Subscribe to RSS
DOI: 10.1055/s-2007-984501
Gold-Catalyzed Intermolecular Hydroamination of Allenes: First Example of the Use of an Aliphatic Amine in Hydroamination
Publication History
Publication Date:
25 June 2007 (online)
Abstract
Treatment of allenes with morpholine in the presence of cationic gold(I) catalyst in toluene at 80 °C gave the corresponding allylic amines in good to moderate yields. To the best of our knowledge, this is the first example for carrying out the gold-catalyzed intermolecular hydroamination with an aliphatic amine.
Keywords
hydroamination - gold catalyst - aliphatic amine - allenes - gold-phosphine complex
- For selected recent reviews on gold catalysis, see:
-
1a
Hoffmann-Röder A.Krause N. Org. Biomol. Chem. 2005, 3: 387 -
1b
Hashmi ASK. Angew. Chem. Int. Ed. 2005, 44: 6990 -
1c
Hashmi ASK.Hutchings GJ. Angew. Chem. Int. Ed. 2006, 45: 7896 -
1d
Jiménez-Núñez E.Echavarren AM. Chem. Commun. 2007, 333 -
1e For a recent review of gold-catalyzed hydroamination, see:
Widenhoefer RA.Han X. Eur. J. Org. Chem. 2006, 4555 - For examples of gold-catalyzed hydroamination of alkynes, see:
-
2a
Fukuda Y.Utimoto K.Nozaki H. Heterocycles 1987, 25: 297 -
2b
Fukuda Y.Utimoto K. Synthesis 1991, 975 -
2c
Müller TE.Grosche M.Herdtweck E.Pleier A.-K.Walter E.Yan Y.-K. Organometallics 2000, 19: 170 -
2d
Arcadi A.Giuseppe SD.Marinelli F.Rossi E. Adv. Synth. Catal. 2001, 343: 443 -
2e
Arcadi A.Giuseppe SD.Marinelli F.Rossi E. Tetrahedron: Asymmetry 2001, 12: 2715 -
2f
Mizushima E.Hayashi T.Tanaka M. Org. Lett. 2003, 5: 3349 -
2g
Luo Y.Li Z.Li C.-J. Org. Lett. 2005, 7: 2675 -
2h
Zhou C.-Y.Chan PWH.Che C.-M. Org. Lett. 2006, 8: 325 -
2i
Kadzimirsz D.Hildebrandt D.Merz K.Dyker G. Chem. Commun. 2006, 661 -
2j
Kang J.-E.Kim H.-B.Lee J.-W.Shin S. Org. Lett. 2006, 8: 3537 -
2k
Hashmi ASK.Rudolph M.Schymura S.Visus J.Frey W. Eur. J. Org. Chem. 2006, 4905 -
2l
Zhang Y.Donahue JP.Li C.-J. Org. Lett. 2007, 9: 627 - For examples of gold-catalyzed hydroamination of allenes, see:
-
3a
Krause N.Morita N. Org. Lett. 2004, 6: 4121 -
3b
Nishina N.Yamamoto Y. Angew. Chem. Int. Ed. 2006, 45: 3314 -
3c
Patil NT.Lutete LM.Nishina N.Yamamoto Y. Tetrahedron Lett. 2006, 47: 4749 -
3d
Zhang Z.Liu C.Kinder RE.Han X.Qian H.Widenhoefer RA. J. Am. Chem. Soc. 2006, 128: 9066 -
3e
Morita N.Krause N. Eur. J. Org. Chem. 2006, 4634 -
3f
LaLonde RL.Sherry BD.Kang EJ.Toste FD. J. Am. Chem. Soc. 2007, 129: 2452 - For examples of gold-catalyzed hydroamination of alkenes, see:
-
4a
Zhang J.Yang C.-G.He C. J. Am. Chem. Soc. 2006, 128: 1798 -
4b
Brouwer C.He C. Angew. Chem. Int. Ed. 2006, 45: 1744 -
4c
Han X.Widenhoefer RA. Angew. Chem. Int. Ed. 2006, 45: 1747 -
