Addition de l'acide thiocyanique aux acetyleniques a l'aide de Hg(II)-I : Addition du groupement (SCN)- en presence d'un acide fort

Resume Mercury(II) thiocyanate Hg(SCN) 2 catalyses thiocyanic acid HSCN addition to unactivated acetylenic compounds R 1 -CC-R 2 . Bonding of the SCN moiety to carbon occurs through sulphur or nitrogen depending upon the influence of R 1 and R 2 ; vinyl thiocyanates NCS-C(R 1 )CH 2 are obtained specifically from terminal acetylenic compounds but some symmetrically disubstituted alkynes may afford vinyl isothiocyanates SCN-C(R 1 )CH–R 2 (R 1 R 2 Et, n-Bu). A simple preparation of tet- raphenylphosphonium hydrogen dithiocyanate Ph 4 P+[H(SCN) 2 ] - is reported.