Thiocyanatomercuration des acetyleniques. Synthese de derives β-(iso)thiocyanatoalcenyl mercuriques, d'α-halo β-thiocyanato alcenes et de thiocyanato-1 alcynes-1

Abstract In the presence of (SCN) − mercuric chloride HgCl 2 adds to acetylenic compounds R 1 CCR 2 affording in most cases α-chloromercuri-β-thiocyanatoalkenes R 1 C(SCN)C(R 2 )HgCl and if R 1 = R 2 = Et or n-Bu isothiocyanates R 1 C(NCS)C(R 2 )HgCl. The action of halogens or thio compounds affords α-halo-β-thiocyanatoalkenes. Most of the reported reactions are regio- and stereo-specific, in particular both RC(SCN)CHBr and RCBrCHSCN may be regiospecifically obtained from 1-alkynes RCCH. The synthesis of 1-thiocyanato-1-alkynes is also reported.