A greener approach for the synthesis of 3-arylmethyl/diarylmethyl indoles has been achieved via a PMA-SiO2-mediated three-component reaction (the aza-Friedel-Crafts reaction) involving indoles, aldehydes, and N,N-disubstituted anilines in PEG-400. A variety of indole derivatives were prepared by using this operationally simple and straightforward methodology in acceptable yields.
Fe3O4-OSO3H was identified as an efficient reusable catalyst for the facile synthesis of diarylmethyl indole derivatives under neat condition by C-C bond forming reaction. Fe3O4-OSO3H catalysis was further extended to C-N bond forming reactions and for the synthesis of spermicidal 3,3'-di(indolyl)oxindole derivative. All the products were obtained in good to excellent yields. (C) 2015 Elsevier Ltd. All rights reserved.
ZnCl2 promoted efficient, one-pot synthesis of 3-arylmethyl and diarylmethyl indoles
mediated convenient, one-pot synthesis of 3-arylmethyl and diarylmethyl indoles was accomplished in good yields. Under reaction condition, in situ formation of kinetically stable bis(indolyl)methane product was identified. Its subsequent conversion to the thermodynamically stable 3-diarylmethyl indole at elevated temperature and pressure was confirmed by carrying out pressure tube reaction with bis(indolyl)methane