Polymer-supported sulfinimidoyl chlorides: A convenient reagent for oxidation of alcohols

Article abstract of DOI:10.1246/bcsj.76.1433

Two polymer-supported sulfinimidoyl chlorides, i.e., 4-(N-tert-butylchlorosulfinimidoyl)phenoxymethylpolystyrene (3) and 4-(N-tert-butylchlorosulfinimidoyl)polystyrene (10), were prepared from chloromethylpolystyrene and polystyrene, respectively. Stoichiometric or catalytic oxidation of various primary and secondary alcohols using these polymer-supported sulfinimidoyl chlorides proceeded smoothly, and the corresponding aldehydes and ketones were conveniently prepared in good-to-high yields by simple work-up procedures. The polymer-supported oxidant 10 was recycled repeatedly by chlorination of a used polymer 11 with N-chlorosuccinimide (NCS) after stoichiometric oxidation.

Full text of DOI:10.1246/bcsj.76.1433

Ó 2003 The Chemical Society of Japan
Bull. Chem. Soc. Jpn., 76, 1433–1440 (2003) 1433
Polymer-Supported Sulfinimidoyl Chlorides: A Convenient Reagent for
Oxidation of Alcohols
#
Jun-ichi Matsuo, Asahi Kawana, Hiroyuki Yamanaka, and Hiroaki Kamiyama
ꢀ;
Center for Basic Research, The Kitasato Institute, 6-15-5 (TCI), Toshima, Kita-ku, Tokyo 114-0003
(Received January 31, 2003)
Two polymer-supported sulfinimidoyl chlorides, i.e., 4-(N-tert-butylchlorosulfinimidoyl)phenoxymethylpolysty-
rene (3) and 4-(N-tert-butylchlorosulfinimidoyl)polystyrene (10), were prepared from chloromethylpolystyrene and
polystyrene, respectively. Stoichiometric or catalytic oxidation of various primary and secondary alcohols using these
polymer-supported sulfinimidoyl chlorides proceeded smoothly, and the corresponding aldehydes and ketones were
conveniently prepared in good-to-high yields by simple work-up procedures. The polymer-supported oxidant 10 was
recycled repeatedly by chlorination of a used polymer 11 with N-chlorosuccinimide (NCS) after stoichiometric oxida-
tion.
Two new methods were reported from our laboratory for
efficient and mild oxidation of primary and secondary alcohols
to the corresponding aldehydes and ketones by utilizing sulfi-
nimidoyl chloride as an oxidizing agent. The first one was
stoichiometric oxidation using N-tert-butylbenzenesulfinimi-
doyl chloride (1) and 1,8-diazabicyclo[5.4.0]undec-7-ene
(DBU). This oxidation smoothly oxidized various alcohols
to give carbonyl compounds in good-to-high yields along with
N-tert-butylbenzenesulfenamide (2) which was separated from
carbonyl compounds by silica gel chromatography or distilla-
tion (Scheme 1, reaction 1).1 The second method was the
sulfenamide 2-catalyzed oxidation of alcohols with a stoichio-
metric amount of N-chlorosuccinimide (NCS) in the coexis-
tence of potassium carbonate and molecular sieves 4A (MS4A)
(reaction 2).2 This catalytic oxidation proceeded quite effi-
ciently under mild conditions, and purification of the formed
carbonyl compounds was much easier compared to the 1-medi-
ated stoichiometric oxidation.
alcohols because sulfenamide formed from sulfinimidoyl
chloride after oxidation was easily and completely separated
just by filtration of the polymer reagent.3;4 In this article, we
would like to report more detailed results on preparation of
polymer-supported sulfinimidoyl chlorides and oxidation of
alcohols using them.5
Results and Discussion
Preparation of Polymer-Supported Sulfinimidoyl Chlo-
ride 3. Preparation of polymer-supported sulfinimidoyl chlo-
ride 3 which has a phenoxymethylene unit as a linker between
sulfinimidoyl chloride moiety and polystyrene core was first
planned considering its availability from chloromethyl-
polystyrene. The preparation of 3 is illustrated in Scheme 2:
that is, 4-(tritylsulfanyl)phenoxymethylpolystyrene (4) was
prepared in the first place by treating chloromethylpolystyrene
with sodium 4-(tritylsulfanyl)phenolate in DMF. The trityl
group of 4 was then deprotected with trifluoroacetic acid in
the presence of triethylsilane6 to afford 4-sulfanylphenoxy-
methylpolystyrene (5)7 in 67% yield in two steps. The loading
(0.59 mmol/g) of a benzenethiol unit in 5 was determined by
A polymer-supported sulfinimidoyl chloride was then con-
sidered to be useful for convenient and clean oxidation of
Scheme 1.
# Kitasato Institute for Life Sciences, Kitasato University,
5-9-1 Shirokane, Minato-ku, Tokyo 108-8641
Scheme 2.
