethyl alcohol, 2-phenyl-1-propanol, and 3-phenyl-1-
propanol reacted equally well, giving the corresponding
acetates in good yields (Entries 10–12). Saturated linear
alcohol such as decanol, was effectively acylated in a high
yield (Entry 13). The transesterification of alcohols bear-
ing acid-sensitive functional groups, such as 2-hydroxy-
methyl-1,4-benzodioxane, led to the desired products
and
C NMR. Mass spectra were recorded on a
GCMS-QP 5050, JEOL JMS-AX500, or JEOL JMS-
HX110. 1a–c and 1f are commercially available. 1d [13]
and 2 [14] were similarly prepared according to the litera-
ture methods.
3.2. Preparation of aminoalcohol 1e
A solution of phenylmagnesium bromide (30 mmol) in
THF (23 mL) was added to diethyl N-benzyliminodiacetate
(1.53 g, 6.0 mmol) in THF (15 mL) at room temperature.
The mixture was stirred for overnight. The mixture was
added sat. NH Cl aq. and diluted with ethyl acetate. The
4
organic layer was washed with brine, dried over MgSO4,
and concentrated under reduced pressure. The crude prod-
uct was purified by recrystallization from hexane–chloro-
form: 0.298 g, 0.60 mmol, 10% as a white solid; m.p.
1
147–150 ꢁC; H NMR (DMSO-d) d: 3.26 (s, 2H), 3.43 (s,
4H), 5.87 (s, 2H), 6.75–6.85 (m, 2H), 7.09–7.33 (m, 23H);

T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
4391
Table 2
Transesterification of primary alcohols with vinyl acetate
a
b
Entry
1
Alcohol
Time (h)
3
Product
Yield (%)
78
OH
OAc
MeO
MeO
3b
2
2
24
3
90
64
87
88
OH
OAc
Cl
Cl
3
c
c
3
OH
OAc
MeOOC
MeOOC
3d
4
5
OH
OAc
Me
Me
3
e
3
OH
OH
OAc
Me
Me
3
f
6
7
3
92
97
OAc
Me
Me
g
3
2.5
OH
OAc
3
h
8
5
4
95
97
Ph
OH
Ph
OAc
3
i
c
9
OH
OAc
3j
10
4
96
OH
OAc
Ph
Ph
3k
(
continued on next page)

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T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
Table 2 (continued)
b
Entry
Alcohol
Time (h)
5
Product
Yield (%)
91
11
OH
OAc
Ph
Ph
3
l
1
2
6
5
90
97
Ph
OH
Ph
OAc
3
m
c
13
8
8
OH
OAc
3n
14
24
79
O
O
O
O
OH
OAc
3o
a
2
Reaction conditions: alcohol (1 mmol), vinyl acetate (5 mmol), ligand 1f (5 mol%), Et Zn (10 mol%) in hexane (1.0 M, 0.1 mL), PhMe (2 mL), rt.
Isolated yields.
b
c
1
0 mol% of 1f and 20 mol% of Et
2
Zn were used under 0.5 mmol scale reaction.
Table 3
Transesterification of secondary alcohols with vinyl acetate
a
b
Entry
1
Alcohol
Ligand 1f/Et
2
Zn (mol%)
Product
Yield (%)
71
10/20
OH
OAc
3
p
2
3
10/20
20/40
85
79
OH
OAc
3
q
OH
OAc
OAc
3
r
4
5
20/40
20/40
86
OH
3
s
91
73
c
6
OH
OAc
3
t
a
Reaction conditions: alcohol (1 mmol), vinyl acetate (5 mmol), ligand 1f, Et
Isolated yields.
This reaction was carried out using 2 instead of 1f.
2
Zn in hexane (1.0 M), PhMe (2 mL), rt, 24 h.
b
c

T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
4393
Table 4
Transesterification of alcohols with vinyl esters
a
b
Entry
Alcohol
Vinyl ester
Ligand
Time (h)
Product
Yield (%)
c
1
2
1f
2
3
2.5
47
OH
O
O
O
90
O
Et
O
O
Et
4
5
3
4
O
O
2
2.5
88
nPr
nPr
O
2
5
O
92
O
Ph
O
Ph
6
5
6
O
O
O
3
3
4
O
90
94
92
O
O
O
Et
nPr
Ph
Ph
Ph
Ph
O
Et
7
2
O
O
Ph
OH
O
nPr
8
7
O
Ph
9
a
Reaction conditions: alcohol (1 mmol), vinyl acetate (5 mmol), ligand (5 mol%), Et
Isolated yields.
