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Synlett 2004(6): 1120-1121
DOI: 10.1055/s-2004-822909
DOI: 10.1055/s-2004-822909
SPOTLIGHT
© Georg Thieme Verlag Stuttgart · New York
Diazabicyclo[2.2.2]octane - DABCO
Weitere Informationen
Publikationsverlauf
Publikationsdatum:
08. April 2004 (online)
Biographical Sketches
Introduction
Diazabicyclo[2.2.2]octane, DABCO (I), is the most commonly used catalyst in the Baylis-Hillman reaction. [1] This important carbon-carbon bond forming reaction has received much attention in recent years because it provides multifunctional molecules with a newly created stereocenter, which are versatile building blocks in organic synthesis.
The generally accepted mechanism is illustrated in Scheme 1 for the DABCO-catalyzed Baylis-Hillman reaction of benzaldehyde with methyl acrylate.
Abstracts
(1) In 1972, Anthony Baylis and Melville Hillman [2] described the reaction of an aldehyde with a broad spectrum of activated alkenes under the influence of DABCO (I). | |
(2) Drewes et al. [3] reported the DABCO (I)-catalyzed intramolecular Baylis-Hillman reaction of the acrylate ester of salicylaldehyde to afford a crystalline coumarin salt as the major product being in evidence with the proposed mechanism. | |
(3) Chiral C2-symmetric 2,3-disubstituted DABCOs [4] have been effectively utilized for the asymmetric Baylis-Hillman reaction between p-nitrobenzaldehyde and methyl vinyl ketone under high pressure (5-10 kbar) to obtain asymmetric induction up to 47% ee. | |
(4) Leahy et al. [5] described the most impressive asymmetric Baylis-Hillman reaction using Oppolzer’s sultam as chiral auxiliary and DABCO as catalyst to obtain the chiral dioxanone product in high enantiomeric purity (>99% ee). It is noteworthy that the sultam auxiliary was fortuitously cleaved by the addition of a second equivalent of aldehyde. | |
(5) We have recently reported the DABCO-catalyzed diastereoselective Baylis-Hillman reaction using sugar acrylate [6] [7] as chiral Michael acceptor and sugar aldehyde [8] as chiral electrophile to achieve moderate to good diastereoselectivities (5-86% de). | |
(6) Recently, Hu and co-workers [9] have shown that the use of stoichiometric base catalyst I, in an aqueous medium, accelerates the Baylis-Hillman reaction. Moreover, the less reactive Michael acceptor acrylamide, [10] which normally reacts only under high pressure, also undergoes Baylis-Hillman coupling with reactive electrophiles under these conditions. | |
(7) The Baylis-Hillman coupling of salicylaldehyde [11] [12] with various activated alkenes in the presence of I proceeds with regioselective cyclization to afford the corresponding 3-substituted chromene derivatives. |
- For review see:
-
1a
Basavaiah D.Rao PD.Hyma RS. Tetrahedron 1996, 52: 8001 -
1b
Ciganek E. The Morita-Baylis-Hillman Reaction, In Organic Reactions Vol. 51:Paquette LA. John Wiley & Sons; New York: 1997. p.201-350 -
1c
Langer P. Angew. Chem. Int. Ed. 2000, 39: 3049 -
1d
Basavaiah D.Rao AJ.Satyanarayana T. Chem. Rev. 2003, 103: 811 - 2
Baylis AB, andHillman MED. inventors; German Patent 2155113. ; ,34174q - 3
Drewes SE.Njamela OL.Emslie ND.Ramesar N.Field JS. Synth. Commun. 1993, 23: 2807 - 4
Oishi T.Oguri H.Hirama M. Tetrahedron: Asymmetry 1995, 6: 1241 - 5
Brzezinski LJ.Rafel S.Leahy JW. J. Am. Chem. Soc. 1997, 119: 4317 - 6
Radha Krishna P.Kannan V.Ilangovan A.Sharma GVM. Tetrahedron: Asymmetry 2001, 12: 829 - 7
Radha Krishna P.Raja Sekhar E.Kannan V. Tetrahedron Lett. 2003, 44: 4973 - 8
Radha Krishna P.Kannan V.Sharma GVM.Ramana Rao MHV. Synlett 2003, 888 - 9
Yu C.Liu B.Hu L. J. Org. Chem. 2001, 66: 5413 - 10
Yu C.Hu L. J. Org. Chem. 2002, 67: 219 - 11
Kaye PT.Nocanda XW. J. Chem. Soc., Perkin Trans. 1 2000, 1331 - 12
Kaye PT.Nocanda XW. J. Chem. Soc., Perkin Trans. 1 2002, 1318
References
- For review see:
-
1a
Basavaiah D.Rao PD.Hyma RS. Tetrahedron 1996, 52: 8001 -
1b
Ciganek E. The Morita-Baylis-Hillman Reaction, In Organic Reactions Vol. 51:Paquette LA. John Wiley & Sons; New York: 1997. p.201-350 -
1c
Langer P. Angew. Chem. Int. Ed. 2000, 39: 3049 -
1d
Basavaiah D.Rao AJ.Satyanarayana T. Chem. Rev. 2003, 103: 811 - 2
Baylis AB, andHillman MED. inventors; German Patent 2155113. ; ,34174q - 3
Drewes SE.Njamela OL.Emslie ND.Ramesar N.Field JS. Synth. Commun. 1993, 23: 2807 - 4
Oishi T.Oguri H.Hirama M. Tetrahedron: Asymmetry 1995, 6: 1241 - 5
Brzezinski LJ.Rafel S.Leahy JW. J. Am. Chem. Soc. 1997, 119: 4317 - 6
Radha Krishna P.Kannan V.Ilangovan A.Sharma GVM. Tetrahedron: Asymmetry 2001, 12: 829 - 7
Radha Krishna P.Raja Sekhar E.Kannan V. Tetrahedron Lett. 2003, 44: 4973 - 8
Radha Krishna P.Kannan V.Sharma GVM.Ramana Rao MHV. Synlett 2003, 888 - 9
Yu C.Liu B.Hu L. J. Org. Chem. 2001, 66: 5413 - 10
Yu C.Hu L. J. Org. Chem. 2002, 67: 219 - 11
Kaye PT.Nocanda XW. J. Chem. Soc., Perkin Trans. 1 2000, 1331 - 12
Kaye PT.Nocanda XW. J. Chem. Soc., Perkin Trans. 1 2002, 1318