Published on the web July 15, 2003; DOI 10.1246/bcsj.76.1433

1434 Bull. Chem. Soc. Jpn., 76, No. 7 (2003)
Polymer-Supported Sulfinimidoyl Chlorides
Table 1. Stoichiometric Oxidation of Various Alcohols to the Corresponding Carbonyl Compounds by Using Polymer-
Supported Sulfinimidoyl Chloride 3
Entry
1
Alcohol
Methoda)
A
Yield/%b)
98
Entry
8
Alcohol
Methoda)
B
Yield/%b)
89
2
3
4
A
A
A
58
9
B
85
10
11
A
B
50d)
92d)
84c)
72
12
13
B
B
81
5
A
89
81d)
6
7
A
A
80
90
14
15
B
B
76d)
97d)
a) Method A: a mixture of alcohol and i-Pr2NEt was added to the swelled polymer 3 in CH2Cl2 at ꢂ78 ꢁC, and then the
reaction mixture was stirred at ꢂ78 ꢁC for 30 min. Method B: alcohol was added to the swelled polymer 3 in CH2Cl2
at 0 ꢁC, followed by the addition of i-Pr2NEt at ꢂ78 ꢁC. The reaction mixture was stirred at ꢂ78 ꢁC–rt for 30 min. b)
Isolated yield unless otherwise noted. c) The stereoisomeric ratio (E=Z ¼ 96=4) did not change by the present
oxidation. d) Determined by GC-analysis using an internal standard.
isolating triphenylmethane which was formed in the above-
mentioned deprotection of the trityl group. The thiol group
was acetylated with acetyl chloride and pyridine to give 4-
(acetylsulfanyl)phenoxymethylpolystyrene (6) which con-
tained 0.43 mmol/g of an acetylsulfanyl group. The loading
of the acetylsulfanyl group was determined by isolating N-
benzylacetamide after heating 6 and benzylamine at 90 ꢁC
for 6 h. Finally, the desired polymer-supported sulfinimidoyl
chloride resin 3 was prepared by the reaction of 6 and N,N-
dichloro-tert-butylamine in refluxing benzene. The content of
sulfinimidoyl group (0.18 mmol/g) of 3 was determined by
detecting 4-methoxybenzyl chloride by GC-analysis after
treating 3 with 4-methoxybenzyl alcohol in CH2Cl2 at room
temperature for 2 h.8
Thus-prepared polymer-supported sulfinimidoyl chloride 3
showed no decline in activity when kept at room temperature
under an argon atmosphere for eight days while hydrolysis
took place rapidly when exposed to air. The hydrolysis of 3
was judged easily from the change in its color: from bright
yellow to white when hydrolyzed.9
Supported Sulfinimidoyl Chloride 3. First, when effects
of bases were examined in the oxidation of benzyl alcohol
by using 1.8 molar amounts of the polymer oxidant 3, i-Pr2NEt
was effective while DBU and K2CO3 were not. The use of
DBU or K2CO3 gave a substantial amount of benzyl chloride
together with the desired oxidation product, benzaldehyde.
In the oxidation of benzylic and allylic alcohols, a mixture
of an alcohol and i-Pr2NEt was added to the polymer 3 at ꢂ78
ꢁC, and ꢁan alcohol was smoothly oxidized in less than 30 min
at ꢂ78 C (Table 1, Method A, Entries 1–7). However, this
method gave the corresponding carbonyl compounds in low
yields in the oxidation of simple primary and secondary alco-
hols: for example, the oxidation of cyclohexanol gave cyclo-
hexanone in 50% yield (Entry 10). This result may be ex-
plained by the slow formation of alkyl sulfinimidate, an
important oxidation intermediate,1c from 3 and cyclohexanol.
Then, primary and secondary alcohols were mixed first with 3
at 0 ꢁC, and then i-Pr2NEt was added successively at ꢂ78 ꢁC.
The corresponding carbonyl compounds were obtained in good
yields when the reaction temperature was raised up to room
temperature (Method B, Entries 8–9, 11–15).
Stoichiometric Oxidation of Alcohols Using Poylmer-

J. Matsuo et al.
Bull. Chem. Soc. Jpn., 76, No. 7 (2003) 1435
Scheme 3.
Double bond isomerization was not observed in the present
oxidation using 3 and the protecting groups such as trityl and
tert-butyldiphenylsilyl groups were not damaged. However,
some alcohols such as 1,3-diphenylpropan-1-ol, diphenylme-
thanol, and 2-methylcyclohexan-1-ol were oxidized in moder-
ate yields (Entries 2, 4, and 14).
Scheme 5.
attached on a polystyrene core was next planned on the con-
sideration that sulfenamide 11, a reduced product of 10, would
be more stable than 9 (Scheme 4, reaction 2).
Preparation of a new polymer-supported sulfinimidoyl
chloride resin 10 is shown in Scheme 5. 4-Sulfanylpolysty-
Oxidation of primary alcohols to the corresponding alde-
hydes, and the successive carbon–carbon bond formation with
carbon nucleophiles are often employed in the construction of
a carbon skeleton. In order to exemplify the usefulness of the
polymer reagent 3, two-step reactions which consisted of the
3-mediated oxidation of a primary alcohol and a Lewis acid-
catalyzed aldol reaction of thus-formed aldehyde with silyl
enol ether10 were tried (Scheme 3). The oxidation of 4-nitro-
benzyl alcohol with 3 rapidly gave 4-nitrobenzaldehyde after
silica gel filtration which removed the used resin and i-Pr2NEt.
The obtained aldehyde was then treated with trimethylsilyl
11
´
rene (13) was prepared according to Frechet’s method: that
is, cross-linked polystyrene was directly lithiated by using n-
BuLi and N,N,N0,N0-tetramethylethylenediamine (TMEDA),
and the lithiated polystyrene was then treated with sulfur.
The S–S bonds in sulfurized polystyrene 12 were cleaved by
reduction with two molar amounts of LiAlH4 to afford 4-sul-
fanylpolystyrene (13). The desired sulfinimidoyl chloride res-
in 10 was prepared by acetylation of 13 to 4-acetylsulfanyl-
polystyrene (14), followed by a treatment with N,N-dichloro-
tert-butylamine in refluxing benzene. The loadings of each
functional groups on polystyrene were determined either by
elemental analysis or by the chemical transformations de-
scribed in the preparation of 3.
