ORGANIC
LETTERS
1
999
Vol. 1, No. 5
13-715
Oxidative Cleavage of vic-Diols to
Aldehydes with Dioxygen Catalyzed by
Ru(PPh ) Cl on Active Carbon
7
3
3 2
Eiichiro Takezawa, Satoshi Sakaguchi, and Yasutaka Ishii*
Department of Applied Chemistry, Faculty of Engineering & High Technology
Research Center, Kansai UniVersity, Suita, Osaka 564-8680, Japan
Received June 2, 1999
ABSTRACT
A variety of vic-diols were first successfully cleaved to the corresponding aldehydes with dioxygen catalyzed by Ru(PPh
carbon in fair to good yields. For example, treatment of 1,2-octandiol and 1,2-cyclooctanediol with dioxygen in the presence of Ru(PPh
in PhCF at 60 °C for 15 h produced heptanal and 1,8-octanedial in 77% and 76% yields, respectively.
3
)
3
Cl
2
on active
3
)
3
2
Cl /C
3
Oxidative cleavage of Vic-diols is an important and frequently
In an initial screening, we tested the oxidation of 1,2-
octanediol (1) under dioxygen atmosphere (1 atm) by using
several ruthenium complexes which catalyze the aerobic
oxidation of primary alcohols to aldehydes (Table 1).10
used transformation in organic synthesis. Typically, two
1
2
oxidants, lead tetraacetate and periodic acid, are used for
this purpose. On occasion, other reagents such as ceric
3
4
5
11
ammonium nitrate, sodium bismuthate, and CrO
3
cause
Although tetrapropylammonium perruthenate (TPAP)
1
2
the cleavage of vicinal diols. However, these reagents have
the obvious drawbacks of being toxic and producing a large
amount of waste. There has been reported the catalytic
cleavage of Vic-diols to carboxylic acids with several oxidants
and Ru(PPh ) Cl
2
are reported to catalyze the aerobic
3
3
oxidation of primary alcohols to aldehydes, diol 1 was
cleaved by these catalysts to heptanal (2) in low conversion
and selectivity (entries 1 and 2). The formation of acetal 3
by Ru(PPh ) Cl would be based on the acetalization of the
6
7
8
such as t-BuOOH, H
2 2 2
O , and O . To our knowledge,
3
3
2
however, few papers have been published on the catalytic
cleavage of Vic-diols to aldehydes with O , probably because
2
of the difficulty to suppress the formation of overoxidation
products such as carboxylic acids. Our approach is to
establish the oxidative cleavage of Vic-diols to aldehydes with
resulting heptanal 2 with 1 by an acid like hydrochloric acid,
probably generated by the decomposition of a part of the
Ru(PPh ) Cl during the reaction. However, Ru (CO) ,
9
3
3
2
3
12
RuCl , and RuO were inactive in the present transformation
3
2
(entries 3-5).
O
2
via transformation of Vic-diols to aldehydes.
Previously, we have learned that the catalytic activity of
a mixed addenda molybdovanadophosphate (NPMoV) whose
(
1) Wolf, F. J.; Weijjlard, J. Org. Synth., Collect. Vol. 1963, 4, 124.
average composition is approximately indicated as (NH
PMo 40 in the aerobic oxidation of benzyl alcohols was
considerably enhanced by supporting on the active carbon.
4 5 6
) H -
(2) Hudlicky, M. Oxidations in Organic Chemistry; American Chemical
Society: Washington, DC, 1981; p 159.
3) Trahanovsky, W. S.; Young, L. H.; Bierman, M. H. J. Org. Chem.
969, 34, 869.
4) (a) Rigby, W. J. Chem. Soc. 1950, 1907. (b) Uskokovic, M.; Gut,
M.; Trachtenberg, E. N.; Klyne, W.; Dorfman, R. I. J. Am. Chem. Soc.
960, 82, 4965.
4 8
V O
(
13
1
(
(10) General Procedure. To a solution of Ru complex (2 mol %) in
R,R,R-trifluorotoluene (5 mL) in a flask was added diol (1 mmol), and a
balloon filled with O2 (1 atm) was attached to the flask. The mixture was
vigorously stirred at 60 °C for 15 h. After removal of catalyst by filtration,
the solvent was evaporated under reduced pressure. Products were isolated
by flash chromatography on silica gel (n-hexane/AcOEt ) 2:1).
(11) (a) Lenz, R.; Ley, S. T. J. Chem. Soc., Perkin Trans 1 1997, 3291.
(b) Marco, I. E.; Giles, P. R.; Tsukazaki, M.; Regnaut, I. C.; Urch, C. J.;
Brown, S. M. J. Am. Chem. Soc. 1997, 119, 12661.
1
(5) Tavares, D. F.; Borger, J. P. Can. J. Chem. 1966, 44, 1323.
(6) Kanada, K.; Morimoto, K.; Imanaka, T. Chem. Lett. 1988, 1295.
(7) (a) Veturello, C.; Ricci, M. J. Org. Chem. 1986, 51, 1599. (b) Ishii,
Y.; Yamawaki, K.; Ura, T.; Yamada, H.; Yoshida, T.; Ogawa, M. J. Org.
Chem. 1988, 53, 3587. (c) Iwahama, T.; Sakaguchi, S.; Nishiyama, Y.; Ishii,
Y. Tetrahedron Lett. 1995, 36, 6293.
(
8) (a) Vries, G. D.; Schors, A. Tetrahedron Lett. 1968, 9, 5689. (b)
Felthouse, T. R. J. Am. Chem. Soc. 1987, 109, 7566.
9) Okamoto, T.; Sakai, K.; Oka, S. J. Am. Chem. Soc. 1988, 110, 1187.
(12) Hanyuu, A.; Takezawa, E.; Sakaguchi, S.; Ishii, Y. Tetrahedron
Lett. 1998, 39, 5557.
(
1
0.1021/ol990117w CCC: $18.00 © 1999 American Chemical Society
Published on Web 08/05/1999