RSS-Feed abonnieren
DOI: 10.1055/s-2006-941587
Dimethylaminomethylphosphonic Acid Derivatives-Promoted CuI-Catalyzed Synthesis of Aryl Ethers
Publikationsverlauf
Publikationsdatum:
12. Juni 2006 (online)
![](https://www.thieme-connect.de/media/synlett/200610/lookinside/thumbnails/10.1055-s-2006-941587-1.jpg)
Abstract
An inexpensive and efficient catalyst system for synthesis of aryl ethers has been developed by using 20 mol% CuI as the catalyst, 30 mol% dimethylaminomethylphosphonic acid derivatives as the new ligands, K2CO3 as the base and toluene as the solvent. This is the first example using aminophosphonates as the ligands for Ullmann ether coupling reaction.
Key words
Ullmann reaction - aryl ether - copper-catalyzed - dimethylaminomethylphosphonic acid derivative
-
1a
Evans DA.DeVries KM. In Glycopeptide Antibiotics, Drugs and the Pharmaceutical Sciences Vol. 63:Nagarajan R. Marcel Decker, Inc.; New York: 1994. p.63-104 -
1b
Theil F. Angew. Chem. Int. Ed. 1999, 38: 2345 -
1c
Itokama H.Takeya K. Heterocycles 1993, 35: 1467 -
1d
Kase H.Masami K.Yamada K. J. Antibiot. 1987, 40: 450 -
1e
Williams DH. Acc. Chem. Res. 1984, 17: 364 -
1f
Pearson AJ.Bignan G.Zhang P.Chelliah M. J. Org. Chem. 1996, 61: 3940 -
1g
Janetka JW.Raman P.Satyshur K.Flentke GR.Rich DH. J. Am. Chem. Soc. 1997, 119: 441 -
1h
Nicolaou KC.Boddy CNC.Natarajan S.Yue T.-Y.Li H.Bräse S.Ramanjulu JM. J. Am. Chem. Soc. 1997, 119: 3421 -
1i
Boger DL.Patane MA.Zhou J. J. Am. Chem. Soc. 1994, 116: 8544 - 2
Ullmann F. Ber. Dtsch. Chem. Ges. 1904, 37: 853 - 3
Lindley J. Tetrahedron 1984, 40: 1433 - For palladium-mediated ether synthesis, see:
-
4a
Torraca KE.Huang X.Parrish CA.Buchwald SL. J. Am. Chem. Soc. 2002, 123: 10770 -
4b
Aranyos A.Old DW.Kiyomori A.Wolfe JP.Sadighi JP.Buchwald SL. J. Am. Chem. Soc. 1999, 121: 4369 -
4c
Mann G.Hartwig JF. Tetrahedron Lett. 1997, 38: 8005 -
4d
Mann G.Incarvito C.Rheigold AL.Hartwig JF. J. Am. Chem. Soc. 1999, 121: 3224 -
4e
Shelby Q.Kataoka N.Mann G.Hartwig J. J. Am. Chem. Soc. 2000, 122: 10718 - For some recent reports, see:
-
5a
Marcoux J.-F.Doye S.Buchwald SL. J. Am. Chem. Soc. 1997, 119: 10539 -
5b
Buck E.Song ZJ.Tschaen D.Dormer PG.Volante RP.Reider PJ. Org. Lett. 2002, 4: 1623 -
5c
Palomo C.Oiarbide M.Lopez R.Gomez-Bengoa E. Chem. Commun. 1998, 2091 -
5d
Ma D.Cai Q. Org. Lett. 2003, 5: 3799 -
5e
Fagan PJ.Hauptman E.Shapiro R.Casalnuovo A. J. Am. Chem. Soc. 2000, 122: 5043 -
5f
Gujadhur RK.Bates CG.Venkataraman D. Org. Lett. 2001, 3: 4135 -
5g
Cristau HJ.Cellier PP.Hamada S.Spindler JF.Tailefer M. Org. Lett. 2004, 6: 913 -
6a
Hardy TA. inventors; US Patent 4083897. -
6b
Diel PJ.Maier L. Phosphorus Sulfur Relat. Elem. 1984, 20: 13 - 9
Antilla JC.Klapars A.Buchwald SL. J. Am. Chem. Soc. 2002, 124: 11684
References and Notes
Synthesis of Diisopropyl Dimethylaminomethyl-phosphonate (L
¹
).