Stoichiometric Oxidation of Alcohols Using Poylmer-
Supported Sulfinimidoyl Chloride 10. Similar to resin 3,
the new polymer-supported reagent 10 oxidized various pri-
mary and secondary alcohols to the corresponding carbonyl
compounds in good to high yields in the coexistence of i-
Pr2NEt (Table 2). It was noted that the polymer 10 oxidized
diphenylmethanol and 1,3-diphenylpropan-1-ol more effec-
tively than 3 (Entry 4 and 5).
Moreover, oxidation of benzyl alcohol and 4-phenylcyclo-
hexanol was repeatedly carried out for three times by recycling
10 from a used polymer 11 (Table 3). Since two molar
amounts of 10 were employed in this oxidation, the reaction
was quenched by adding excess amounts of ethanol and two
molar amounts of i-Pr2NEt in order to convert the remaining
equimolar amount of 10 to sulfenamide 11 completely. The
isolated sulfenamide 11 was chlorinated with two molar
amouts of NCS to regenerate sulfinimidoyl chloride 10.
Catalytic Oxidation of Alcohols Using Poylmer-Sup-
ported Sulfinimidoyl Chloride 3 and 10. The sulfenamide
2-catalyzed oxidation of alcohols was developed by in situ
chlorination (oxidation) of 2 with a stoichiometric amount of
NCS to form a real oxidant, sulfinimidoyl chloride 1.2 Based
on this concept, oxidation of alcohols using a catalytic amount
(0.2 molar amount) of polymer-supported sulfinimidoyl chlo-
enol ether 7 and BF3 Et2O at ꢂ78 ꢁC to afford the correspond-
ꢃ
ing aldol adduct 8 in 86% yield (for two steps). Thus, a con-
venient organic synthesis was rapidly carried out by using the
polymer oxidant 3.
Preparation of Polymer-Supported Sulfinimidoyl Chlo-
ride 10. As described above, the stoichiometric oxidation of
alcohols with the polymer-supported sulfinimidoyl chloride
resin 3 was performed conveniently. However, recyclization
of 3 by chlorination of a used resin with NCS was not success-
ful in spite of many trials. It was then assumed that the sul-
fenamide 9 which formed from 3 via the oxidation process
decomposed during its isolation (Scheme 4, reaction 1).
Therefore, preparation of the polymer-supported sulfinimidoyl
chloride 10 whose sulfinimidoyl chloride group was directly
Scheme 4.

1436 Bull. Chem. Soc. Jpn., 76, No. 7 (2003)
Polymer-Supported Sulfinimidoyl Chlorides
Table 2. Stoichiometric Oxidation of Alcohols by Using
Polymer-Supported Sulfinimidoyl Chloride 10
Table 4. Catalytic Oxidation of Alcohols by Using Poly-
mer-Supported Sulfinimidoyl Chlorides (3 and 10)
Entry
Alcohol
Conditionsa)
Cat. Yield/%b)
94 (91)d)
ꢂ78 C–0 C, 1 h 10 94
1c)
2c)
iPr2NEt
3
Entry
1
Alcohol
Methoda)
A
Yield/%b)
98c)
ꢁ
ꢁ
3
4
iPr2NEt
3 92
2
A
94
ꢁ
ꢂ78 C–rt, 1 h
10 92
iPr2NEt
3
A
97
5
10 94
ꢁ
ꢂ78 C–rt, 2 h
4
5
A
A
89
84
6
7
iPr2NEt
3 92
ꢁ
ꢂ78 C–rt, 1 h
10 93
6
7
B
B
86
86
K2CO3, MS4A
ꢁ
8
10 83 (44)e)
ꢂ78 C–rt, 14 h
K2CO3, MS4A
9
3 85
a) Method A: a mixture of alcohol and i-Pr2NEt was added to
the swelled polymer 10 in CH2Cl2 at ꢂ78 ꢁC, and then the
reaction mixture was stirred at ꢂ78 ꢁC for 30 min. Method B:
alcohol was added to the swelled poꢁlymer 10 in CH2Cl2 at 0
ꢁC then i-Pr2NEt was added at ꢂ78 C. The reaction mixture
was stirred at 0 ꢁC for 30 min. b) Isolated yield unless other-
wise noted. c) Determined by GC-analysis.
ꢁ
0 C–rt, 5 h
K2CO3, MS4A
10
10 82
ꢁ
0 C–rt, 2 h
11
12
K2CO3, MS4A
ꢁ
3
83
0 C–rt, 16 h
10 91
a) i-Pr2NEt (2.0 mol. amt.), K2CO3 (10 mol. amt.), and MS4A
(1 g/mmol) were employed. b) Isolated yield unless otherwise
noted. c) The yield was determined by GC-analysis. d) 0.1
mol. amt. of the catalyst 3 was used and the reaction time was
2 h. e) i-Pr2NEt (2.0 mol. amt.) was used as a base (ꢂ78 ꢁC–
rt, 1 h).
Table 3. Oxidation of Alcohols by Recycling Polymer-
Supported Sulfinimidoyl Chloride 10
of the polymer catalyst 3 was reduced to 0.1 molar amount
(Entry 1).
