ADDITION DE L'ACIDE THIOCYANIQUE AUX ACETYLENIQUES A L'AIDE DE Hg(II)-I. ADDITION DU GROUPEMENT SCN(1-) EN PRESENCE D'UN ACIDE FORT
Mercury(II) thiocyanate Hg(SCN)2 catalyses thiocyanic acid HSCN addition to unactivated acetylenic compounds R1-CC-R2.Bonding of the SCN moiety to carbon occurs through sulphur or nitrogen depending upon the influence of R1 and R2; vinyl thiocyanates NCS-C(R1)=CH2 are obtained specifically from terminal acetylenic compounds but some symmetrically disubstituted alkynes may afford vinyl isothiocyanates SCN-C(R1)=CH-R2 ( R1=R2=Et, n-Bu ).A simple preparation of tetraphenylphosphonium hydrogen dithiocyanate Ph4P(1+)*(1-) is reported.