Brønsted acid-promoted cyclizations of siloxy alkynes with unactivated arenes, alkenes, and alkynes
作者:Liming Zhang、Jianwei Sun、Sergey A. Kozmin
DOI:10.1016/j.tet.2006.06.037
日期:2006.12
found that trifluoromethane sulfonimide (HNTf2) proved to be a superior promoter of these reactions compared to a range of other Brønsted acids. This finding could be attributed to a high acidity of HNTf2 in aprotic organic solvents combined with a low nucleophilicity of the NTf2− anion. Depending on the nature of the nucleophile, the carbocyclizations proceeded either via 6-endo-dig or 5-endo-dig manifolds