On the other hand, 3 or 10-catalyzed oxidation of simple
primary and secondary alcohols also proceeded smoothly to
give the corresponding carbonyl compounds in good yields by
using K2CO3 as a base (Entries 9–12). However, it was found
that catalytic oxidation with polymer-supported sulfinimidoyl
chlorides generally required a longer reaction time in compar-
ison to the case with monomeric sulfenamide 2.
Yield/%a)
Alcohol
Recycle:
1st
97
2nd
3rd
98
quant.
95
98
87
Conclusion
a) Yield of the corresponding carbonyl compound.
Various primary and secondary alcohols were oxidized to
the corresponding aldehydes and ketones in good-to-high
yields by using a stoichiometric amount of polymer-supported
sulfinimidoyl chlorides, 3 and 10, while a catalytic amount of
these polymer oxidants worked as a catalyst for the oxidation
of alcohols with NCS. Concerning the effect of bases, i-
Pr2NEt was found effective in the 3 or 10-mediated stoichio-
metric oxidation of various alcohols and the catalytic oxidation
ride 3 or 10 was tried by employing NCS as a stoichiometric
oxidant (Table 4). In the 3 or 10-catalyzed oxidation of
benzylic alcohols, i-Pr2NEt was found to be a suitable base
and the carbonyl compounds were obtained in high yields (En-
tries 1–7). The catalytic oxidation of benzyl alcohol to benz-
aldehyde proceeded smoothly in 91% yield when the amount

J. Matsuo et al.
Bull. Chem. Soc. Jpn., 76, No. 7 (2003) 1437
mmol/g, 22.5 g, 20.3 mmol) and DMF (120 mL) were then added
to the above-mentioned mixture at room temperature, and the
reaction mixture was stirred at 60 C for 18 h. After the reaction
of benzylic alcohols with NCS. In the catalytic oxidation of
normal primary and secondary alcohols, on the other hand,
K2CO3 was effective.
ꢁ
was quenched with H2O, the mixture was stirred for 30 min and
filtered. The resin was washed with DMF/H2O (1:1) (100 mL ꢄ
5), CH2Cl2 (100 mL ꢄ 5), and Et2O (100 mL ꢄ 3), and dried at 70
The applicability of the polymer oxidant 10 in organic
synthesis is wider compared to 3 for the following reasons:
i) polymer 10 was prepared by the four-step procedure directly
from polystyrene, ii) it oxidized a variety of alcohols more
effectively than 3, iii) it was employed repeatedly by recycling
the used polymer 11 by chlorination with NCS.
The polymer-supported sulfinimidoyl chlorides, 3 and 10,
are applicable to other oxidation reactions which were carried
out by using monomeric sulfinimidoyl chloride 1. For exam-
ple, 1 was used as an effective oxidant in oxidation (dehydro-
genation) reactions such as oxidation of amines to imines,12
hydroxylamines to nitrones,13 and dehydrogenation of saturat-
ed carbonyl compounds to ꢀ,ꢁ-unsaturated carbonyl com-
pounds.14
ꢁC for 2 h to give 4 (27.3 g) as pale brown beads: IR (KBr, cmꢂ1
)
1227, 687.
4-Sulfanylphenoxymethylpolystyrene (5). To a stirred sus-
pension of 4 (27.3 g) in CH2Cl2 (200 mL) were added TFA (180
mL) and Et3SiH (20 mL) at room temperature, and the mixture
was stirred for 1 h. After the above mixture was filtered, the resin
was washed with CH2Cl2 (100 mL ꢄ 5) and Et2O (100 mL ꢄ 3),
and dried at 70 ꢁC for 2 h to give 5 (23.2 g) as pale yellow beads:
IR (KBr, cmꢂ1) 2561, 1200, 687.
The filtrate was concentrated, and saturated NaHCO3 solution
was added to the residue. This mixture was then extracted with
CH2Cl2 and the combined organic extracts were dried over anhy-
drous Na2SO4, filtered, and concentrated in vacuo. The residue
was purified by column chromatography (silica gel, hexanes) to
give triphenylmethane (3.32 g, 13.6 mmol, 67% for 2 steps).
4-(Acetylsulfanyl)phenoxymethylpolystyrene (6). To a stir-
red suspension of 5 (23.2 g, 20.3 mmol) and pyridine (8.01 g, 101
mmol) in CH2Cl2 (230 mL) was added acetyl chloride (7.95 g,
Experimental
General. Infrared (IR) spectra were recorded on a Horiba
FT300 FT-IR spectrometer. 1H NMR spectra were recorded on
a JEOL EX270 (270 MHz) or JEOL JMN-LA300 (300 MHz)
spectrometer; chemical shifts (ꢂ) are reported in parts per million
relative to tetramethylsilane. Splitting patterns are designated as
s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; br, broad.
13C NMR spectra were recorded on a JEOL EX270 (68 MHz)
spectrometer with complete proton decoupling. Chemical shifts
are reported in parts per million relative to tetramethylsilane with
the solvent resonance as the internal standard (CDCl3; ꢂ 77.0
ppm). High resolution mass spectra (HRMS) were recorded on
a HITACHI M-80B or a JEOL JMS-AX505HA mass spectro-
meter. Elemental analyses were conducted by Elemental Ana-
lyzer 2400CHN (Perkin Elmer) and Ion Chromatograph DX-500
(Dionex) at the Lead Generation Laboratory of Taisho Pharma-
ceutical Co., Ltd. Analytical gas-liquid chromatography (GLC)
was performed on a Shimadzu GC-9A or GC-17A instrument
equipped with a flame ionizing detector and a capillary column
of OV-101 (0.25 mm ꢄ 50 m) or CBP10 (0.25 mm ꢄ 25 m) using
helium as carrier gas. Analytical TLC was performed on Merk
precoated TLC plates (silica gel 60 GF254, 0.25 mm). Silica-gel
column chromatography was carried out on Merk silica gel 60
ꢁ
101 mmol) at 0 C, and the mixture was stirred at room tempera-
ture for 11 h. After the mixture was filtered, the resin was washed
with CH2Cl2 (100 mL ꢄ 3) and Et2O (100 mL ꢄ 2), and dried at
ꢁ
70 C for 2 h to give 6 (23.0 g) as pale orange beads: IR (KBr,
cmꢂ1) 1759, 1705, 1195, 687.
