Synthesis 2002(8): 1110-1114
DOI: 10.1055/s-2002-31970
© Georg Thieme Verlag Stuttgart · New York

A Practical Indium Tribromide Catalysed Addition of Indoles to Nitroalkenes in Aqueous Media

Marco Bandini*, Paolo Melchiorre, Alfonso Melloni, Achille Umani-Ronchi*
Dipartimento di Chimica ‘G. Ciamician’, Università di Bologna, Via Selmi 2, 40126 Bologna, Italy
Fax: +39(51)2099456; e-Mail:,;
Further Information

Publication History

Received 27 March 2002
Publication Date:
03 June 2002 (online)


The 1,4-conjugate addition of indoles to nitroalkenes was efficiently carried out in aqueous media using a catalytic amount of indium tribromide (5 mol%). The reusability of the indium tribromide was tested by performing consecutive cycles with the same catalyst.


  • 1a For recent reviews see: Leonard J. Contemp. Org. Synth.  1994,  1:  387 
  • 1b Rossiter BE. Swingle NM. Chem. Rev.  1992,  92:  771 
  • 2 Fînaru A. Berthault A. Besson T. Guillaumet G. Berteina-Raboin S. Tetrahedron Lett.  2002,  43:  787 
  • 3a Zhu HJ. Zhao BT. Zuo GY. Pittman CU. Dai WM. Hao XJ. Tetrahedron: Asymmetry  2001,  12:  2613 
  • 3b Paulvannan K. Hale R. Mesis R. Chen T. Tetrahedron Lett.  2002,  43:  203 
  • 4a Yevich JP. Yocca FD. Curr. Med. Chem.  1997,  4:  295 
  • 4b Jand KS. Barrett V. Brockwell M. Cambridge D. Farrant DR. Foster C. Giles H. Glen RC. Hill AP. Hobbs H. Honey A. Martin GR. Salmon J. Smith D. Woollard P. Selwood DL. J. Med. Chem.  2001,  44:  681 
  • 5a Noland WE. Hartman PJ. J. Chem. Soc.  1954,  76:  3227 
  • 5b Noland WE. Christensen GM. Sauer GL. Dutton GGS. J. Chem. Soc.  1955,  77:  456 
  • 6a Chakrabarty M. Basak R. Ghosh N. Tetrahedron Lett.  2001,  41:  3913 
  • 6b Komoto I. Kobayashi S. Org. Lett.  2002,  4:  in press 
  • 7 Bandini M. Cozzi PG. Giacomini M. Melchiorre P. Selva S. Umani-Ronchi A. J. Org. Chem.  2002,  67: in press
  • 8 Recently, Yadav et. al. reported that InCl3 (10 mol%) was also able to promote the conjugate addition of indole 5b to 6a in 78% yield using CH2Cl2 as the solvent. However, only one example of conjugate addition to nitroalkenes was described, see: Yadav JS. Abraham S. Reddy BVS. Sabitha G. Synthesis  2001,  2165.  Under our conditions, InCl3 was found less effective in comparison to InBr3 in the addition of 5a to 6a, 82% yield

Other common Lewis acids were found to be less effective in term of chemical yields and reaction times (i.e. AlCl3, 68% yield, 24 h).