The gold(I)-catalyzed reaction of bromoalkynes with allylsilanes gives 1,4-enynes in a formal cross-coupling reaction. Mechanistic studies revealed the involvement of gold(I) vinylidenes or vinylidenephenonium gold(I) cations depending on the substituent on the bromoalkyne. In the case of bromo arylalkynes, the vinylidenephenonium gold(I) cations lead to 1,4-enynes via a 1,2-aryl rear-rangement. The same reactivity has been observed in the presence of InBr3.
Gold- or Indium-Catalyzed Cross-Coupling of Bromoalkynes with Allylsilanes through a Concealed Rearrangement
ACS Catal. 2019, 9 (9), 7817-7822, DOI: 10.1021/acscatal.9b02314.