The loading of acetylsulfanyl group was determined as follows:
a mixture of thus-obtained 6 (1.00 g), benzylamine (193 mg, 1.80
mmol) in 1,2-dichloroethane (10 mL) was stirred at 90 ꢁC for 6 h.
The mixture was filtered, and the filtrate was washed with 1 M (1
M = 1 mol dmꢂ3) hydrochloric acid, H2O, saturated NaHCO3,
and brine, dried over anhydrous Na2SO4, filtered, and concentrat-
ed in vacuo. The crude product was purified by thin-layer chro-
matography to give N-benzylacetamide (63.6 mg, 0.43 mmol) as a
colorless solid. Thus, the loading of acetylsulfanyl group of resin
6 was determined to be 0.43 mmol/g.
4-(N-tert-Butylchlorosulfinimidoyl)phenoxymethylpolysty-
rene (3). To a stirred suspension of 6 (5.0 g) in benzene (40 mL)
was added a solution of N,N-dichloro-tert-butylamine (1.42 g, 10
mmol) at room temperature, and the mixture was refluxed for 1.5
h. After the mixture was filtered under an argon atmosphere, the
obtained resin was dried in vacuo at 60 ꢁC for 1 h to give 3 as
bright-yellow beads: IR (KBr, cmꢂ1) 1203, 1108, 687.
The loading of N-tert-butylchlorosulfinimidoyl group was de-
termined as follows: to a stirred suspension of resin 3 (1.0 g) in
CH2Cl2 (10 mL) was added a solution of 4-methoxybenzyl alco-
hol (78.3 mg, 0.5 mmol) in CH2Cl2 (2.0 mL) at room temperature.
The mixture was stirred at room temperature for 2 h. The forma-
tion of 4-methoxybenzyl chloride (0.18 mmol) was detected by
GC-analysis using naphthalene as an internal standard. Thus, the
loading of N-tert-butylchlorosulfinimidoyl group of the resin 3
was determined to be 0.18 mmol/g.
(0.063–0.200 mm).
Preparative thin-layer chromatography
(PTLC) was carried out on silica gel Wakogel B-5F. Powdered
molecular sieves 4A (purchased from nakalai tesque) were dried
in vacuo at 250 ꢁC for 8 h before use. Dry solvents were prepared
by distillation under appropriate drying agents. Chloromethyl-
polystyrene resin (cross-linked with 1% DVB, 200–400 mesh,
0.8–1.0 mmol Cl/g) and polystyrene resin (cross-linked with 1%
DVB, 200–400 mesh) were purchased from Tokyo Kasei Kogyo.
Unless otherwise noted, commercially available reagents were
used without purification. All of the reactions were carried out
under an atmosphere of argon in oven-dried glassware with mag-
netic stirring. The oxidation products were identified by compar-
ing those authentic samples with their GC retention times, spec-
troscopic data such as 1H NMR, 13C NMR, and on analytical
TLC.
Typical Experimental Procedure for the Stoichiometric
Oxidation of Benzylic Alcohol with 3 (Table 1, Entry 1, Meth-
od A). To a slurry of 3 (0.18 mmol/g, 1.0 g, 0.18 mmol) in
CH2Cl2 (10 mL) was added a mixture of 4-nitrobenzyl alcohol
(15.3 mg, 0.10 mmol) and i-Pr2NEt (25.8 mg, 0.20 mmol) in
4-(Tritylsulfanyl)phenoxymethylpolystyrene (4). To a stir-
red suspension of NaH (55%, 2.65 g, 60.8 mmol) in DMF (40 mL)
was added a solution of 4-(tritylsulfanyl)phenol (22.4 g, 60.8
mmol) in DMF (ꢁ60 mL) at room temperature, and the mixture
was stirred at 60 C for 1 h. Chloromethylpolystyrene resin (0.9
ꢁ
CH2Cl2 (2 mL) at ꢂ78 C. The reaction mixture was stirred at
ꢂ78 ꢁC for 30 min, and the reaction was quenched by adding H2O

1438 Bull. Chem. Soc. Jpn., 76, No. 7 (2003)
Polymer-Supported Sulfinimidoyl Chlorides
(2 mL). The mixture was filtered through a Celite pad, and filtrate
was extracted with CH2Cl2. The combined organic extracts were
washed with H2O and brine, dried over anhydrous Na2SO4, fil-
tered and concentrated. The crude product was purified by pre-
parative TLC to afford 4-nitrobenzaldehyde (14.8 mg, 98%).
