A metal free chlorothiolation strategy for synthesis of vinyl sulfides from internal alkynoates

Recyclable Gold Catalyst for the Stereoselective Thioallylation of Alkynes

The heterogeneous gold(I)-catalyzed stereoselective thioallylation of electron-deficient alkynes with allyl sulfides has been achieved by using an MCM-41-immobilized sterically demanding NHC-gold(I) complex [MCM-41-IPrAuNTf₂] as the catalyst under mild conditions, delivering a wide variety of stereodefined tri- and tetrasubstituted functionalized vinyl sulfides in good to excellent yields. The new heterogeneous MCM-41-IPrAuNTf₂ catalyst exhibits an activity comparable to a homogeneous IPrAuNTf₂ complex and can be recovered via a simple filtration process and reused for at least seven consecutive cycles without any apparent loss of its catalytic activity and selectivity.