Determined by H NMR.
2
Zn (10 mol%) in hexane (1.0 M, 0.1 mL), PhMe (2 mL), rt.
b
c
1
1
3
C NMR (DMSO-d) d: 59.4, 64.9, 77.0, 126.5, 126.7,
was washed with brine, dried over MgSO , and concen-
4
1
27.1, 128.1, 128.4, 129.3, 139.1, 147.6; FAB-MS m/z
trated under reduced pressure. The residue was purified
by silica gel chromatography.
+
(
rel. intensity) 500 (M +1, 43); HRMS (FAB-MS) m/z.
Calc. for C H O N+H 500.2590. Found 500.2623.
3
5
34
2
3
.3.1. Benzyl acetate (3a) [15]
1
3.3. General procedure of transesterification of alcohol with
vinyl ester
90% as a colorless liquid; H NMR (CDCl ) d: 2.08 (s,
3
1
3
3H), 5.09 (s, 2H), 7.25–7.39 (m, 5H); C NMR (CDCl3)
d: 20.7, 66.0, 128.02, 128.05, 128.3, 135.8, 170.6; EI-MS
+
Under an atmosphere of argon, Et Zn (0.1 mmol) in
m/z (rel. intensity) 150 (M , 35).
2
hexane (1.0 M, 0.1 mL) was added to the solution of ligand
1
or 2 (0.05 mmol) in PhMe (1 mL) and the mixture was
stirred for 0.5 h at room temperature. A mixture of alcohol
1 mmol) and vinyl ester (5 mmol) in PhMe (1 mL) was
3.3.2. 4-Methoxybenzyl acetate (3b) [16]
1
78% as a colorless liquid; H NMR (CDCl ) d: 2.07 (s,
3
(
3H), 3.80 (s, 3H), 5.04 (s, 2H), 6.83–6.94 (m, 2H), 7.22–
1
3
added to the reaction mixture. After being stirred for cor-
responding period, the reaction mixture was diluted with
diethyl ether and quenched with water. The organic layer
7.34 (m, 2H); C NMR (CDCl ) d: 21.1, 55.3, 66.1,
3
114.0, 128.1, 130.2, 159.7, 171.0; EI-MS m/z (rel. intensity)
+
180 (M , 43).

4394
T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
3
.3.3. 4-Chlorobenzyl acetate (3c) [17]
1
3.3.11. Phenethyl acetate (3k) [15]
1
9
0% as a colorless liquid; H NMR (CDCl ) d: 2.10
96% as a colorless liquid; H NMR (CDCl ) d: 2.01
3
3
1
3
(
s, 3H), 5.06 (s, 2H), 7.23–7.38 (m, 4H); C NMR (CDCl3)
(s, 3H), 2.92 (t, J = 7.1 Hz, 3H), 4.26 (t, J = 7.1 Hz, 2H),
1
3
d: 21.0, 65.4, 128.7, 129.6, 134.1, 134.4, 170.7; EI-MS m/z
7.08–7.36 (m, 5H); C NMR (CDCl ) d: 21.0, 35.1, 64.9,
3
+
(
rel. intensity) 184 (M , 31).
126.6, 128.5, 128.9, 137.8, 171.0; EI-MS m/z (rel. intensity)
+
1
65 (M +1, 0.03).
3
.3.4. Methyl 4-(acetoxymethyl)benzoate (3d)
1
6
4% as colorless liquid; H NMR (CDCl ) d: 2.13 (s, 3H),
3.3.12. 2-Phenylpropyl acetate (3l) [22]
1
3
3
.92 (s, 3H), 5.15 (s, 2H), 7.41 (d, J = 8.2 Hz, 2H), 8.03 (dd,
91% as a colorless liquid; H NMR (CDCl ) d: 1.30
3
1
3
J = 1.7 and 6.6 Hz, 2H); C NMR (CDCl ) d: 23.2, 54.5,
6
m/z (rel. intensity) 209 (M +1, 100); HRMS (FAB-MS)
m/z. Calc. for C H O +H 209.0814. Found 209.0824.