Typical Experimental Procedure for the Stoichiometric
Oxidation of Non-benzylic Alcohol with 3 (Table 1, Entry
11, Method B). To a stirred slurry of 3 (0.8 g, 0.15 mmol) in
CH2Cl2 (8 mL) was added a solution of cyclohexanol (10.0 mg,
0.10 mmol) in CH2Cl2 (1 mL) at 0 ꢁC. After the mixture was
stirred for 5 min at 0 ꢁC, i-Pr2NEt (25.8 mg, 0.20 mmol) in
CH2Cl2 (1 mL) was added at ꢂ78 ꢁC. The reaction mixture
was stirred at room temperature for 30 min, and the reaction
was quenched by adding 1% HCl solution (5 mL). The mixture
was extracted with CH2Cl2 (20 mL ꢄ 3), and the yield of cyclo-
hexanone (0.092 mg, 92%) was determined by GC-analysis of the
organic extracts using naphthalene as an internal standard.
Oxidation of 4-Nitrobenzyl Alcohol with 3 and Aldol Reac-
tion with 7 (Scheme 3). After 4-nitrobenzyl alcohol (15.3 mg,
0.10 mmol) was oxidized according to the above procedure, the
reaction mixture was filtered through a silica gel pad instead of
quenching the reaction with H2O. Evaporation of the solvent gave
a crude 4-nitrobenzaldehyde (13.8 mg). A solution of trimethyl-
silyl enol ether 7 (38.5 mg, 0.20 mmol) in CH2Cl2 (1.5 mL) was
added to a solution of thus-obtained 4-nitrobenzaldehyde in
2576, 687. Anal. Found: C, 83.83; H, 7.34; S, 7.37% (2.30 mmol/
g).
4-Acetylsulfanylpolystyrene (14). To the stirred suspension
of 13 (2.30 mmol/g, 15.8 g, 36.3 mmol) and pyridine (9.3 mL, 182
mmol) in CH2Cl2 (220 mL) was added acetyl chloride (8.2 mL,
ꢁ
182 mmol) at 0 C, and the reaction mixture was stirred at room
temperature for 12 h. The mixture was filtered, and the resin was
washed with CH2Cl2 and Et2O, and dried in vacuo at 60 ꢁC for 2 h
to give 14 (16.0 g); IR (KBr, cmꢂ1) 1751, 1705, 694. Anal.
Found: C, 82.41; H, 7.11; S, 6.50% (2.03 mmol/g).
The loading of acetylsulfanyl group was determined by another
method as follows: the mixture of 14 (296 mg), benzylamine (285
mg, 2.66 mmol), and THF (3 mL) was refluxed for 1 h. N-Ben-
zylacetamide (0.60 mmol) was detected by GC-analysis of the
reaction mixture using biphenyl as an internal standard. Thus,
the loading was determined to be 2.02 mmol/g.
4-(N-tert-Butylchlorosulfinimidoyl)polystyrene (10). To a
stirred suspension of 14 (2.02 mmol/g, 2.00 g) in dry benzene
(20 mL) was added a solution of N,N-dichloro-tert-butylamine
(1.73 g, 12.2 mmol) in dry benzene (3.0 mL) at room temperature,
and the reaction mixture was refluxed for 1.5 h. After evaporation
of the solvent in vacuo, the residue was suspended in CH2Cl2 (30
mL) for 30 min, and this suspension was filtered by a glass filter
under an argon atmosphere. The resin was washed in this manner
with CH2Cl2 (15 mL ꢄ 3), and then the resin was dried in vacuo at
room temperature for 2 h to give a bright yellow resin 10: IR
(KBr, cmꢂ1) 1211, 1141, 694. Anal. Found: C, 71.63; H, 7.39;
N, 2.53; S, 4.90 (1.53 mmol/g); Cl, 9.08%.
The loading of N-tert-butylchlorosulfinimidoyl group was de-
termined by another method as follows: to a stirred suspension of
10 (300 mg) in CH2Cl2 (3 mL) was added a solution of 4-meth-
oxybenzyl alcohol (117 mg, 0.85 mmol) in CH2Cl2 (2 mL) at
room temperature, and the mixture was stirred for 20 h. 4-Meth-
oxybenzyl chloride (0.46 mmol) was detected by GC-analysis of
the reaction mixture using naphthalene as an internal standard.
Then, the loading of N-tert-butylchlorosulfinimidoyl group was
determined to be 1.53 mmol/g.
Typical Experimental Procedure for the Oxidation of Alco-
hols by Recycling 10 (Table 3). To a stirred suspension of 10
(0.72 mmol/g, 0.54 g, 0.39 mmol) in CH2Cl2 (3.0 mL) was added
a solution of benzyl alcohol (21 mg, 0.19 mmol) and i-Pr2NEt (50
mg, 0.39 mmol) at ꢂ78 ꢁC. After the mixture was stirred at ꢂ78
ꢁC for 30 min, the reaction was quenched by adding a solution of
i-Pr2NEt (50 mg, 0.39 mmol) in ethanol (2 mL). The mixture was
filtered and the resin was washed with CH2Cl2 (15 mL ꢄ 3). The
yield of benzaldehyde (0.18 mmol, 95%) was determined by GC-
analysis of the filtrate using naphthalene as an internal standard.
After the resin was further washed with Et2O (10 mL ꢄ 3), it was
dried in vacuo at room temperature for 2 h. Thus-obtained resin
11 was suspended in CH2Cl2 (2.5 mL), and a solution of NCS (60
mg, 0.45 mmol) in CH2Cl2 (2.5 mL) was added at room
temperature. After the mixture was stirred for 1 h at room tem-
perature, a solution of benzyl alcohol (16 mg, 0.15 mmol) and i-
Pr2NEt (40 mg, 0.31 mmol) in CH2Cl2 (2.0 mL) was added at
ꢂ78 ꢁC. After the mixture was stirred at the same temperature for
30 min, the reaction was quenched by adding a solution of i-
Pr2NEt (40 mg, 0.31 mmol) in ethanol (2.0 mL), and the mixture
was stirred up to room temperature. The mixture was filtered by
glass-filter, and the yield of benzaldehyde (0.15 mmol, quant.) was
determined by GC-analysis.
