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
Silver-Catalyzed Formal Inverse Electron-Demand Diels–Alder Reaction of 1,2-Diazines and Siloxy Alkynes
作者:Yunus E. Türkmen、Timothy J. Montavon、Sergey A. Kozmin、Viresh H. Rawal
DOI:10.1021/ja302537j
日期:2012.6.6
A highly effective silver-catalyzed formal inverse electron-demand Diels-Alder reaction of 1,2-diazines and siloxyalkynes has been developed. The reactions provide ready access to a wide range of siloxy naphthalenes and anthracenes, which are formed in good to high yields, under mild reaction conditions, using low catalyst loadings.
A [3+2] Cyclization of Siloxyalkynes and Isocyanides for the Synthesis of Oxazoles
作者:An Wu、Jianwei Sun
DOI:10.1055/s-0037-1610402
日期:2019.3
A mild and efficient [3+2] cyclization of siloxyalkynes for the synthesis of aromatic heterocycles is developed. It is a new addition to the cyclization reactions of these versatile species. In the presence of TBAF as promoter, siloxyalkynes react with electron-withdrawing isocyanides to form a range of oxazole products. In this reaction, siloxyalkynes contribute the C–O unit for the cyclization, which
Benzannulation of isobenzopyryliums with electron-rich alkynes: a modular access to β-functionalized naphthalenes
作者:An Wu、Hui Qian、Wanxiang Zhao、Jianwei Sun
DOI:10.1039/d0sc02502j
日期:——
A substituent-controlled divergent benzannulation provides rapid access to various β-functionalized naphthalenes from electron-rich alkynes.
一个取代基控制的分歧苯环化合物合成方法,能够快速从富电子炔烃中获得各种β-官能化的萘化合物。
Synthesis of Eight‐Membered Lactams through Formal [6+2] Cyclization of Siloxy Alkynes and Vinylazetidines
作者:An Wu、Qiang Feng、Herman H. Y. Sung、Ian D. Williams、Jianwei Sun
DOI:10.1002/anie.201902866
日期:2019.5.13
lactams through formal [6+2] cyclization of siloxyalkynes and vinylazetidines has been developed. Evidence from a chirality transfer experiment suggests that the reaction proceeds via a [3,3]‐sigmatropic rearrangement from a ketene intermediate. This insight led to the development of alternative conditions and use of acyl chlorides as ketene precursors for the [6+2] reaction with vinylazetidines.