Chiral Bis(oxazolidine)pyridine–Copper-Catalyzed Enantioselective Friedel–Crafts Alkylation of Indoles with Nitroalkenes

Abstract

Catalytic asymmetric Friedel–Crafts reaction of indoles with nitroalkenes was catalyzed by the stereochemically tunable bis(oxazolidine)pyridine (PyBodine)–Cu(OTf)₂ complex. Using the PyBodine(Val)–Cu(OTf)₂ catalyst gave the Friedel–Crafts ­adducts with highly enantioselective manner. For the 1,4-bis[(E)-2-nitrovinyl]benzene, the reaction proceeded in a meso-trick manner to give the chiral double Friedel–Crafts adduct with 97% enantiomeric excess.

Key words

oxazolidine - copper - Friedel–Crafts alkylation - indole - nitroalkene - meso trick

• References and Notes

• 1 Zhou Q.-L. Privileged Chiral Ligands and Catalysts . Wiley-VCH; Weinheim: 2011
• 2 Desimoni G, Faita G, Jørgensen KA. Chem. Rev. 2006; 106: 3561
• 3a Arai T, Mizukami T, Yokoyama N, Nakazato D, Yanagisawa A. Synlett 2005; 2670
• 3b Arai T, Mizukami T, Yanagisawa A. Org. Lett. 2007; 9: 1145
• 3c Arai T, Mizukami T, Mishiro A, Yanagisawa A. Heterocycles 2008; 76: 995
• 4a Arai T, Yokoyama N, Yanagisawa A. Chem. Eur. J. 2008; 14: 2052
• 4b Arai T, Yokoyama N. Angew. Chem. Int. Ed. 2008; 47: 4989
• 4c Yokoyama N, Arai T. Chem. Commun. 2009; 3285
• 4d Arai T, Yokoyama N, Mishiro A, Sato H. Angew. Chem. Int. Ed. 2010; 49: 7895
• 4e Arai T, Awata A, Wasai M, Yokoyama N, Masu H. J. Org. Chem. 2011; 76: 5450
• 4f Awata A, Arai T. Chem. Eur. J. 2012; 18: 8278
• 4g Arai T, Yamamoto Y, Awata A, Kamiya K, Ishibashi M, Arai MA. Angew. Chem. Int. Ed. 2013; 52: 2486
• 5a Arai T, Mishiro A, Yokoyama N, Suzuki K, Sato H. J. Am. Chem. Soc. 2010; 132: 5338
• 5b Arai T, Ogino Y. Molecules 2012; 17: 6170
• 5c Arai T, Mishiro A, Matsumura E, Awata A, Shirasugi M. Chem. Eur. J. 2012; 18: 11219
• 5d Arai T, Kajikawa S, Matsumura E. Synlett 2013; 24: 2045
• 6 Arai T, Ogino Y, Sato T. Chem. Commun. 2013; 49: 7776
• 7 Nishiyama H, Sakaguchi H, Nakamura T, Horihata M, Kondo M, Itoh K. Organometallics 1989; 8: 846