CH2Cl2 (2 mL). Then, a solution of BF3 Et2O (28.4 mg, 0.20
ꢃ
mmol) in CH2Cl2 (1.5 mL) was added to the above-mentioned
mixture at ꢂ78 ꢁC. After the mixture was stirred for 30 min at the
same temperature, the reaction was quenched with saturated aque-
ous NaHCO3, and the mixture was extracted with CH2Cl2. After
the combined organic extracts were evaporated, THF (10 mL) and
1 M hydrochloric acid (10 mL) were added to the residue, and the
mixture was stirred at room temperature for 3 h. After THF was
evaporated, the mixture was extracted with Et2O, and combined
organic extracts were washed with H2O and brine, dried over
anhydrous Na2SO4, filtered, and concentrated. The crude product
was purified by preparative TLC (silica gel, hexane/ethyl acetate
= 2/1) to give aldol adduct 3-hydroxy-3-(4-nitrophenyl)-1-phen-
ylpropan-1-one (8) (23.2 mg, 86%) as a colorless oil: 1H NMR
(270 MHz, CDCl3) ꢂ 3.29–3.46 (2H, m), 3.89 (1H, brs), 5.44–5.48
(1H, m), 7.46–7.53 (2H, m), 7.59–7.64 (3H, m), 7.91–7.96 (2H,
m), 8.22–8.26 (2H, m); 13C NMR (68 Hz, CDCl3) ꢂ 46.9, 69.2,
123.8, 126.5, 128.1, 128.8, 134.0, 136.1, 147.3, 150.2, 199.5.
4-Sulfanylpolystyrene (13). To a stirred solution of polysty-
rene resin (14.9 g), N,N,N0,N0-tetramethylethylenediamine (21.6
mL, 143 mmol) in cyclohexane (120 mL) was added dropwise
butyllithium (1.57 M in hexane, 110 mL, 172 mmol) atꢁ room
temperature. After the reaction mixture was stirred at 65 C for
2 h, solvents were removed. THF (220 mL) was added to the
residue, and sulfur (4.60 g, 143 mmol) was then added to the
suspension at 0 ꢁC. After the reaction mixture was stirred at room
temperature for 15 h, the reaction was quenched with 3 M hydro-
chloric acid (150 mL). The mixture was filtered, and the resin was
washed with H2O, THF, CH2Cl2, and Et2O, and dried in vacuo at
60 ꢁC for 2 h to give 12 (17.7 g). To the stirred suspension of the
obtained resin 12 (17.7 g) in THF (250 mL) was added LiAlH4
ꢁ
(2.02 g, 53.1 mmol) at 0 C, and the reaction mixture was stirred
at room temperature for 3 h. The reaction was quenched by
adding H2O (2 mL), followed by the addition of 15% aqueous
NaOH solution (2 mL) and H2O (6 mL). The mixture was filtered,
and the resin was washed with H2O, THF, CH2Cl2, and Et2O, and
Typical Experimental Procedure for the Catalytic Oxida-
tion of Benzylic Alcohols by Using 10, NCS, and i-Pr2NEt
dried in vacuo at 60 ꢁC for 2 h to give 13 (15.8 g): IR (KBr, cmꢂ1
)

J. Matsuo et al.
Bull. Chem. Soc. Jpn., 76, No. 7 (2003) 1439
(Table 4, Entry 4). To a stirred suspension of 10 (1.25 mmol/g,
0.13 g) in CH2Cl2 (3.0 mL) was added a solution of 4-nitrobenzyl
alcohol (124 mg, 0.81 mmol) and i-Pr2NEt (209 mg, 1.62 mmol)
in CH2Cl2 (2.0 mL) at ꢂ78 ꢁC. Then, NCS (216 mg, 1.62 mmol)
was added and the mixture was stirred at room temperature for 1
h. After the reaction was quenched with H2O (1 mL), the mixture
was filtered through a Celite pad, and the filtrate was extracted
t, J ¼ 6:60 Hz), 3.61 (2H, t, J ¼ 6:60 Hz), 7.12–7.32 (9H, m),
7.42–7.46 (6H, m); 13C NMR (68 Hz, CDCl3) ꢂ 25.6, 26.2, 29.2,
29.9, 32.7, 63.0, 63.5, 86.2, 126.8, 127.7, 128.7, 144.5. HRMS
(ESI) Found: m=z 375.2324. Calcd for C26H31O2 [M + H]:
375.2317.
3-Trityloxypropanal.20 Rf 0.70 (hexane/ethyl acetate = 3/1);
IR (KBr, cmꢂ1) 1728, 1597, 1489, 1450; 1H NMR (270 MHz,
CDCl3) ꢂ 1.23–1.42 (4H, m), 1.56–1.66 (4H, m), 2.38 (2H, dt,
J ¼ 1:90, 7.20 Hz), 3.05 (2H, t, J ¼ 6:60 Hz), 7.18–7.32 (9H, m),
7.41–7.45 (6H, m), 7.93 (1H, t, J ¼ 1:90 Hz); 13C NMR (68 Hz,
CDCl3) ꢂ 22.0, 26.0, 29.0, 29.8, 43.8, 63.4, 86.3, 126.8, 127.7,
128.7, 144.4, 202.8. HRMS (ESI) Found: m=z 373.2168. Calcd
for C26H29O2 [M + H]: 373.2152.
with CH2Cl2.
