Synlett 2017; 28(18): 2396-2400
DOI: 10.1055/s-0036-1588442
cluster
© Georg Thieme Verlag Stuttgart · New York

Boron-Catalyzed Hydrogenative Reduction of Substituted Quinolines to Tetrahydroquinolines with Hydrosilanes

Narasimhulu Gandhamsettya, b, Sehoon Park*a, b, Sukbok Chang*a, b
  • aCenter for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 305-701, South Korea
  • bDepartment of Chemistry, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 305-701, South Korea   Email: sehoonp@kaist.ac.kr   Email: sbchang@kaist.ac.kr
This research was supported by the Institute for Basic Science (IBS-R010-D1) in Korea.
Further Information

Publication History

Received: 30 March 2017

Accepted after revision: 09 May 2017

Publication Date:
23 May 2017 (eFirst)

Published as part of the Cluster Silicon in Synthesis and Catalysis

Abstract

A metal-free procedure for the hydrogenative reduction of substituted N-heteroaromatics has been developed by using hydrosilanes as reducing agents. The optimized conditions were successfully applied to the reactions of quinolines, quinoxalines, and quinoline N-oxides. They were also effective for the reduction of quinolines bearing amino or hydroxy groups, where H2 was evolved through dehydrogenative silylation of the amine or hydroxy moieties. Preliminary mechanistic studies revealed that the initial step in the catalytic cycle involves 1,4-addition of the hydrosilane to the quinoline to give a 1,4-dihydroquinoline; this is followed by (transfer) hydrogenation to deliver the tetrahydroquinoline as the final product.

