Bisalkynyl tosylates

The presence of catalytic amounts of cuprous triflate or silver(I) sulfonates exerts a remarkable influence on the activation energy and regiochemistry of alkynyl(phenyl)-iodonium tosylate and mesylate decompositions5,6. Such reactions proceed in acetonitrile at room temperature and afford moderate yields of alkynyl tosylates and mesylates (equations 82 and 83)5,6. It is noteworthy, however, that the treatment of alkynyliodonium triflates (R = n-Bu, r-Bu) with cuprous triflate in acetonitrile does not afford alkynyl triflates6. Silver(I) catalysis has similarly been applied to the conversion of bis(alkynyliodo-nium) tosylates to bisalkynyl tosylates (equation 84)43. As might be expected, mono-tosylate esters are also produced in these reactions. 

Reaction of alkynyliodonium sulfonates, 9, in dry acetonitrile in the presence of catalytic amounts of AgOTs or CuOTf leads to the formation of alkynyl sulfonates, 70, in reasonable yields [Eq. (30)] [18], In a similar manner bis(alkynyliodonium) tosylates, 36, give modest yields of bisalkynyl tosylates, 71, accompanied by some monotosylates, 72 [Eq. (31)] [41]. 

---

See also in sourсe #XX -- [ ]

---