4d
Liu X.-Y.Li C.-H.Che C.-M. Org. Lett. 2006, 8: 2707 -
4e
Shi M.Liu L.-P.Tang J. Org. Lett. 2006, 8: 4043 -
4f
Bender CF.Widenhoefer RA. Chem. Commun. 2006, 4143 -
4g
Bender CF.Widenhoefer RA. Org. Lett. 2006, 8: 5303 - For examples of cationic gold(I)-catalyzed addition of carbon nucleophiles, see:
-
5a
Kennedy-Smith JJ.Staben ST.Toste FD. J. Am. Chem. Soc. 2004, 126: 4526 -
5b
Staben ST.Kennedy-Smith JJ.Toste FD. Angew. Chem. Int. Ed. 2004, 43: 5350 -
5c
Mézailles N.Ricard L.Gagosz F. Org. Lett. 2005, 7: 4133 -
5d
Ochida A.Ito H.Sawamura M. J. Am. Chem. Soc. 2006, 128: 16486 -
5e
Wei C.Li C.-J. J. Am. Chem. Soc. 2003, 125: 9584 -
5f
Yao X.Li C.-J. Org. Lett. 2006, 8: 1953 - For some recent reviews of enyne cyclization, see:
-
5g
Ma S.Yu S.Gu Z. Angew. Chem. Int. Ed. 2006, 45: 200 -
5h
Nieto-Oberhuber C.López S.Jiménez-Núñez E.Echavarren AM. Chem. Eur. J. 2006, 12: 5917 -
5i
Zhang L.Sun J.Kozmin SA. Adv. Synth. Catal. 2006, 348: 2271 - For examples of cationic gold(I)-catalyzed addition of oxygen nucleophiles, see:
-
6a
Teles JH.Brode S.Chabanas M. Angew. Chem. Int. Ed. 1998, 37: 1415 -
6b
Mizushima E.Sato K.Hayashi T.Tanaka M. Angew. Chem. Int. Ed. 2002, 41: 4563 -
6c
Liu Y.Song F.Song Z.Liu M.Yan B. Org. Lett. 2005, 7: 5409 -
6d
Yang C.-G.He C. J. Am. Chem. Soc. 2005, 127: 6966 -
6e
Belting V.Krause N. Org. Lett. 2006, 8: 4489 -
6f
Liu B.Brabander KD. Org. Lett. 2006, 8: 4907 -
6g
Zhang Z.Widenhoefer RA. Angew. Chem. Int. Ed. 2007, 46: 283 - 7 For an example of cationic gold(I)-catalyzed addition of nitrogen nucleophiles, see:
Gorin DJ.Davis NR.Toste FD. J. Am. Chem. Soc. 2005, 127: 11260 -
9a
Wabnitz TC.Spencer JB. Org. Lett. 2003, 5: 2141 -
9b
Li Z.Zhang J.Brouwer C.Yang C.-G.Reich NW.He C. Org. Lett. 2006, 8: 4175 -
9c
Rosenfeld DC.Shekhar S.Takeymiya A.Utsunomiya M.Hartwig JF. Org. Lett. 2006, 8: 4179 -
9d
Lapis AAM.Neto BAD.Scholten JD.Nachtigall FM.Eberlin MN.Dupont J. Tetrahedron Lett. 2006, 47: 6775 - 10 In order to know whether the cationic gold species really participate in the present hydroamination or not, we prepared the cationic gold species [(MeCN)AuPPh2(o-tolyl)]+
-OTf according to the Echavarren’s method and used it for the hydroamination of 1a. The product 3a was obtained in 71% yield, indicating that the cationic gold complex was a catalytic species. See:
Nieto-Oberhuber C.López S.Muñoz MP.Cárdenas DJ.Buñuel E.Nevado C.Echavarren AM. Angew. Chem. Int. Ed. 2005, 44: 6146 - 11 It is reported that manipulation of phosphine ligands enhances the chemical yield in Pd-catalyzed amination of aryl halides. See:
Chen G.Lam WH.Fok WS.Lee HW.Kwong FY. Chem. Asian J. 2007, 2: 306 - 12