The combined organic extracts were
washed with H2O and brine, dried over anhydrous Na2SO4,
filtered, and concentrated in vacuo. The crude product was pu-
rified by preparative thin-layer chromatography (hexane/ethyl
acetate = 3/1) to afford 4-nitrobenzaldehyde (112 mg, 92%).
Typical Experimental Procedure for the Catalytic Oxida-
tion of Non-Benzylic Alcohols by Using 10, NCS, K2CO3, and
MS4A (Table 4, Entry 12). To a stirred suspension of K2CO3
(950 mg, 6.87 mmol), MS4A (687 mg), NCS (184 mg, 1.38
mmol), and 10 (1.25 mmol/g, 0.11 g) in CH2Cl2 (5.0 mL) was
added a solution of 4-phenylcyclohexan-1-ol (121 mg, 0.69 mmol)
in CH2Cl2 (2.0 mL) at 0 ꢁC. After the mixture was stirred at room
temperature for 16 h, it was filtered through a Celite pad, and the
filtrate was extracted with CH2Cl2. The combined organic ex-
tracts were washed with H2O and brine, dried over anhydrous
Na2SO4, filtered, and concentrated in vacuo. The crude product
was purified by preparative thin-layer chromatography (hexane/
ethyl acetate = 4/1) to afford 4-phenylcyclohexan-1-one (108 mg,
91%).
7-tert-Butyldiphenylsiloxyheptan-1-ol.21
Rf 0.20 (hexane/
ethyl acetate = 4/1); 1H NMR (270 MHz, CDCl3) ꢂ 1.04 (9H,
s), 1.31 (6H, m), 1.54 (4H, m), 1.78 (1H, brs), 3.63 (2H, t, J ¼
6:60 Hz), 3.70 (2H, t, J ¼ 6:60 Hz), 7.34-7.41 (6H, m), 7.64–7.67
(4H, m); 13C NMR (68 Hz, CDCl3) ꢂ 19.3, 25.7, 25.8, 26.9, 29.2,
32.5, 32.8, 63.0, 63.9, 127.4, 129.4, 134.0, 135.4.
7-tert-Butyldiphenylsiloxyheptanal.21 Rf 0.60 (hexane/ethyl
acetate = 4/1); 1H NMR (270 MHz, CDCl3) ꢂ 1.05 (9H, s), 1.28–
1.41 (4H, m), 1.51–1.66 (4H, m), 2.39 (2H, dt, J ¼ 1:90, 7.50 Hz),
3.65(2H, t, J ¼ 6:60 Hz), 7.34–7.42 (6H, m), 7.64–7.68 (4H, m),
9.74 (1H, t, J ¼ 1:90 Hz); 13C NMR (68 Hz, CDCl3) ꢂ 19.3, 22.1,
25.6, 26.9, 28.9, 32.3, 43.9, 63.7, 127.5, 129.4, 133.9, 135.4,
202.6.
1,3-Diphenylpropan-1-ol.15 Rf 0.40 (hexane/ethyl acetate =
4/1); 1H NMR (300 MHz, CDCl3) ꢂ 1.94–2.17 (3H, m), 2.59–2.78
(2H, m), 4.65–4.73 (1H, m), 7.16–7.36 (10H, m); 13C NMR (75.5
Hz, CDCl3) ꢂ 32.0, 40.4, 73.8, 125.8, 125.9, 127.6, 128.3, 128.4,
128.5, 141.7, 144.5.
We are grateful to Professor Teruaki Mukaiyama for valu-
able discussions and his kind help in preparing this manuscript.
This study was supported in part by the Grant-in-Aid of the
21st Century COE Program from the Ministry of Education,
Culture, Sports, Science and Technology (MEXT). The au-
thors thank Miss Harumi Akiyama and Miss Hisayo Sekine,
Taisho Pharmaceutical Co., Ltd., for the elemental analysis
and Dr. Hirokazu Ohsawa, Banyu Pharmaceutical Company,
for mass spectrometry analysis.
1,3-Diphenylpropan-1-one.16 Rf 0.60 (hexane/ethyl acetate
= 4/1); 1H NMR (270 MHz, CDCl3) ꢂ 3.07 (2H, t, J ¼ 7:50 Hz),
3.31 (2H, t, J ¼ 7:50 Hz), 7.15–7.33 (5H, m), 7.40–7.56 (3H, m),
7.93–8.00 (2H, m); 13C NMR (68 Hz, CDCl3) ꢂ 30.2, 40.5, 126.0,
127.9, 128.3, 128.4, 128.5, 132.9, 136.7, 141.1, 199.0.
(2E)-5-Phenylpent-2-en-1-ol.17 Rf 0.20 (hexane/ethyl acetate
1
= 5/1); H NMR (300 MHz, CDCl3) ꢂ 2.33–2.41 (2H, m), 2.68–
2.73 (2H, m), 4.06 (2H, d, J ¼ 4:80 Hz), 5.61–5.78 (2H, m), 7.16–
7.30 (5H, m); 13C NMR (75.5 Hz, CDCl3) ꢂ 33.9, 35.5, 63.6,
125.8, 128.3, 128.4, 129.5, 132.2, 141.6.
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4
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1440 Bull. Chem. Soc. Jpn., 76, No. 7 (2003)
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¨
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8
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ꢀ
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9
The resin 3 should be handled under strictly anhydrous
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6
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