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DOI: 10.1055/s-0030-1258525
A Novel Indium-Catalyzed Three-Component Reaction: General and Efficient One-Pot Synthesis of Substituted Pyrroles
Publication History
Publication Date:
27 July 2010 (online)
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Abstract
A convenient and general approach towards the synthesis of substituted pyrroles from propargylic acetates, silyl enol ethers, and primary amines was described. This novel transformation was catalyzed by indium trichloride in a one-pot synthesis, and high yields of various pyrrole derivatives were obtained.
Key words
pyrrole - indium - one-pot reaction - propargylic acetate - enoxysilane
- Supporting Information for this article is available online:
- Supporting Information
- For recent reviews and selected examples, see:
-
1a
Fan H.Peng J.Hamann MT.Hu JF. Chem. Rev. 2008, 108: 264 -
1b
Novak P.Müller K.Santhanam KSV.Haas O. Chem. Rev. 1997, 97: 207 -
1c
D’Souza DM.Müller TJJ. Chem. Soc. Rev. 2007, 36: 1095 -
1d
Balme G.Bouyssi D.Monteiro N. Heterocycles 2007, 73: 87 -
1e
Cadierno V.Crochet P. Curr. Org. Synth. 2008, 5: 343 -
1f
Hughes CC.Prieto-Davo A.Jensen PR.Fenical W. Org. Lett. 2008, 10: 629 -
1g
Bellina F.Rossi R. Tetrahedron 2006, 62: 7213 -
1h
Butler MS. J. Nat. Prod. 2004, 67: 2141 -
1i
Balme G. Angew. Chem. Int. Ed. 2004, 43: 6238 -
1j
Fürstner A. Angew. Chem. Int. Ed. 2003, 42: 3582 -
1k
Fürstner A.Weintritt H. J. Am. Chem. Soc. 1998, 97: 207 - 2
Joule JA.Mills K. In Heterocyclic Chemistry 4th ed.: Blackwell Science; Oxford: 2000. p.237 - For recent reviews and selected examples, see:
-
3a
Patil NT.Yamamoto Y. Chem. Rev. 2008, 108: 3395 -
3b
Eloisa J.Echavarren AM. Chem. Rev. 2008, 108: 3326 -
3c
Álvarez-Corral M.Muñoz-Dorado M.Rodríguez-Garcia I. Chem. Rev. 2008, 108: 3174 -
3d
Weibe J.Blanc A.Pale P. Chem. Rev. 2008, 108: 3149 -
3e
Kel’in AV.Stromek AW.Gevorgyan V. J. Am. Chem. Soc. 2001, 123: 2074 -
3f
Chernyak D.Gadamsetty SB.Gevorgyan V. Org. Lett. 2008, 10: 2307 -
4a
Ji W.Pan Y.Zhao S.Zhan Z. Synlett 2008, 3046 -
4b
Liu X.Huang L.Zheng F.Zhan Z. Adv. Synth. Catal. 2008, 350: 2778 -
4c
Zhan Z.Yu J.Liu H.Cui Y.Yang R.Yang W.Li J. J. Org. Chem. 2006, 71: 8298 - For selected examples for In-catalyzed heterocyclic synthesis via cycloisomerization, see:
-
5a
Feng X.Tan Z.Chen D.Shen Y.Guo C.Xiang J.Zhu C. Tetrahedron Lett. 2008, 49: 4110 -
5b
Kim SH.Kim SH.Kim KH.Kim JM. Tetrahedron Lett. 2010, 51: 860 - 6
Zhan Z.Cai X.Wang S.Yu J.Liu H.Cui Y. J. Org. Chem. 2007, 72: 9838
References and Notes
General Experimental
Methods
Propargylic acetates 1 and
enoxysilanes 2 were prepared according
to published procedures. All other compounds are commercially available
and were used without further purification. Infrared spectra were
recorded on a Nicolet AVATER FTIR360 spectrometer. NMR spectra were recorded
on a Bruker AVANCE DPX-400 instrument at 400 MHz (¹H)
or 100 MHz (¹³C). The chemical shift
values (δ) are given in parts per million(ppm) and are
referred to the residual peak of the deuterated solvent (CDCl3).
MS measurements were performed on Bruker Reflex III mass spectrometer.
Elemental analyses were performed with a PerkinElmer 2400 microanalyser.
Flash chromatography was performed with QingDao silica gel (300-400
mesh).
A Representative
Procedure for the Synthesis of Substituted Pyrrole 2-Benzyl-1,3,5-triphenyl-1
H
-pyrrole (6aa)
To a 10 mL flask, propargylic
acetate 1a (0.5 mmol), enoxysilane 2a (1.0 mmol), chlorobenzene (2.0 mL),
and InCl3 (0.05 mmol) were successively added. The reaction was
allowed to stir at 75 ˚C for 0.5 h, followed by adding primary
amines 7a (1.0 mmol). The reaction mixture
was heated to keep refluxing for an additional 1 h until completion
(monitored by TLC). Upon cooling to r.t., the reaction mixture was
then quenched with 1 M HCl (2 mL). The organic and aqueous layers
were separated, and the latter was extracted with Et2O
(3 × 5 mL). The combined organic layers
were dried over MgSO4 and filtered. The filtrate was
concentrated in vacuo, and then the residue was purified by silica
gel column chromatography (EtOAc-hexane, 1:100)
to afford the corresponding substituted pyrroles. A yellow solid,
mp 146-147 ˚C; yield 87% (0.167 g). ¹H
NMR (400 MHz, CDCl3): δ = 7.50-7.52
(m, 2 H), 7.33-7.37 (m, 2 H), 7.07-7.24 (m, 12
H), 6.95-6.97 (m, 2 H), 6.88-6.90 (m, 2 H), 6.66
(s, 1 H), 4.04 (s, 2 H) ppm.
¹³C
NMR (100 MHz, CDCl3): δ = 140.5,
139.1, 136.9, 134.8, 133.2, 130.2, 129.0, 128.8, 128.7, 128.3, 128.2, 128.1,
128.0, 127.7, 126.1, 125.9 (3), 124.4, 109.6, 31.5 ppm. IR (film):
1493, 1599, 3024 cm-¹. ESI-MS: m/z (%) = 386
(100) [M + H+]. Anal.
Calcd (%) for C29H23N: C, 90.35; H,
6.01; N, 3.63. Found: C, 90.38; H, 6.00, N, 3.63.