(d, J = 7.0 Hz, 3H), 2.00 (s, 3H), 3.09 (sextet, J = 7.0 Hz,
1H), 4.04–4.21 (m, 2H), 7.10–7.39 (m, 5H); C NMR
3
1
3
7.8, 130.0, 132.18, 132.23, 143.3, 169.0, 173.0; FAB-MS
+
(CDCl ) d: 18.1, 20.9, 38.9, 69.4, 126.7, 127.3, 128.5,
3
+
143.2, 171.1; EI-MS m/z (rel. intensity) 178 (M , 22).
1
1
12
4
3
.3.5. 4-Methybenzyl acetate (3e) [18]
1
3.3.13. 3-Phenylpropyl acetate (3m) [23]
1
8
7% as a colorless liquid; H NMR (CDCl ) d: 2.08
90% as a colorless liquid; H NMR (CDCl ) d: 1.88–2.02
3
3
(
2
2
s, 3H), 2.34 (s, 3H), 5.06 (s, 2H), 7.16 (d, J = 8.0 Hz,
(m, 2H), 2.05 (s, 3H), 2.63–2.74 (m, 2H), 4.10 (q,
1
3
H), 7.24 (d, J = 8.0 Hz, 2H); C NMR (CDCl ) d :
J = 6.6 Hz, 2H), 7.11–7.23 (m, 3H), 7.23–7.34 (m, 2H);
3
1
3
1.0, 21.2, 66.3, 128.5, 129.3, 132.9, 138.1, 170.9; EI-MS
C NMR (CDCl ) d: 21.0, 30.2, 32.2, 63.8, 126.0, 128.4,
3
+
+
m/z (rel. intensity) 164 (M , 50).
128.4, 141.2, 171.2; EI-MS m/z (rel. intensity) 178 (M ,
.11).
0
3
.3.6. 3-Methybenzyl acetate (3f) [19]
1
8
8% as a colorless liquid; H NMR (CDCl ) d: 2.09
3.3.14. Decyl acetate (3n) [24]
3
1
3
1
(
s, 3H), 2.35 (s, 3H), 5.06 (s, 2H), 7.07–7.31 (m, 4H);
C
97% as a colorless liquid; H NMR (CDCl ) d: 0.88
3
NMR (CDCl ) d: 21.0, 21.4, 66.4, 125.4, 128.5, 129.0
(t, J = 6.8 Hz, 3H), 1.18–1.41 (m, 14H), 1.62 (quintet,
3
(
1
C · 2), 135.8, 138.3, 170.9; EI-MS m/z (rel. intensity)
J = 7.0 Hz, 2H), 2.05 (s, 3H), 4.05 (t, J = 6.8 Hz, 2H) ;
+
13
64 (M , 39).
C NMR (CDCl ) d: 14.5, 21.4, 23.1, 26.3, 29.0, 29.66,
3
2
9.71, 29.9, 32.3, 65.1, 171.7; EI-MS m/z (rel. intensity)
+
3
.3.7. 2-Methybenzyl acetate (3g) [20]
1
201 (M +1, 1).
9
2% as a colorless liquid; H NMR (CDCl ) d: 2.09
3
1
3
(
s, 3H), 2.35 (s, 3H), 5.12 (s, 2H), 7.12–7.39 (m, 4H);
C
3.3.15. 2-Acetoxymethyl-1,4-benzodioxane (3o) [25]
1
NMR (CDCl ) d: 18.9, 21.0, 64.7, 126.0, 128.6, 129.2,
79% as a yellow liquid; H NMR (CDCl ) d: 2.07
3
3
1
30.4, 133.8, 137.0, 171.0; EI-MS m/z (rel. intensity) 164
(s, 3H), 4.01 (dd, J = 6.8 and 11.4 Hz, 1H), 4.17–4.42 (m,
+
13
(
M , 0.7).
4H), 6.67–6.95 (m, 4H) ; C NMR (CDCl ) d: 20.8, 62.6,
3
6
5.1, 70.9, 117.3, 117.5, 121.7, 142.8, 143.0, 170.6; EI-MS
+
3
.3.8. (1-Naphthalenyl)methyl acetate (3h) [21]
1
m/z (rel. intensity) 208 (M , 37).