Alcock NW.Moore P.Lampe PA.Mok KF. J. Chem. Soc., Dalton Trans. 1982, 207 - 14
General Procedure for Preparation of Catalysts
These complexes were prepared following a literature procedure, and characterized by comparison of the NMR data with literature values, except for 4c, 4d, and 4h. A solution of SMe2 (1.2 mL, 16 mmol) in MeOH (6 mL) was added to a solution of NaAuCl4·2H2O (2.19 g, 5.5 mmol) in MeOH (30 mL) with minimum light exposure. The white precipitate was recovered by filtration, washed (MeOH, Et2O, and pentane), and dried under vacuum. Then, [AuCl(SMe2)] was obtained in 99% yield (1.60 g) and used without further purification. 1H NMR (300 MHz, CDCl3): δ = 2.73 (s, 6 H). A solution of diphenyl(o-tolyl)phosphine (0.589 g, 2 mmol) in acetone (50 mL) was added to a solution of [AuCl(SMe2)] (0.553 g) in acetone (150 mL). The mixture was stirred for 2 h and concentrated, recrystallized from toluene, and dried under vacuum; [AuClPPh2(o-Me-C6H4)](4h) was obtained in 83% (0.83 g). See:
Brandys M.-C.Jennings MC.Puddephatt RJ. J. Chem. Soc., Dalton Trans. 2000, 4601
References and Notes
We examined the following complexes, but all attempts resulted in failure: AuCl, AuCl3, AuBr3, AuI, Au(CO)Cl, NaAuCl4·2H2O. It is known that the hydroamination of olefins with tosylamides is accelerated by TfOH, [9] so we examined the TfOH-catalyzed (10 mol%) hydroamination of 1a with 2 in toluene at 80 °C. However, the desired product (allylic amine) was not obtained at all. The allene 1a was decomposed gradually in the presence of TfOH at 80 °C, and only 30% of 1a was recovered after 12 h. It is clear that the present hydroamination is catalyzed by the gold complexes.
13This reaction could not be checked by TLC nor GC-MS, because of its low boiling point (ca. 80 °C). Thus, reactions were stopped at 24 h.
15ClAuPPh2(o-MeOC6H4)(4c): 1H NMR (600 MHz, CDCl3): δ = 3.71 (3 H, s), 6.82 (1 H, ddd, J = 13.2, 7.8, 1.8 Hz), 6.97 (1 H, dd, J = 8.4, 5.1 Hz), 6.93-6.97 (1 H, m), 7.42-7.47 (4 H, m), 7.49-7.57 (7 H, m). 13C NMR (75.5 Hz, CDCl3): δ = 55.9, 111.6 [d, J(13C-31P) = 4.1 Hz], 116.4 [d, J(13C-31P) = 57.0 Hz], 121.1 [d, J(13C-31P) = 10.8 Hz], 128.4, 128.9 [d, J(13C-31P) = 11.6 Hz], 131.5 [d, J(13C-31P) = 2.5 Hz], 133.9 [d, J(13C-31P) = 1.7 Hz], 134.0 [d, J(13C-31P) = 14.9 Hz], 134.2 [d, J(13C-31P) = 7.5 Hz], 160.7 [d, J(13C-31P) = 5.0 Hz]. 31P NMR (121.5 Hz, CDCl3): δ = 25.0. IR (neat, ATR): 1584, 1572, 1473, 1459, 1435, 1278, 1247, 1101, 1011, 764, 747 cm-1. Anal. Calcd for C19H17AuClOP: C, 43.49; H, 3.27; Cl, 6.76. Found: C, 43.62; H, 3.32; Cl, 6.75. ESI-HRMS: m/z calcd for C19H17AuClOP [M + Na]: 547.0263; found: 547.0267.
