RSS-Feed abonnieren
DOI: 10.1055/s-2005-868492
Iridium-Catalyzed Oxidative Dimerization of Primary Alcohols to Esters Using 2-Butanone as an Oxidant
Publikationsverlauf
Publikationsdatum:
25. April 2005 (online)
![](https://www.thieme-connect.de/media/synlett/200509/lookinside/thumbnails/10.1055-s-2005-868492-1.jpg)
Abstract
Oxidative dimerization of primary alcohols with 2-butanone in the presence of an amino alcohol-based Ir bifunctional catalyst was accomplished for the first time. The reaction proceeds with 1-2 mol% of the catalyst and 0.3 mol equivalents of K2CO3 in 2-butanone at room temperature to give the corresponding dimeric esters in 30-93% yield.
Key words
alcohols - esters - hydrogen transfer - iridium catalyst - oxidative dimerization
-
1a
Mulzer J. In Comprehensive Organic Functional Group Transformations Vol. 5:Katritzky AR.Meth-Cohn O.Rees CW.Moody CJ. Elsevier Science Ltd.; Oxford: 1995. p.121 -
1b
Larock RC. Comprehensive Organic Transformations VCH Publishers, Inc.; New York: 1989. p.835 -
1c
Hudlicky M. Oxidations in Organic Chemistry ACS Monograph Series, American Chemical Society; Washington DC: 1990. p.131 - For recent examples of Tishchenko and related reactions, see:
-
2a
Ooi T.Ohmatsu K.Sasaki K.Miura T.Maruoka K. Tetrahedron Lett. 2003, 44: 3191 -
2b
Gnanadesikan V.Horiuchi Y.Ohshima T.Shibasaki M. J. Am. Chem. Soc. 2004, 126: 7782 -
2c For a recent review:
Törmäkangas OP.Koskinen AMP. Recent Res. Dev. Org. Chem. 2001, 5: 225 - 3
Robertson GR. Org. Synth., Coll. Vol. I Wiley and Sons; New York: 1941. p.138 - 4
Al Neirabeyeh M.Ziegler JC.Gross B.Caubère P. Synthesis 1976, 811 - 5
Nwaukwa SO.Keehn PM. Tetrahedron Lett. 1982, 23: 35 - 6
Kageyama T.Kawahara S.Kitamura K.Ueno Y.Okawara M. Chem. Lett. 1983, 1097 - 7
Takase K.Masuda H.Kai O.Nishiyama Y.Sakaguchi S.Ishii Y. Chem. Lett. 1995, 871 - 8
Bhar S.Chaudhuri SK. Tetrahedron 2003, 59: 3493 - 9
Merbouh N.Bobbitt JM.Brückner C. J. Org. Chem. 2004, 69: 5116 - 10
Tohma H.Maegawa T.Kita Y. Synlett 2003, 723 - 11
Nagashima H.Tsuji J. Chem. Lett. 1981, 1171 - 12
Blum Y.Reshef D.Shvo Y. Tetrahedron Lett. 1981, 22: 1541 -
13a
Murahashi S.-I.Ito K.Naota T.Maeda Y. Tetrahedron Lett. 1981, 22: 5327 -
13b
Murahashi S.-I.Naota T.Ito K.Maeda Y.Taki H. J. Org. Chem. 1987, 52: 4319 - 14
Tamaru Y.Yamada Y.Inoue K.Yamamoto Y.Yoshida Z. J. Org. Chem. 1983, 48: 1286 - 15
Masuyama Y.Takahashi M.Kurusu Y. Tetrahedron Lett. 1984, 25: 4417 - 16
Wang L.Eguchi K.Arai H.Seiyama T. Chem. Lett. 1986, 1173 -
17a
Suzuki T.Morita K.Tsuchida M.Hiroi K. Org. Lett. 2002, 4: 2361 -
17b
Suzuki T.Morita K.Matsuo Y.Hiroi K. Tetrahedron Lett. 2003, 44: 2003 -
17c
Suzuki T.Morita K.Tsuchida M.Hiroi K. J. Org. Chem. 2003, 68: 1601 - Recent examples of hydrogen transfer reaction using Cp*Ir complexes, see:
-
18a
Mashima K.Abe T.Tani K. Chem. Lett. 1998, 1199 -
18b
Murata K.Ikariya T.Noyori R. J. Org. Chem. 1999, 64: 2186 -
18c
Ogo S.Makihara N.Watanabe Y. Organometallics 1999, 18: 5470 -
18d
Ogo S.Makihara N.Kaneko Y.Watanabe Y. Organometallics 2001, 20: 4903 -
18e
Fujita K.Furukawa S.Yamaguchi R. J. Organomet. Chem. 2002, 649: 289 -
18f
Fujita K.Yamamoto K.Yamaguchi R. Org. Lett. 2002, 4: 2691 -
18g
Abura T.Ogo S.Watanabe Y.Fukuzumi S. J. Am. Chem. Soc. 2003, 125: 4149 -
18h
Fujita K.Li Z.Ozeki N.Yamaguchi R. Tetrahedron Lett. 2003, 44: 2687 -
18i
Fujita K.Kitatsuji C.Furukawa S.Yamaguchi R. Tetrahedron Lett. 2004, 45: 3215 -
18j
Fujita K.Fujii T.Yamaguchi R. Org. Lett. 2004, 6: 3525 -
18k
Hanasaka F.Fujita K.Yamaguchi R. Organometallics 2004, 23: 1490 - 20 The use of other bases, such as Na2CO3, Cs2CO3, KHCO3, and KOAc resulted in lower reactivity. Although the role of the K2CO3 is not clear at present, it might increase the nucleophilicity of 1 to the corresponding aldehyde for the formation of hemiacetal. For the mechanistic study of acid- and base-catalyzed formation of the hemiacetal, see:
Sorensen PE.Jencks WP. J. Am. Chem. Soc. 1987, 109: 4675
References
Related oxidative lactonization of diols in the presence of acetone was reported by Murahashi et al., see ref. 13a.
21
General Procedure for the Oxidative Dimerization of 1.
A 10 mL test tube equipped with a magnetic stirring bar was charged with 42 mg (0.3 mmol) of K2CO3 and 1.0 mmol of alcohol under Ar. Then a solution of 11 mg (0.02 mmol, 2 mol%) of Ir complex 3 in butanone (0.24 mL, 2.7 mmol) was added to the above mixture and stirred at r.t. The mixture was passed through a short silica gel column (12 g, EtOAc) to remove the catalyst. The yields for the products of 2c and 2d were determined by gas chromatography using authentic samples and appropriate correction factors. The products of 2a, 2b, and 2d-m were purified by silica gel column chromatography (hexane-EtOAc).
Although TONs were not optimized at the moment, they were roughly calculated to be in range between 17 and 23 for most substrates [with single entry as high as 40 (entry 7)].
23The mechanism of saturation is not clear at present. Partially saturated products were observed even without K2CO3 under a high-concentration condition (4.2 M). However, such saturated products were not observed with K2CO3 under a diluted condition (0.08 M). See also ref. 17c.