Supporting Information

 
  • References and Notes

    • 1a Stout DM. Meyers AI. Chem. Rev. 1982; 82: 223
    • 1b Forrest TP. Dauphinee DA. Deraniyagala SA. Can. J. Chem. 1985; 63: 412
    • 1c Keay JG. Adv. Heterocycl. Chem. 1986; 39: 1
    • 1d Keay JG. In Comprehensive Organic Synthesis . Vol. 8 Trost BM. Fleming I. Pergamon; Oxford; 1991: 579
    • 1e Gribble GW. Chem. Soc. Rev. 1998; 27: 395
    • 1f Pitts MR. Harrison JR. Moody CJ. J. Chem. Soc., Perkin Trans. 1 2001; 955
    • 1g Hollmann F. Arends IW. C. E. Buehler K. ChemCatChem 2010; 2: 762
    • 1h Bull JA. Mousseau JJ. Pelletier G. Charette AB. Chem. Rev. 2012; 112: 2642
    • 1i Wan J.-P. Liu Y. RSC Adv. 2012; 2: 9763
    • 1j Park S. Chang S. Angew. Chem. Int. Ed. 2017; in press DOI: 10.1002/anie.201612140
    • 2a Krygowski TM. Cryaňski MK. Chem. Rev. 2001; 101: 1385
    • 2b Balaban AT. Oniciu DC. Katritzky AR. Chem. Rev. 2004; 104: 2777
    • 2c Pape AR. Kaliappan KP. Kündig EP. Chem. Rev. 2000; 100: 2917
    • 3a Katritzky AR. Rachwal S. Rachwal B. Tetrahedron 1996; 52: 15031
    • 3b Sridharan V. Suryavanshi PA. Menéndez JC. Chem. Rev. 2010; 111: 7157
    • 4a Wu J. Wang C. Tang W. Pettman A. Xiao J. Chem. Eur. J. 2012; 18: 9525
    • 4b Tang W.-J. Tan J. Xu L.-J. Lam K.-H. Fan Q.-H. Chan AS. C. Adv. Synth. Catal. 2010; 352: 1055
    • 4c Wu J. Tang W. Pettman A. Xiao J. Adv. Synth. Catal. 2013; 355: 35
    • 4d Ye Z.-S. Chen M.-W. Chen Q.-A. Shi L. Duan Y. Zhou Y.-G. Angew. Chem. Int. Ed. 2012; 51: 10181
    • 4e Dobereiner GE. Nova A. Schley ND. Hazari N. Miller SJ. Eisenstein O. Crabtree RH. J. Am. Chem. Soc. 2011; 133: 7547
    • 4f Adam R. Cabrero-Antonino JR. Spannenberg A. Junge K. Jackstell R. Beller M. Angew. Chem. Int. Ed. 2017; 56: 3216
    • 4g Chen F. Surkus A.-E. He L. Pohl M.-M. Radnik J., Topf C., Junge K., Beller M. 2015; 137: 11718
    • 5a Hounjet LJ. Stephan DW. Org. Process Res. Dev. 2014; 18: 385
    • 5b Stephan DW. Greenberg S. Graham TW. Chase P. Hastie JJ. Geier SJ. Farrell JM. Brown CC. Heiden ZM. Welch GC. Ulrich M. Inorg. Chem. 2011; 50: 12338
    • 5c Paradies J. Synlett 2013; 24: 777
    • 5d Erős G. Nagy K. Mehdi H. Pápai I. Nagy P. Király P. Tárkányi G. Soós T. Chem. Eur. J. 2012; 18: 574
    • 5e Maier AF. G. Tussing S. Schneider T. Flörke U. Qu Z.-W. Grimme S. Paradies J. Angew. Chem. Int. Ed. 2016; 55: 12219
    • 5f Eisenberger P. Bestvater BP. Keske EC. Crudden CM. Angew. Chem. Int. Ed. 2015; 54: 2467
    • 6a Geier SJ. Chase PA. Stephan DW. Chem. Commun. (Cambridge) 2010; 46: 4884
    • 6b Farrell JM. Heiden ZM. Stephan DW. Organometallics 2011; 30: 4497
    • 7a Tan M. Zhang Y. Tetrahedron Lett. 2009; 50: 4912
    • 7b Greb L. Tamke S. Paradies J. Chem. Commun. (Cambridge) 2014; 50: 2318
    • 7c Liu Z.-Y. Wen Z.-H. Wang X.-C. Angew. Chem. Int. Ed. 2017; 56: 5817
    • 8a Gandhamsetty N. Joung S. Park S.-W. Park S. Chang S. J. Am. Chem. Soc. 2014; 136: 16780
    • 8b Gandhamsetty N. Park S. Chang S. J. Am. Chem. Soc. 2015; 137: 15176
  • 9 Voutchkova A. Gnanamgari MD. Jakobsche CE. Butler C. Miller SJ. Parr J. Crabtree RH. J. Organomet. Chem. 2008; 693: 1815
  • 10 Manas MG. Sharninghausen LS. Balcells D. Crabtree RH. New J. Chem. 2014; 38: 1694
  • 11 2-Methyl-1,2,3,4-tetrahydroquinoline (2a);14 Typical Procedure In a 1.5 mL reaction vial, B(C6F5)3 (0.025 mmol, 5.0 mol%) was dissolved in CHCl3 (0.60 mL), and Et2SiH2 (1.75 mmol, 3.5 equiv) was added. To this catalyst solution was subsequently added 2-methylquinoline (1a; 0.50 mmol, 1.0 equiv). The mixture was stirred at 65 °C for 6 h, allowed to cool to r.t., and concentrated under reduced pressure to give a crude product. This was treated sequentially with 0.25 N ethereal HCl solution (7 mL) and sat. methanolic Na2CO3·H2O (1.0 mL) to neutralize the crude solution. Finally, the neutralized mixture was purified by column chromatography [silica gel, EtOAc–hexane (1:9)] to give a light-yellow liquid; yield: 56 mg (76%, 0.38 mmol). 1H NMR (600 MHz, CDCl3): δ = 7.03– 6.91 (m, 2 H), 6.62 (t, J = 7.4 Hz, 1 H), 6.48 (d, J = 8.3 Hz, 1 H), 3.68 (s, 1 H), 3.46 – 3.34 (m, 1 H), 2.91–2.79 (m, 1 H), 2.79–2.67 (m, 1 H), 2.00–1.84 (m, 1 H), 1.67–1.51 (m, 1 H), 1.22 (d, J = 6.3 Hz, 3 H). 13C NMR (150 MHz, CDCl3): δ = 144.7, 129.2, 126.6, 121.1, 116.9, 113.9, 47.1, 30.1, 26.6, 22.6.
  • 12 Ma Y. Wang B. Zhang L. Hou Z. J. Am. Chem. Soc. 2016; 138: 3663
  • 13 Although we observed hydrogen evolution through dehydrogenative silylation at the C-6 position during the catalytic turnover, homocoupling of the hydrosilane15 giving rise to a disilane and H2 should also be considered as another minor pathway under borane catalysis.
  • 14 Guo Q.-S. Du D.-M. Xu J. Angew. Chem. Int. Ed. 2008; 47: 759
  • 15 Brown-Wensley KA. Organometallics 1987; 6: 1590