Synthesis and reactivity of dicobalt stabilised but-2-yne-1,4-dicarbenium ions

Abstract

Treatment of [Co₂(µ-HOCH₂CCCH₂OH)(CO)₆] in Me₂S with HBF₄·OEt₂ affords the stable salt [Co₂(µ-Me₂SCH₂CCCH₂SMe₂)(CO)₆][BF₄]₂ which reacts with secondary amines to afford [Co₂(µ-R₂NCH₂CCCH₂NR₂)(CO)₆](R = Et or Ph), while treatment of [Co₂(µ-HOCH₂CCCH₂OH)(µ-dppm)₂(CO)₂][dppm = bis(diphenylphosphino)methane] with HBF₄·OEt₂ affords a stable dicarbenium complex [Co₂(µ-H₂CCCCH₂)(µ-dppm)₂(CO)₂][BF₄]₂ which forms adducts with pyridine and triphenylphosphine.