ClAuPPh2(p-F3CC6H4) (4d): 1H NMR (600 MHz, CDCl3): δ = 7.48-7.60 (10 H, m), 7.64 (2 H, dd, J = 12.6, 7.8 Hz), 7.72 (2 H, dd, J = 7.8, 1.5 Hz). 13C NMR (75.5 Hz, CDCl3): δ = 121.4 [d, J(13C-31P) = 1.2 Hz], 126.0 [dq, J(13C-31P) = 11.8 Hz, J(13C-19F) = 3.7 Hz], 126.7 [q, J(13C-19F) = 81.3 Hz], 128.0, 129.5 [d, J(13C-31P) = 11.8 Hz], 132.4 [d, J(13C-31P) = 2.5 Hz], 134.2 [d, J(13C-31P) = 8.8 Hz], 134.3 [d, J(13C-31P) = 14.3 Hz]. 31P NMR (121.5 Hz, CDCl3): δ = 33.3. IR (neat, ATR): 1436, 1395, 1322, 1125, 1103, 1061, 1014, 838, 748, 708 cm-1. ESI-HRMS: m/z calcd for C19H14AuClF3P [M + Na]: 585.0031; found: 585.0032.
ClAuPPh2(o-MeC6H4) (4h): 1H NMR (600 MHz, CDCl3): δ = 2.53 (3 H, s), 6.74 (1 H, ddd, J = 12.7, 7.7, 1.2 Hz), 7.18 (1 H, dd, J = 7.5, 7.5 Hz), 7.29-7.33 (1 H, m), 7.43 (1 H, ddd, J = 7.5, 7.5, 1.4 Hz), 7.46-7.51 (4 H, m), 7.53-7.60 (6 H, m). 13C NMR (75.5 Hz, CDCl3): δ = 22.6 [d, J(13C-31P) = 12.2 Hz], 126.3 [d, J(13C-31P) = 10.0 Hz], 126.8 [d, J(13C-31P) = 60.2 Hz], 128.0 [d, J(13C-31P) = 63.8 Hz], 129.4 [d, J(13C-31P) = 12.2 Hz], 131.8 [d, J(13C-31P) = 2.2 Hz], 132.0 [d, J(13C-31P) = 9.3 Hz], 132.1 [d, J(13C-31P) = 2.2 Hz], 133.0 [d, J(13C-31P) = 8.6 Hz], 134.5 [d, J(13C-31P) = 14.3 Hz], 142.0 [d, J(13C-31P) = 12.2 Hz]. 31P NMR (121.5 Hz, CDCl3): δ = 32.1. IR (neat, ATR): 1589, 1479, 1436, 1101, 997, 804, 751, 714 cm-1. Anal. Calcd for C19H17AuClP: C, 44.86; H, 3.37; Cl, 6.97. Found: C, 45.00; H, 3.60; Cl, 6.93. ESI-HRMS: m/z calcd for C19H17AuClP [M + Na]: 531.0314; Found: 531.0314.
1H, 13C, and 31P NMR chemical shifts are reported relative to CDCl3 and 85% H3PO4.
General Procedure for Hydroamination of Allenes
To a suspension of [AuClPPh2(o-tolyl)] (25.4 mg, 0.05 mmol) in toluene (0.5 mL) was added morpholine (43.7 mg, 0.502 mmol). To the reaction mixture was added 4-methyl-phenylallene (1a, 79.3 mg, 0.6 mmol) and the resulting mixture was stirred at 80 °C under an Ar atmosphere. The reaction mixture was colorless and heterogeneous at the beginning, but it turned yellow to brown as the reaction progressed. After the reaction was completed (12 h), the reaction mixture was filtered through short Florisil® gel pad with EtOAc as an eluent and the resulting filtered solution was concentrated. The product was purified by column chromatography (basic silica gel, hexane-EtOAc = 100:1 to 10:1) to give 3a in 83% yield (90.8 mg).
(E)-4-(3-p-Tolylallyl)morpholine (3a): 1H NMR (300 MHz, CDCl3): δ = 2.31 (3 H, s), 2.40-2.59 (4 H, m), 3.12 (2 H, dd, J = 6.8, 1.3 Hz), 3.72 (4 H, dd, J = 4.7, 4.7 Hz), 6.18 (1 H, dt, J = 15.8, 6.8 Hz), 6.48 (1 H, d, J = 15.8 Hz), 7.10 (2 H, d, J = 8.1 Hz), 7.25 (2 H, d, J = 8.1 Hz). 13C NMR (75.5 Hz, CDCl3): δ = 21.2, 53.7, 61.5, 67.0, 124.9, 126.2, 129.3, 133.3, 134.0, 137.4. IR (neat): 1712, 1512, 1452, 1116, 1006, 968, 869, 809, 776 cm-1. HRMS (EI): m/z calcd for C14H19NO [M+]: 217.1462; found: 217.1464.
