3-Chlorophenylboronic acid-promoted, one-pot,
aza-Friedel–Crafts reaction of indoles
Santosh V. Goswami
Prashant B. Thorat
Mahesh V. Shukla
Sudhakar R. Bhusare
Received: 12 March 2013 / Accepted: 9 August 2013 / Published online: 21 August 2013
Ó Springer Science+Business Media Dordrecht 2013
Abstract 3-Chlorophenylboronic acid promotes efﬁcient synthesis of 3-substi-
tuted indole derivatives via aza-Friedel–Crafts reaction of indoles, aromatic alde-
hydes, and N,N-dimethylaniline at room temperature. The mild reaction conditions,
excellent yields, and easy experimental workup are striking features of this proce-
dure for synthesis of 3-substituted indoles.
Keywords: Aza-Friedel–Crafts reaction Á 3-Chlorophenylboronic
acid Á Indole Á Aromatic aldehyde Á N,N-Dimethylaniline
Indole derivatives occur widely in nature and many are physiologically active [1–3].
3-Substituted indoles, in particular, are important reagents in the synthesis of a
variety of biologically active molecules. 3-Substituted indoles are regarded as
pharmacophores in drug discovery  and are found in variety of natural products,
for example 5-HT1B/1D receptor agonists used for treatment of migraine,
aromatase inhibitors used to treat breast cancer [5, 6], HIV-1 integrase inhibitors
[7, 8], gramine, and sumatriptan. Indole derivatives have a variety of biological
activity, for example antibacterial, antioxidative, and insecticidal , and some
indole derivatives have been used as antibiotics in pharmaceuticals .
There is a continuing need for new procedures for synthesis of 3-substituted
indoles. A variety of methods have been developed for the synthesis of 3-substituted
indoles [11–17]. Friedel–Crafts reactions are among the most important processes
used to introduce new carbon–carbon bonds into aromatic compounds .
Organoboron compounds have been successfully used as effective Lewis acid
S. V. Goswami Á P. B. Thorat Á M. V. Shukla Á S. R. Bhusare (&)
Department of Chemistry, Dnyanopasak College, Parbhani 431 401, Maharashtra, India
Res Chem Intermed (2015) 41:2583–2589