9
7% as a colorless liquid; H NMR (CDCl ) d: 2.10
3
(
s, 3H), 5.56 (s, 2H), 7.42–7.60 (m, 4H), 7.78–7.92 (m,
3.3.16. 1-Phenylethyl acetate (3p) [15]
1
1
3
2
1
1
H), 7.95–8.05 (m, 1H); C NMR (CDCl ) d: 21.1, 64.6,
71% as a colorless liquid; H NMR (CDCl ) d: 1.53
3
3
23.6, 125.3, 126.0, 126.6, 127.5, 128.8, 129.4, 131.5,
(d, J = 6.6 Hz, 3H), 2.06 (s, 3H), 5.88 (q, J = 6.6 Hz,
+
13
31.6, 133.8, 171.0; EI-MS m/z (rel. intensity) 200 (M , 60).
1H), 7.21–7.42 (m, 5H); C NMR (CDCl ) d: 21.3, 22.2,
3
7
2.3, 126.1, 127.9, 128.5, 141.7, 170.3; EI-MS m/z (rel.
+
3
.3.9. Cinnamyl acetate (3i) [15]
1
intensity) 164 (M , 24).
9
6% as a colorless liquid; H NMR (CDCl ) d: 2.03
3
(
s, 3H), 4.66 (dd, J = 1.2 and 6.5 Hz, 2H), 6.22 (td, J =
3.3.17. 1-(2-Naphthyl)ethyl acetate (3q) [26]
1
6
7
1
.5 and 15.9 Hz, 1H), 6.58 (d, J = 15.9 Hz, 1H), 7.11–
85% as a colorless liquid; H NMR (CDCl ) d: 1.62
3
1
3
.39 (m, 5H); C NMR (CDCl ) d: 21.0, 65.1, 123.1,
(d, J = 6.6 Hz, 3H), 2.09 (s, 3H), 6.05 (q, J = 6.6 Hz,
1H), 7.41–7.53 (m, 3H), 7.71–7.92 (m, 4H); C NMR
3
1
3
26.6, 128.1, 128.6, 134.2, 136.2, 170.8; FAB-MS m/z
+
(
rel. intensity) 176 (M , 32).
(CDCl ) d: 21.4, 22.2, 72.4, 124.1, 125.0, 126.0, 126.2,
3
1
27.7, 128.0, 128.4, 133.0, 133.2, 139.0, 170.4; EI-MS m/z
+
3
.3.10. Geranyl acetate (3j) [15]
1
(rel. intensity) 214 (M , 25).
9
7% as a colorless liquid; H NMR (CDCl ) d: 1.60
3
(
(
5
2
s, 3H), 1.68 (s, 3H), 1.71 (s, 3H), 1.99–2.17 (m, 4H), 2.06
3.3.18. trans-Piperityl acetate (3r) [27]
1
s, 3H), 4.72 (d, J = 7.1 Hz, 2H), 5.03–5.15 (m, 1H),
79% as a colorless liquid; H NMR (CDCl ) d: 0.84
3
1
3
.30–5.39 (m, 1H); C NMR (CDCl ) d: 16.4, 17.7, 21.0,
(d, J = 6.9 Hz, 3H), 0.95 (d, J = 6.9 Hz, 3H), 1.33–1.56
3
5.7, 26.3, 39.5, 61.4, 118.2, 123.7, 131.8, 142.2, 171.1;
(m, 2H), 1.63–1.80 (m, 5H), 1.92–2.02 (m, 2H), 2.06
+
13
EI-MS m/z (rel. intensity) 196 (M , 0.08).
(s, 3H), 5.21–5.36 (m, 2H); C NMR (CDCl ) d: 17.9,
3

T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
4395
2
1
0.9, 21.1, 21.5, 23.2, 26.8, 29.5, 43.9, 72.1, 120.8, 139.8,
71.2; EI-MS m/z (rel. intensity) 196 (M , 2).
123.8, 127.0, 128.4, 129.0, 134.5, 136.7, 173.8; EI-MS m/z
(rel. intensity) 204 (M , 13).
