115134-69-5Relevant articles and documents
2-ISOTHIOCYANATOBENZYLTRIPHENYLPHOSPHONIUM BROMIDES - NEW TYPE OF FUNCTIONALIZED HETEROCUMULENES SUITABLE FOR SYNTHESIS OF INDOLE DERIVATIVES
Gonda, Jozef,Kristian, Pavol,Imrich, Jan
, p. 2508 - 2520 (2007/10/02)
Reaction of 2-bromomethylphenyl isothiocyanates with triphenylphosphine afforded triphenyl-(2-isothiocyanatobenzyl)phosphonium salts.Their reaction with bases liberated the corresponding carbanions which on intramolecular addition to the N=C=S group gave substituted 3-triphenylphosphoniumindolyl-2-thiolates.These compounds did not react in the Wittig reaction but underwent electrophilic reactions on the sulfur atom or the indol nitrogen atom.According to a detailed analysis of 1H, 13C, 31P NMR and mass spectra, the indole derivatives exist predominantly in the betaine form.X-Ray diffraction analysis of the unsubstituted betaine, 3-triphenylphosphoniumindolyl-2-thiolate, agrees well with the spectral results.