Detosylation of 3-amino-1-tosylindole-2-carbonitriles using DBU and thiophenol
摘要:
Attempted detosylation of the 3-amino-1-(p-tosylamino)indole-2-carbonitriles 4a-c using either K2CO3 in EtOH or DBU in PhH at reflux gives unexpectedly the 3-(N-p-tosylamino)indole-2-carbonitriles 5a-c, respectively in high yields. Nevertheless, treatment of 1-(p-tosylamino)indoles 4a-c with thiophenol and DBU in PhH at reflux gives the detosylated 3-aminoindole-2-carbonitriles 5a-c. Reaction mechanisms supporting the tosyl migration (4 -> 5) and the reductive detosylation (4 -> 2) are proposed. All new compounds are fully characterised. (C) 2010 Elsevier Ltd. All rights reserved.
Hoveyda–Grubbs’ catalyst is able to catalyze crossed [2 + 2 + 2] cyclotrimerizations of diynes with nitriles. Pyridines are obtained with excellent yields when using activated nitriles and low to moderate yields with nonactivated nitriles which are unreactive under previously described ruthenium catalyzed reaction conditions. Both terminal and internal alkynes give the reaction using this experimental