+
+
3
.3.19. Bornyl acetate (3s) [15]
1
3.3.26. Cinnamyl benzoate (9) [31]
1
8
6% as a colorless liquid; H NMR (CDCl ) d: 0.83
92% as a colorless liquid; H NMR (CDCl ) d: 4.98
3
3
(
1
1
s, 3H), 0.87 (s, 3H), 0.90 (s, 3H), 0.97 (dd, J = 3.5 and
(dd, J = 1.2 and 6.4 Hz, 2H), 6.40 (td, J = 6.4 and 15.9 Hz,
1H), 6.74 (d, J = 15.9 Hz, 1H), 7.20–7.37 (m, 3H), 7.38–
3.7 Hz, 1H), 1.16–1.38 (m, 2H), 1.61–1.82 (m, 2H),
.86–2.00 (m, 1H), 2.06 (s, 3H), 2.28–2.42 (m, 1H), 4.88
1
3
7.50 (m, 4H), 7.51–7.61 (m, 1H), 8.04–8.13 (m, 2H);
C
1
3
(
ddd, J = 1.3, 5.6 and 10.0 Hz, 1H); C NMR (CDCl3)
NMR (CDCl ) d: 65.6, 123.3, 126.7, 128.1, 128.4, 128.6,
3
d: 13.4, 18.8, 19.6, 21.2, 27.0, 28.0, 36.7, 44.8, 47.7, 48.6,
129.7, 130.2, 133.0, 134.3, 136.2, 166.4; EI-MS m/z (rel.
intensity) 238 (M , 5).
+
+
7
9.8, 171.4; EI-MS m/z (rel. intensity) 196 (M , 1.5).
3
.3.20. Mentyl acetate (3t) [15]
1
References
9
1% as a colorless liquid; H NMR (CDCl ) d: 0.76
3
(
2
1
d, J = 7.0 Hz, 3H), 0.82–1.15 (m, 9H), 1.21–1.59 (m,
[
[
1] (a) J. Otera, Chem. Rev. 93 (1993) 1449–1470;
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H), 1.60–1.75 (m, 2H), 1.79–1.93 (m, 1H), 1.94–2.11 (m,
(
1
3
H), 2.03 (s, 3H), 4.68 (td, J = 4.4 and 10.9 Hz, 1H);
C
NMR (CDCl ) d: 16.3, 20.6, 21.2, 21.9, 23.4, 26.2, 31.3,
3
1
3
4.2, 30.9, 46.9, 74.1, 170.6; EI-MS m/z (rel. intensity)
(
b) D. Seebach, E. Hungerb u¨ hler, R. Naef, P. Schnurrenberger, B.
Weidmann, M. Z u¨ ger, Synthesis (1982) 138–140;
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c) E. Vedejs, N.S. Bennett, L.M. Conn, S.T. Diver, M. Gringras, S.
+
99 (M +1, 0.01).
(
3
.3.21. Benzyl propanoate (4) [28]
1
(
1
(
9
0% as a colorless liquid; H NMR (CDCl ) d: 1.16
3
(
7
1
t, J = 7.5 Hz, 3H), 2.38 (q, J = 7.6 Hz, 2H), 5.12 (s, 2H),
1
3
.26–7.42 (m, 5H); C NMR (CDCl ) d: 9.5, 28.0, 66.6,
3
Lin, P.A. Oliver, M.J. Peterson, J. Org. Chem. 58 (1993) 7286–7288.
4] (a) G.A. Grasa, R.M. Kissling, S.P. Nolan, Org. Lett. 4 (2002) 3583–
3586;
28.6, 129.0, 136.5, 174.7; EI-MS m/z (rel. intensity) 164
[
+
(
M , 23).
(
b) G.W. Nyce, J.A. Lamboy, E.F. Connor, R.M. Waymouth, J.L.
Hedrick, Org. Lett. 4 (2002) 3587–3590;
3
.3.22. Benzyl butanoate (5) [15]
1
(
(
(
c) G.A. Grasa, T. G u¨ veli, R. Singh, S.P. Nolan, J. Org. Chem. 68
2003) 2812–2819;
d) R. Singh, R.M. Kissling, M. Letellier, S.P. Nolan, J. Org. Chem.
8
8% as a colorless liquid; H NMR (CDCl ) d: 0.94
3
(
t, J = 7.4 Hz, 3H), 1.67 (sextet, J = 7.4 Hz, 2H), 2.33
1
3
(
t, J = 7.4 Hz, 2H), 5.11 (s, 2H), 7.27–7.40 (m, 5H);
C
69 (2004) 209–212.