Reviews of the catalytic asymmetric Friedel–Crafts reaction:
• 8a Bandini M, Melloni A, Umani-Ronchi A. Angew. Chem. Int. Ed. 2004; 43: 550
• 8b Bandini M, Melloni A, Tommasi S, Umani-Ronchi A. Synlett 2005; 1199
• 8c Poulsen TB, Jørgensen KA. Chem. Rev. 2008; 108: 2903
• 8d Bandini M, Eichholzer A. Angew. Chem. Int. Ed. 2009; 48: 9608
• 8e You S.-L, Cai Q, Zeng M. Chem. Soc. Rev. 2009; 38: 2190
• 8f Zeng M, You S.-L. Synlett 2010; 1289
• 8g Terrasson V, de Figueiredo RM, Campagne JM. Eur. J. Org. Chem. 2010; 2635
• 9a Ban Y, Murakami Y, Iwasawa Y, Tsuchiya M, Takano N. Med. Res. Rev. 1988; 8: 231
• 9b Somei M, Yamada F. Nat. Prod. Rep. 2003; 20: 216
• 9c Brancale A, Silvestri R. Med. Res. Rev. 2007; 27: 209
• 9d Higuchi K, Kawasaki T. Nat. Prod. Rep. 2007; 24: 843
• 10 Rohrer SP, Birzin ET, Mosley RT, Berk SC, Hutchins SM, Shen D.-M, Xiong Y, Hayes EC, Parmar RM, Foor F, Mitra SW, Degrado SJ, Shu M, Klopp JM, Cai S.-J, Blake A, Chan WW. S, Pasternak A, Yang L, Patchett AA, Smith RG, Chapman KT, Schaeffer JM. Science 1998; 282: 737
• 11 Christian OE, Compton J, Christian KR, Mooberry SL, Valeriote FA, Crews P. J. Nat. Prod. 2005; 68: 1592
• 12 Bandini M, Garelli A, Rovinetti M, Tommasi S, Umani-Ronchi A. Chirality 2005; 17: 522
• 13a Jia Y.-X, Zhu S.-F, Yang Y, Zhou Q.-L. J. Org. Chem. 2006; 71: 75
• 13b Lu S.-F, Du D.-M, Xu J. Org. Lett. 2006; 8: 2115
• 13c Yuan Z.-L, Lei Z.-Y, Shi M. Tetrahedron: Asymmetry 2008; 19: 1339
• 13d Lin S.-Z, You T.-P. Tetrahedron 2009; 65: 1010
• 13e Liu H, Du D.-M. Adv. Synth. Catal. 2010; 352: 1113
• 13f Liu H, Du D.-M. Eur. J. Org. Chem. 2010; 2121
• 13g McKeon SC, Müller-Bunz H, Guiry PJ. Eur. J. Org. Chem. 2011; 7107
• 13h Peng J, Du D.-M. Eur. J. Org. Chem. 2012; 4042
• 13i Jia Y, Yang W, Du D.-M. Org. Biomol. Chem. 2012; 10: 4739
• 13j Li C, Liu F.-L, Zou Y.-Q, Lu L.-Q, Chen J.-R, Xiao W.-J. Synthesis 2013; 45: 601
• 14a Singh PK, Bisai A, Singh VK. Tetrahedron Lett. 2007; 48: 1127
• 14b Sui Y, Liu L, Zhao J.-L, Wang D, Chen Y.-J. Tetrahedron 2007; 63: 5173
• 14c Wu J, Li X, Wu F, Wan B. Org. Lett. 2011; 13: 4834
• 15 Gao J.-R, Wu H, Xiang B, Yu W.-B, Han L, Jia Y.-X. J. Am. Chem. Soc. 2013; 135: 2983
• 16 Hao X.-Q, Xu Y.-X, Yang M.-J, Wang Li, Niu J.-L, Gong J.-F, Song M.-P. Organometallics 2012; 31: 835
• 17a Zhuang W, Hazell RG, Jørgensen KA. Org. Biomol. Chem. 2005; 3: 2566
• 17b Herrera RP, Sgarzani V, Bernardi L, Ricci A. Angew. Chem. Int. Ed. 2005; 44: 6576
• 17c Fleming EM, McCabe T, Connon SJ. Tetrahedron Lett. 2006; 47: 7037
• 17d Ganesh M, Seidel D. J. Am. Chem. Soc. 2008; 130: 16464
• 17e Itoh J, Fuchibe K, Akiyama T. Angew. Chem. Int. Ed. 2008; 47: 4016
• 17f Lin J.-H, Xiao J.-C. Eur. J. Org. Chem. 2011; 4536
• 17g Tang H.-Y, Zhang Z.-B. Phosphorus, Sulfur Silicon Relat. Elem. 2011; 186: 2038
• 18a Gupta AD, Bhuniya D, Singh VK. Tetrahedron 1994; 50: 13725
• 18b Ginotra SK, Singh VK. Tetrahedron 2006; 62: 3573
