NaBH4/[bmim]BF4: a new reducing system to access vinyl selenides and tellurides

A general and simple method for the synthesis of vinyl selenides and tellurides starting from terminal alkynes and diorganyl chalcogenides using NaBH4 and [bmim]BF4 as a recyclable solvent was developed. This efficient and improved method furnishes the corresponding vinyl chalcogenides preferentially with Z configuration. We also observed that when the same protocol was applied to phenyl acetylene, (E)-bis-phenylchalcogeno styrenes were obtained in good yields and high selectivity. The ionic liquid was reused up three times without lost of efficiency.