G. A. Meshram and V. D. Patil, “Simple and Efficient Method for Synthesis of Bis(indolyl) Methanes with Cu(BF4)₂·SiO₂ Under Mild Conditions,” Synthetic Communications, Vol. 40, No. 1, 2010, pp. 29-38. doi:10.1080/00397910902916064

has been cited by the following article:

• TITLE: New Greener Alternative for Biocondensation of Aldehydes and Indoles Using Lemon Juice: Formation of Bis-, Tris-, and Tetraindoles

  AUTHORS: Rammohan Pal

  KEYWORDS: Citrus limon Juice; Biocondensation; Aldehydes; Indoles; Aqueous Ethanol; Sonication; Bis-; Tris-; Tetraindoles

  JOURNAL NAME: International Journal of Organic Chemistry, Vol.3 No.2, June 14, 2013

  ABSTRACT: This work presents a new greener alternative for biocondensation of aldehydes and indoles for the synthesis of bis- and tris(indolyl)methanes catalyzed by lemon juice (Citrus limon) in good yields under ultrasound irradiation in aqueous ethanol. Various substituted aldehydes with indoles under this reaction condition are elucidated. Also, tetraindolyl compounds were prepared using terephthaldialdehyde by following the same protocol. This method is an environmentally benign, efficient reaction, which requires shorter reaction time and simple experimental and work-up procedures.