57337-98-1Relevant academic research and scientific papers
Triflate/mesylate ratios and competing C-O and S-O bond cleavages in nucleophilic vinylic substitution
Schottland, Ettie Z.,Rappoport, Zvi
, p. 8536 - 8543 (2007/10/03)
In an attempt to develop the kOTf/kOMs ratio as a mechanistic tool for the "addition-elimination" route in nucleophilic vinylic substitution, several pairs of vinyl mesylates and triflates were prepared. Whereas reactions of ArC(LG)=C(CO2Et)2 (LG = OTf, OMs) with piperidine and morpholine in MeCN or THF gave the normal substitution product with kOTf/kOMs ratios of 4.3-10.6, the reaction of the mesylates, Ar = p-O2NC6H4, and of PhC(OMs)=C(Me)CN with MeS- gave a ketone via an S-O bond cleavage. A related mesityl-substituted tosylate also reacted with p-MeC6H4X- (X = O, S) via an S-O bond cleavage. Hence, kOTf/kOMs ratios cannot be used as a general mechanistic tool. Several reactivity ratios in vinylic substitution are briefly discussed.
