Generation of 1,2-oxathiolium ions from (arysulfonyl)- and (arylsulfinyl)allenes in Brønsted acids. NMR and DFT study of these cations and their reactions
作者:Stanislav V Lozovskiy、Alexander Yu Ivanov、Olesya V Khoroshilova、Aleksander V Vasilyev
DOI:10.3762/bjoc.14.268
日期:——
In strong Brønsted acids (CF3SO3H, FSO3H, D2SO4), (arysulfonyl)allenes (ArSO2-CR1=C=CR2R3) and (arylsulfinyl)allenes (ArSO-CR1=C=CR2R3) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl, leads to their deprotonation with a stereoselective formation
在强布朗斯台德酸(CF3SO3H,FSO3H,D2SO4)中,(芳磺酰基)烯(ArSO2-CR1 = C = CR2R3)和(芳亚磺酰基)烯(ArSO-CR1 = C = CR2R3)环化成相应的稳定的1,2-氧杂硫鎓离子,通过NMR和DFT计算进行了研究。用低亲核介质(HCl水溶液)淬灭这些阳离子的溶液会导致它们的去质子化,并形成立体选择性的(芳磺酰基)丁二烯(例如,ArSO2-CR1 = CC(Me)= CH2,对于R2 = R3 = Me,收率的87-98%)。TfOH(0.1当量)-HFIP(六氟丙烷-2-醇)体系中的(芳磺酰基)丙二烯反应后水解生成烯丙醇(ArSO2-CR1 = CH-C(OH)R2R3,收率78-99% )。在(1当量)TfOH(1当量)存在下,(芳磺酰基)丙二烯溶液的回流导致环化成硫代色素1,1-二氧化物产量高。在TfOH或AlX 3(X = Cl,Br)的作