The mixed solution of diisopropyl phosphite (22 mmol, 3.7 g), dimethylamine hydrochloride (22 mmol, 1.79 g) and Et3N (22 mmol, 3.2 mL) in EtOH (30 mL) was added dropwise to 37% aq formaldehyde (1.8 mL), and the resulting solution was refluxed for 8 h. The 31P NMR spectroscopy showed that the starting material diisopropyl phosphite was almost quantitatively transferred into ligand L
¹
(δ = 26.9 ppm). The solvent was removed by rotary evaporation, the residue was isolated by silica gel column chromatography using CHCl3-MeOH (10:1) as eluent, and the pure L
¹
was obtained as a colorless liquid. Yield 4.50 g, 92%. 31P NMR (121.5 MHz, CDCl3): δ = 26.9 ppm. 1H NMR (300 MHz, CDCl3): δ = 4.78-4.71 (m, 2 H), 2.75 (d, J = 20.4 Hz, 2 H), 1.33 (s, 6 H), 2.41-2.38 (m, 12 H). 13C NMR (75 MHz, CDCl3): δ = 70.2, 56.9, 47.4, 24.0. ESI-HRMS: m/z calcd for C9H23NO3P [M + H]+: 224.1416; found: 224.1411.
Synthesis of Ethyl Dimethylaminomethylphosphonate (L
²
).
The mixed solution of diethyl phosphite (22 mmol, 3.0 g), dimethylamine hydrochloride (22 mmol, 1.79 g) in EtOH (30 mL) was added dropwise to 37% aq formaldehyde (1.8 mL), and the resulting solution was refluxed for 6 h. The solvent was removed by rotary evaporation, the residue was dissolved in 5 mL of H2O and 10 mL of EtOH. Then, LiOH (22 mmol, 0.53 g) was added, and the solution was stirred at 60 °C for 3 h. The solution was extracted with CH2Cl2, the aqueous phase was acidified with 3 M HCl to pH 3, and evaporated to dryness to provide a solid mixture. MeOH was added to the remaining solid, and the insoluble solid was filtrated. The filtrate was concentrated and dried over P2O5 in vacuo, and the desired product ethyl dimethylamino-methylphosphonate hydrochloride salt (L
²
) was obtained in the form of a white solid. Yield 3.81 g, 85%. 31P NMR (121.5 MHz, CDCl3): δ = 6.8 ppm. 1H NMR (300 MHz, CDCl3): δ = 8.98 (s, 1 H), 3.71-3.61 (m, 2 H), 2.80 (d, J = 20.4 Hz, 2 H), 2.59 (s, 6 H), 0.95 (t, J = 7.0 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 60.5, 55.2, 55.3, 45.3, 16.7. ESI-HRMS: m/z calcd for C5H15NO3P [M + H]+: 168.0790; found: 168.0783.
Synthesis of Dimethylaminomethylphosphonic Acid (L
³
).
This compound was synthesized according to the known method.2 Dimethylamine hydrochloride (50 mmol, 4.2 g), H3PO4 (50 mmol, 4.1 g) and 20 mL of HCl (6.5 M in H2O) were added to a round-bottom flask fitted with a reflux condenser, and the solution was heated for 5 min. Then, 52 mmol (3.87 mL) of formaldehyde (36% aq solution) was added, and the solution was refluxed for 90 min. After removal of H2O in vacuo, the residue was heated in 60 mL of EtOH to lead to the formation of a white solid. This solid was collected after filtration, and dried in vacuo to obtain dimethylaminomethyl phosphonic acid hydrochloride salt (L
³
, 8.42 g, 96%). 31P NMR (121.5 MHz, DMSO-d
6,): δ = 9.3 ppm. 1H NMR (300 MHz, DMSO-d
6): δ = 5.86 (s, 2 H), 3.30 (d, J = 12.7 Hz, 2 H), 2.83 (s, 6 H). 13C NMR (75 MHz, DMSO-d
6): δ = 54.7, 52.8, 44.8. ESI-HRMS: m/z calcd for C3H11NO3P [M + H]+: 140.0477; found: 140.0481.
Characterization data of two representative compounds are shown as follows:
4-Nitrophenyl Phenyl Ether (3j)
9
Yellow solid; mp 58-60 °C (Lit.7 60 °C). 1H NMR (300 MHz, CDCl3): δ = 8.17 (d, J = 9.27 Hz, 2 H), 7.42 (t, J = 7.89 Hz, 2 H), 7.25 (t, J = 7.56 Hz, 1 H), 7.08 (d, J = 7.82 Hz, 2 H), 7.00 (d, J = 8.85 Hz, 2 H). 13C NMR (75 MHz, CDCl3): δ = 163.5, 154.8, 142.7, 130.4, 126.0, 125.5, 120.6, 117.2. HRMS (EI): m/z calcd for C12H9NO3 [M+]: 215.0582; found: 215.0574.
Bis(4-methoxyphenenyl)ether (3m)
5b
White solid; mp 101-103 °C (Lit.5b 102-103 °C). 1H NMR (300 MHz, CDCl3): δ = 6.92 (d, J = 9.27 Hz, 4 H), 6.85 (d, J = 9.27 Hz, 4 H), 3.79 (s, 3 H). 13C NMR (75 MHz, CDCl3): δ = 155.4, 151.7, 119.6, 114.8, 55.8. HRMS (EI): m/z calcd for C14H14O3 [M+]: 230.0943; found: 230.0949.