5] Y. Ishii, M. Takeno, Y. Kawasaki, A. Muromachi, Y. Nishiyama, S.
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7] X. Hao, A. Yoshida, J. Nishikido, Tetrahedron Lett. 45 (2004) 781–
[
NMR (CDCl ) d: 14.1, 18.9, 36.6, 66.5, 128.6, 129.0,
1
3
+
36.6, 173.9; EI-MS m/z (rel. intensity) 178 (M , 23).
[
[
3
.3.23. Benzyl benzoate (6) [15]
1
7
85.
9
2% as a colorless liquid; H NMR (CDCl ) d: 5.36
[8] P. Ilankumaran, J.G. Verkade, J. Org. Chem. 64 (1999) 9063–9066.
9] K. Ramalinga, P. Vijayalakshmi, T.N.B. Kaimal, Tetrahedron Lett.
3
[
(
(
s, 2H), 7.29–7.49 (m, 7H), 7.50–7.60 (m, 1H), 8.02–8.13
m, 2H); C NMR (CDCl ) d: 66.7, 128.2, 128.3, 128.4,
1
3
43 (2002) 879–882.
3
[
[
[
10] T. Funatomi, K. Wakasugi, T. Misaki, Y. Tanabe, Green Chem. 8
2006) 1022–1027.
1
28.7, 129.8, 130.2, 133.1, 136.1, 166.5; EI-MS m/z (rel.
(
+
intensity) 212 (M , 21).
11] Preliminary communication: Y. Shirae, T. Mino, T. Hasegawa, M.
Sakamoto, T. Fujita, Tetrahedron Lett. 46 (2005) 5877–5879.
12] Recently zinc catalyzed asymmetric benzoation of meso-diol with
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4282–4372.
3
.3.24. Cinnamyl propanoate (7) [29]
1
9
0% as a colorless liquid; H NMR (CDCl ) d: 1.17
3
(
t, J = 7.5 Hz, 3H), 2.38 (q, J = 7.6 Hz, 2H), 4.73 (dd,
[
[
[
J = 1.1 and 6.4 Hz, 2H), 6.29 (td, J = 6.4 and 15.9 Hz,
1
NMR (CDCl ) d: 9.5, 28.0, 65.3, 123.8, 127.0, 128.5,
1
3
H), 6.65 (d, J = 15.9 Hz, 1H), 7.17–7.44 (m, 5H);
C
14] E. Gomez, R. Flores, G. Huerta, C. Alvarez-Toledano, R.A.
Toscano, V. Santes, N. Nava, P. Sharma, J. Organomet. Chem. 672
3
1
29.0, 134.5, 136.7, 174.7; EI-MS m/z (rel. intensity) 190
(
2003) 115–122.
+
(
M , 14).
1
13
15] C.J. Pouchert, J. Behnke, The Aldrich Library of H and C FT
NMR spectra.
3
.3.25. Cinnamyl butanoate (8) [30]
1
[16] A.K. Chakraborti, L. Sharma, R. Gulhane, R. Shivani, Tetrahedron
9 (2003) 7661–7668.
5
9
4% as a colorless liquid; H NMR (CDCl ) d: 0.97
3
[
[
[
[
17] J.W. Bosco, A.K. Saikia, Chem. Commun. (2004) 1116–1117.
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Tetrahedron 59 (2003) 10147–10152.
(
7
t, J = 7.4 Hz, 3H), 1.57–1.78 (m, 2H), 2.33 (t, J =
.4 Hz, 2H), 4.73 (d, J = 6.4 Hz, 2H), 6.28 (td, J = 6.4
and 15.9 Hz, 1H), 6.64 (d, J = 15.9 Hz, 1H), 7.19–7.46
1
3
(
m, 5H); C NMR (CDCl ) d: 14.1, 18.9, 36.6, 65.2,
3

4396
T. Mino et al. / Journal of Organometallic Chemistry 692 (2007) 4389–4396
[
[
[
21] B. Shi, R.D. Guthrie, J. Org. Chem. 58 (1993) 3067–3071.
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48 (1983) 3876–3883.
1
13
[
[
[
25] B.A. D’Sa, J.G. Verkade, J. Org. Chem. 61 (1996) 2963–2966.
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