Annulation of β-naphthols and 4-hydroxycoumarins with vinylsulfonium salts: synthesis of dihydrofuran derivatives
作者:Zi-cong Chen、Lang Tong、Zhi-bo Du、Zhi-feng Mao、Xue-jing Zhang、Yong Zou、Ming Yan
DOI:10.1039/c8ob00293b
日期:——
A new synthetic approach to dihydrofuranderivatives via the annulation reaction of β-naphthols and 4-hydroxycoumarins with vinylsulfonium salts has been developed. A variety of dihydrofuranderivatives were prepared in moderate to good yields under mild conditions. The products could be readily transformed to the corresponding furans via the dehydrogenation with DDQ.
Highly Selective Activation of Vinyl C-S Bonds Over Aryl C-S Bonds in the Pd-Catalyzed Coupling of (E)-(β-Trifluoromethyl)vinyldiphenylsulfonium Salts: Preparation of Trifluoromethylated Alkenes and Dienes
作者:Hao Lin、Xicheng Dong、Yuxue Li、Qilong Shen、Long Lu
DOI:10.1002/ejoc.201200758
日期:2012.9
We describe the Suzuki coupling reaction of (E)-(beta-trifluoromethyl)vinyldiphenylsulfoniumsalts with arylboronic acid. The highly efficient and selective reaction provides a useful and mild method for the synthesis of trifluoromethylatedalkenes and dienes. Subsequent DFT studies showed that the oxidative addition transition state of the vinyl CS bond is much more favorable (11.7 kcal?mol1) than
yl)vinylsulfonium triflate, readily prepared from 2-bromo-3,3,3-trifluoroprop-1-ene in two steps, undergoes double alkylation with active methylene compounds in dimethyl sulfoxide or ethyl acetate, in an open vessel at room temperature, to provide the corresponding trifluoromethylated cyclopropane derivatives in excellent yields. The cyclopropane, ethyl 1-cyano-2-(trifluoromethyl)cyclopropanecarboxylate
Diastereoselective Synthesis of CF<sub>3</sub>-Substituted, Epoxide-Fused Heterocycles with β-(Trifluoromethyl)vinylsulfonium Salts
作者:Sven P. Fritz、Thomas H. West、Eoghan M. McGarrigle、Varinder K. Aggarwal
DOI:10.1021/ol303200n
日期:2012.12.21
CF3-substituted vinyl diphenylsulfonium triflate is an effective annulation reagent for the formation of alpha-CF3 substituted, epoxide-fused heterocycles (pyrrolidines, piperidines, and tetrahydrofurans). This simple method affords a variety of valuable heterocyclic building blocks in a highly diastereoselective manner (dr>20:1).