• 19 General Procedure of the Synthesis of PyBodine To a solution of 2,6-pyridine dicarboxyaldehyde (0.5 mmol) in CH₂Cl₂ (2 mL) was added amino alcohol (1 mmol), and the mixture was stirred at r.t. for 6 h. The resulting solution was concentrated in vacuo to afford PyBodines. Analytical Data of PyBodine(Val) (L3) ¹H NMR (400 MHz, DMSO-d ₆): δ = 8.06 (t, J = 7.6 Hz, 1 H), 7.76 (d, J = 7.6 Hz, 2 H), 7.44–7.36 (m, 8 H), 7.31–7.28 (m, 2 H), 7.23–7.19 (m, 4 H), 7.13–7.11 (m, 6 H), 5.54 (d, J = 12.5 Hz, 2 H), 3.89 (dd, J = 12.5, 3.4 Hz, 2 H), 3.75 (t, J = 12.5 Hz, 2 H), 1.92–1.85 (m, 2 H), 1.08 (d, J = 6.7 Hz, 6 H), 0.15 (d, J = 6.7 Hz, 6 H). ¹³C NMR (125 MHz, CDCl₃): δ = 155.0, 146.4, 143.8, 138.1, 128.1, 127.8, 127.6, 127.5, 127.2, 126.7, 124.6, 90.2, 88.0, 73.0, 28.6, 23.3, 16.8. ESI-FTMS: m/z calcd for C₄₁H₄₄N₃O₂ ⁺ [M + H]⁺: 610.3428; found: 610.3434. [α]_D ²⁶ –42.9 (c 1.05, CHCl₃). FTIR: 2956, 2924, 2854, 1456, 1377, 1003, 938, 813, 755, 728, 700 cm^–1.
• 20 General Procedure for the Catalytic Asymmetric Friedel–Crafts Reaction (Table 3, Entry 2) PyBodine(Val) (L3, 0.011 mmol) and Cu(OAc)₂ (0.01 mmol) were added to a round flask containing a stir bar under Ar. CH₂Cl₂ (1 mL) was added to the flask, and the mixture was stirred for 1 h. After cooling to 0 °C to the mixture was added nitroalkene (0.4 mmol), indole (0.2 mmol), and HFIP. After being stirred for appropriate time, the reaction mixture was purified by silica gel column chromatography (hexane–EtOAc; 9:1 to 2:1) to afford the Friedel–Crafts adduct. Analytical Data of 3b ¹H NMR (400 MHz, CDCl₃): δ = 7.99 (br s, 1 H), 7.36–7.30 (m, 4 H), 7.28–7.23 (m, 3 H), 7.02 (dd, J = 8.5 Hz, 1.4 Hz, 1 H) 6.96 (d, J = 1.8 Hz, 1 H), 5.16 (t, J = 8.4 Hz, 1 H), 5.05 (dd, J = 12.6, 8.4 Hz, 1 H), 4.93 (dd, J = 12.6, 8.4 Hz, 1 H), 2.17 (s, 3 H). ¹³C NMR (100 MHz, CDCl₃): δ = 139.2, 134.8, 129.3, 128.9, 127.7, 127.5, 126.3, 124.3, 121.8, 118.4, 113.9, 111.0, 79.5, 41.5, 21.5. ESI-FTMS: m/z calcd for C₁₇H₁₅N₂O₂ ^– [M – H]^–: 279.1139; found: 279.1148; the enantiomeric excess was determined by HPLC with a Chiralcel OD-H column [hexane–2-PrOH (85:15), 0.7 mL/min, 254 nm]: t _R (major enantiomer) = 50.0 min; t _R (minor enantiomer) = 71.7 min. [α]_D ²⁰ +13.5 (c 1.0, CH₂Cl₂, 87% ee). FTIR: 3412, 2974, 1556, 1377 cm^–1.
• 21a Laumen K, Schneider M. Tetrahedron Lett. 1984; 25: 5875
• 21b Wang Y.-F, Chen C.-S, Girdaukas G, Sih CJ. J. Am. Chem. Soc. 1984; 106: 3695
• 22 Analytical Data of 3l ¹H NMR (400 MHz, acetone-d ₆): δ = 10.23 (br s, 2 H), 7.51–7.46 (m, 2 H), 7.43 (s, 4 H), 7.38–7.36 (m, 4 H), 7.10–7.06 (m, 2 H), 6.97–6.93 (m, 2 H), 5.30–5.14 (m, 6 H). ¹³C NMR (100 MHz, acetone-d ₆): δ = 140.0, 137.4, 128.7, 127.0, 122.7, 122.3, 119.6, 119.2, 114.4, 112.0, 79.8, 41.5. ESI-FTMS: m/z calcd for C₂₆H₂₁N₄O₄ ^– [M – H]^–: 453.1568; found: 453.1588; the enantiomeric excess was determined by HPLC with a Chiralcel AD-H column [hexane–2-PrOH (80:20), 1.0 mL/min, 254 nm]: t _R (major enantiomer) = 44.7 min; t _R (minor enantiomer) = 48.2 min. [α]_D ²⁰ +19.0 (c 1.0, CH₂Cl₂, 97% ee). FTIR: 3412, 2921, 1546, 1457, 741 cm^–1.