H. Egami et al. / Tetrahedron Letters 46 (2005) 783–786
785
1
Table 2. Aerobic oxidation of 7 in the presence of various alcohols 11–
a
ture was traced by H NMR analysis to calculate the
ratio of unreacted alcohols, aldehyde, and ketone. In
all the reactions, the mass balances were excellent and
1
3 using complexes 5 or 6 as catalyst
1
9
no formation of carboxylic acid was detected.
In conclusion, we were able to demonstrate that a rea-
sonably modified (ON)Ru(salen) complex bearing an
apical hydroxo ligand oxidized primary aliphatic alco-
hol with good selectivity even in the presence of acti-
vated secondary alcohol without addition of a base
and/or mediator. Selective oxidation of 1,n-diols is very
often encountered in syntheses of complex molecules
and the present oxidation should provide a useful tool
for oxidation of terminal alcohols.
Entry Substrate
R)
Catalyst IRR Yield of Yield of
aldehyde ketone
(
9
(%)
75
45
(%)
b
1
2
3
4
11(PhC„C)
11
11
5
6
6
6
>30
>30
5
1
9
3
b
b,c
b
100
42
12 [(E)-(c-C
CH@CH]
12
6
H
11)-
20
b,d
e
5
6
6
5
93
61
16
21
13 [(E)-
PhCH@CH]
136
12
9
e
7
45
14
References and notes
a
6 6
Reactions were carried out for 24 h in C D at 10 ꢀC under irradia-
tion with a halogen lamp by using 2 mol% of catalyst.
2-Bromonaphthalene was used as the internal standard.
b
c
1. (a) Ley, S. V.;Madin, A. In Comprehensive Organic
Synthesis;Trost, B. M., Fleming, I., Ley, S. V., Eds.;
Pergamon: Oxford, 1991;Vol. 7, pp 251–289;(b) Lee, T.
V. In Comprehensive Organic Synthesis;Trost, B. M.,
Fleming, I., Ley, S. V., Eds.;Pergamon: Oxford, 1991;
Vol. 7, pp 291–303;(c) Procter, G. In Comprehensive
Organic Synthesis;Trost, B. M., Fleming, I., Ley, S. V.,
Eds.;Pergamon: Oxford, 1991;Vol. 7, pp 305–
Reaction was carried out for 48 h with 4 mol% of catalyst.
Reaction was carried out for 36 h with 4 mol% of catalyst.
Pentamethylbenzene was used as the internal standard.
d
e
3
27.
2
. For non-aerobic highly chemoselective oxidation of
primary alcohols, (a) Tomioka, H.;Takai, K.;Oshima,
K.;Nozaki, H. Tetrahedron Lett. 1981, 22, 1605–1608;(b)
Saint-Arnan, E.;Menage, S.;Pierre, J.-L.;Defrancq, E.;
Gellon, G. New J. Chem. 1998, 393;(c) Luca, L. D.;
Giacomelli, G.;Porcheddu, A. Org. Lett. 2001, 3, 3041;(d)
Matsuo, J.;Iida, D.;Yamanaka, H.;Mukaiyama, T.
Tetrahedron 2003, 59, 6739.
Scheme 2.
3
. (a) Sheldon, R. A.;Arends, I. W. C. E. In Advances in
catalytic activation of dioxygen by metal complexes;
Simandi, L. I., Ed.;Kluwer Academic: Dordrecht, 2003,
p 123;(b) Nishimura, T.;Onoue, T.;Ohe, K.;Uemura, S.
J. Org. Chem. 1999, 64, 6750–6755;(c) Marko´, I-E.;Giles,
and the product ratio reflects the relative reaction ratio
between the alcohols, as long as the product is stable un-
der the reaction conditions. Accordingly, we examined
oxidation of 1-phenylbutane-1,4-diol (14) and 6-cyclo-
hexyl-5-hexene-1,4-diol (15) with complex 6 as the cata-
lyst in CDCl3 (Scheme 2) and the ratios of the
products (lactol 16 and hydroxy ketone 17) were found
to be 79:1 and 22:1, as expected from the IRRs of the
corresponding intermolecular reactions (7/8 and 7/12)
P-R.;Tsukazaki, M.;Brown, S-M.;Urch, C-J.
1
3
109.
Science
996, 2044–2046;(d) Stolz, B. M. Chem. Lett. 2004, 33,
62–367;(e) Irie, R.;Katsuki, T. Chem. React. 2004, 4, 96–
1
7
4. (a) Hanyu, A.;Takezawa, E.;Sakaguchi, S.;Ishii, Y.
Tetrahedron Lett. 1998, 39, 5557–5560;(b) Semmelhack,
M. F.;Schmid, C. R.;Cortes, D. A.;Chou, C. S. J. Am.
Chem. Soc. 1984, 106, 3374–3376;(c) Gamez, P.;Arends,
I. W. C. E.;Reedijk, J.;Sheldon, R. A. Chem. Commun.
(
vide supra).
2
003, 2414–2425;(d) Choi, K.-M.;Akita, T.;Mizugaki,
T.;Ebitani, K.;Kaneda, K. New J. Chem. 2003, 27, 324–
28;(e) Hasan, M.;Musawir, M.;Davey, P. N.;
Kozhevnikov, I. V. J. Mol. Catal. A 2002, 180, 77–84;
f) Lorber, C. Y.;Smidt, S. P.;Osborn, J. A. Eur. J. Inorg.
As might be expected, 1-decanol (7) was oxidized with
perfect selectivity in the presence of 2-decanol by using
3
6
as catalyst.
(
Competitive oxidations of primary aliphatic and second-
ary activated alcohols were examined typically as fol-
lows. Primary and secondary alcohols (0.1 mmol each)
were weighed into a Schlenk tube (Pyrex) followed by
addition of pentamethylbenzene or 2-bromonaphthal-
ene (0.1 mmol) as an internal standard and benzene-d6
Chem. 2000, 655–658;(g) Ebitani, K.;Fujie, Y.;Kaneda,
K. Langmuir 1999, 15, 3557–3562;(h) Hinzen, B.;Lenz,
R.;Ley, S. V. Synthesis 1998, 977–979;(i) Kaneda, K.;
Fujie, Y.;Ebitani, K. Tetrahedron Lett. 1997, 38, 9023–
9
1
026;(j) Liu, X.;Qiu, A.;Sawyer, D. T. J. Am. Chem. Soc.
993, 115, 3239–3243;(k) Bilgrien, C.;Davis, S.;Drago,
R. J. Am. Chem. Soc. 1997, 109, 3786–3787;(l) Musawir,
M.;Davey, P. N.;Kelly, G.;Kozhevnikov, I. V. Chem.
(
1 mL). An aliquot was taken out of the tube and sub-
1
mitted to H NMR (400 MHz) analysis to adjust the
molar ratio of the components. To the solution was
added 6 (1.4 mg, 2 lmol), and the mixture was irradi-
ated by using a halogen lamp (150 W) for 24 h at
Commun. 2003, 1414–1415;(m) Matsumoto, M.;Ito, S. J.
Chem. Soc., Chem. Commun. 1981, 907–908;(n) Matsu-
moto, M.;Watanabe, N. J. Org. Chem. 1984, 49, 3436–
3437;(o) Uozumi, Y.;Nakano, R. Angew. Chem., Int. Ed.
2003, 42, 194–197.
1
8
1
0 ꢀC with vigorous stirring in air. The reaction mix-