4-Cinnamylmorpholine (3b): 1H NMR (300 MHz, CDCl3): δ = 2.45 (4 H, dd, J = 4.6, 4.6 Hz), 3.10 (2 H, dd, J = 6.8, 1.3 Hz), 3.68 (4 H, dd, J = 4.6, 4.6 Hz), 6.19 (1 H, dt, J = 15.8, 6.8 Hz), 6.47 (1 H, d, J = 15.8 Hz), 7.11-7.38 (5 H, m). 13C NMR (75.5 Hz, CDCl3): δ = 53.7, 61.5, 66.9, 125.8, 126.3, 127.6, 128.6, 133.5, 136.7. IR (neat): 1598, 1496, 1451, 1277, 1115, 1006, 966, 868, 741 cm-1. HRMS (EI): m/z calcd for C13H17NO [M+]: 203.1305; found: 203.1308.
(E)-4-(4-Phenylbut-2-enyl)morpholine (3c): 1H NMR (300 MHz, CDCl3): δ = 2.30-2.54 (4 H, m), 2.95 (2 H, dd, J = 6.6, 0.9 Hz), 3.36 (2 H, d, J = 6.6 Hz), 3.70 (4 H, dd, J = 4.8, 4.8 Hz), 5.54 (1 H, dtt, J = 15.2, 6.6, 1.3 Hz), 5.76 (1 H, dtt, J = 15.2, 6.6, 1.3 Hz), 7.11-7.23 (3 H, m), 7.23-7.33 (2 H, m). 13C NMR (75.5 Hz, CDCl3): δ = 38.9, 53.5, 61.1, 67.0, 126.1, 127.3, 128.4, 128.5, 133.4, 140.2. IR (neat): 1603, 1495, 1453, 1116, 1003, 975, 865, 745 cm-1. HRMS (EI): m/z calcd for C14H19NO [M+]: 217.1462; found: 217.1464.
(E)-4-(Undec-2-enyl)morpholine (3d): 1H NMR (300 MHz, CDCl3): δ = 0.81 (3 H, t, J = 6.6 Hz), 1.03-1.43 (12 H, m), 1.95 (2 H, dt, J = 7.0, 6.6 Hz), 2.26-2.48 (4 H, m), 2.86 (2 H, d, J = 6.6 Hz), 3.65 (4 H, dd, J = 4.6, 4.6 Hz), 5.39 (1 H, dt, J = 15.2, 6.6 Hz), 5.54 (1 H, dt, J = 15.2, 6.6 Hz). 13C NMR (75.5 Hz, CDCl3): δ = 14.1, 22.7, 29.2, 29.2, 29.3, 29.4, 31.9, 32.3, 53.5, 61.4, 67.0, 125.6, 135.3. IR (neat): 1720, 1454, 1004, 972, 867 cm-1. HRMS (EI): m/z calcd for C15H29NO [M+]: 239.2244; found: 239.2246.
(E)-4-(3-Cyclohexylallyl)morpholine (3e): 1H NMR (300 MHz, CDCl3): δ = 0.98-1.31 (5 H, m), 1.55-1.85 (5 H, m), 1.85-2.03 (1 H, m), 2.34-2.55 (4 H, m), 2.93 (2 H, d, J = 6.8 Hz), 3.71 (4 H, dd, J = 4.7, 4.7 Hz), 5.40 (1 H, dtd, J = 15.4, 6.6, 0.9 Hz), 5.55 (1 H, dd, J = 15.4, 6.6 Hz). 13C NMR (75.5 Hz, CDCl3): δ = 26.0, 26.1, 32.9, 40.5, 53.5, 61.5, 67.0, 123.0, 141.1. IR (neat): 1718, 1449, 1118, 1005, 971, 866 cm-1. HRMS (EI): m/z calcd for C13H23NO [M+]: 209.1775; found: 209.1779.
(E)-4-(4,4-Dimethylpent-2-enyl)morpholine (3f): 1H NMR (300 MHz, CDCl3): δ = 0.94 (9 H, s), 2.27-2.44 (4 H, m), 2.87 (2 H, dd, J = 6.8, 1.0 Hz), 3.66 (4 H, dd, J = 4.7, 4.7 Hz), 5.32 (1 H, dt, J = 15.6, 6.8 Hz), 5.56 (1 H, d, J = 15.6 Hz). 13C NMR (75.5 Hz, CDCl3): δ = 29.6, 29.7, 53.5, 61.5, 67.0, 120.3, 146.2. IR (neat): 1732, 1454, 1260, 1119, 1005, 975, 868 cm-1. ESI-HRMS: m/z calcd for C11H21NO [M + H]: 184.1696; found: 184.1696.
(E)-4-(4-Phenylbut-3-en-2-yl)morpholine (3g): 1H NMR (300 MHz, CDCl3): δ = 1.24 (3 H, d, J = 6.6 Hz), 2.54 (4 H, dt, J = 4.8, 4.4 Hz), 3.00 (2 H, dq, J = 8.1, 6.6 Hz), 3.71 (4 H, dd, J = 4.4, 4.4 Hz), 6.15 (1 H, dt, J = 15.8, 8.1 Hz), 6.44 (1 H, d, J = 15.8 Hz), 7.14-7.42 (5 H, m). 13C NMR (75.5 Hz, CDCl3): δ = 17.8, 50.8, 63.1, 67.2, 126.2, 127.5, 128.6, 131.2, 132.1, 136.9. IR (neat): 1600, 1494, 1447, 1265, 1116, 963, 864, 747 cm-1. HRMS (EI): m/z calcd for C14H19NO [M+]: 217.1462; found: 217.1465.
(E)-4-(1-Phenylbut-2-enyl)morpholine (3g′): 1H NMR (300 MHz, CDCl3): δ = 1.59 (3 H, dd, J = 6.0, 1.1 Hz), 2.15-2.31 (2 H, m), 2.33-2.56 (2 H, m), 3.48 (1 H, d, J = 8.6 Hz), 3.61 (4 H, dd, J = 4.4, 4.4 Hz), 5.45 (1 H, ddd, J = 15.0, 8.6, 1.1 Hz), 5.58 (1 H, dq, J = 15.0, 6.0 Hz), 7.11-7.31 (5 H, m). 13C NMR (75.5 Hz, CDCl3): δ = 17.8, 52.0, 67.2, 74.6, 127.0, 127.7, 127.9, 128.5, 132.7, 142.3. IR (neat): 1492, 1449, 1271, 1116, 1003, 967, 875, 755 cm-1. ESI-HRMS: m/z calcd for C14H19NO [M + H]: 218.1539; found: 218.1539.
4-(3-Phenylbut-2-enyl)morpholine (3h): inseparable stereoisomeric mixture. 1H NMR (300 MHz, CDCl3): δ = 2.05 (E- and Z-3 H, s), 2.25-2.42 (Z-4 H, m), 2.44-2.60 (E-4 H, m), 2.91 (Z-2 H, d, J = 6.8 Hz), 3.17 (E-2 H, d, J = 6.8 Hz), 3.70 (Z-4 H, dd, J = 4.6, 4.6 Hz), 3.72 (E-4 H, dd, J = 4.6, 4.6 Hz), 5.55 (Z-1 H, td, J = 6.8, 1.3 Hz), 5.86 (E-1 H, td, J = 6.8, 1.3 Hz), 7.09-7.45 (E- and Z-5 H, m).
NOE Experiment for 3h: Two signals were observed by irradiation for Me peak (δ = 2.05 ppm); 0.52% for allyl-H peak of E-isomer (δ = 3.17 ppm) and 1.64% for vinyl-H peak of Z-isomer (δ = 5.55 ppm). From this experiment, we determined that the major product was E-isomer and the E:Z ratio was 5: 4.