A high-efficient and stereo-specific approach for the preparation of biologically important （E）-2-styryl-tetra- hydrobenzo[d]thiazoles has been developed via TMSC1 promoted direct sp3 C-H alkenylation of 2-methyl-5,...A high-efficient and stereo-specific approach for the preparation of biologically important （E）-2-styryl-tetra- hydrobenzo[d]thiazoles has been developed via TMSC1 promoted direct sp3 C-H alkenylation of 2-methyl-5,6-di- hydrobenzo[d]thiazol-7（4H）-one under metal-free conditions. Seventeen target compounds were synthesized in ex- cellent yields of 82%--98% under the optimal conditions of 300 mol% TMSCI at 110℃ for 2 h, and their chemical structures were elucidated by IR, NMR, ESI-MS, elemental analyses and X-ray crystallography analysis. A plausible mechanism was also proposed, and this method provided a good functional group conversion for the sp3 C-H substrates.展开更多
Treatment of N-t-butylbenzenesulfonamide with an excess of BuLi, followed by the reaction with methyl 2-（4-methylphenyl）propanoate, gave the corresponding 2-carboxybenzenesulfonamide, which underwent a sequence of c...Treatment of N-t-butylbenzenesulfonamide with an excess of BuLi, followed by the reaction with methyl 2-（4-methylphenyl）propanoate, gave the corresponding 2-carboxybenzenesulfonamide, which underwent a sequence of consecutive N-deprotective cyclization process mediated by TMSCI-NaI-MeCN reagent to afford the N-sulfonylimine. Following the bromination and ring expansion, 3-methyl-3-（4-methylphenyl）-2H-benzo[e][1,2]thiazine-l,l,4-trione was obtained. Optical resolution of the racemic benzosultam using （-）-menthoxyacetyl chloride, furnished the optically p.ure （＋）- and （-）-3-methyl-3-（4-methylphenyl）-2H- benzo[e][1,2]thiazine-1,1,4-triones, which were fluorinated with FC103 to produce the corresponding chiral N-F agents.展开更多
A simple and convenient procedure for stercoselective synthesis of （Z）-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethyls...A simple and convenient procedure for stercoselective synthesis of （Z）-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCI system to form selemde anions, which then undergo SN2＇ substitution of Baylis-Hillman adducts to produce the （Z）-allyl selenides.展开更多
Cationic polymerizations of 1,3-pentadiene (PD) initiated by trimethylsilyl chloride (TMSCl) incombination with TiCl_4 were carried out in n-hexane at 30℃. The yield of polymer was greatly increased bythe addition of...Cationic polymerizations of 1,3-pentadiene (PD) initiated by trimethylsilyl chloride (TMSCl) incombination with TiCl_4 were carried out in n-hexane at 30℃. The yield of polymer was greatly increased bythe addition of TMSCl, indicating that the TMSCl/TiCl_4 combination is an efficient initiating system for PDcationic polymerization. However, the introduction of TMSCl gave rise to a drop in the molecular weight ofthe polymer. Kinetic results demonstrated that the polymerization initiated by TMSCl/TiCl_4 is 4.5 times fasterthan that induced by TiCl_4 alone. Various ethers were used to mediate the TMSCl/TiCl_4 initiating system.Adding diphenyl ether could increase both the yield and molecular weight of the polymer. Structural evidenceillustrates that the polymerization is indeed initiated by TiCl_4 in combination with HCl resulting fromhydrolysis by adventitious water.展开更多
基金The authors thank the finance supported by the National Natural Science Foundation of China （No. 21272136）, and Scientific Research Innovation Founda- tion of Graduate School of China Three Gorges Univer- sity.
文摘A high-efficient and stereo-specific approach for the preparation of biologically important （E）-2-styryl-tetra- hydrobenzo[d]thiazoles has been developed via TMSC1 promoted direct sp3 C-H alkenylation of 2-methyl-5,6-di- hydrobenzo[d]thiazol-7（4H）-one under metal-free conditions. Seventeen target compounds were synthesized in ex- cellent yields of 82%--98% under the optimal conditions of 300 mol% TMSCI at 110℃ for 2 h, and their chemical structures were elucidated by IR, NMR, ESI-MS, elemental analyses and X-ray crystallography analysis. A plausible mechanism was also proposed, and this method provided a good functional group conversion for the sp3 C-H substrates.
基金the Scientific Research Foundation for the Returned Oversea Chinese Scholars of Shandong University.
文摘Treatment of N-t-butylbenzenesulfonamide with an excess of BuLi, followed by the reaction with methyl 2-（4-methylphenyl）propanoate, gave the corresponding 2-carboxybenzenesulfonamide, which underwent a sequence of consecutive N-deprotective cyclization process mediated by TMSCI-NaI-MeCN reagent to afford the N-sulfonylimine. Following the bromination and ring expansion, 3-methyl-3-（4-methylphenyl）-2H-benzo[e][1,2]thiazine-l,l,4-trione was obtained. Optical resolution of the racemic benzosultam using （-）-menthoxyacetyl chloride, furnished the optically p.ure （＋）- and （-）-3-methyl-3-（4-methylphenyl）-2H- benzo[e][1,2]thiazine-1,1,4-triones, which were fluorinated with FC103 to produce the corresponding chiral N-F agents.
基金Project (No. 2004C21032) supported by the Key Technologies R &D Program of Zhejiang Province, China
文摘A simple and convenient procedure for stercoselective synthesis of （Z）-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCI system to form selemde anions, which then undergo SN2＇ substitution of Baylis-Hillman adducts to produce the （Z）-allyl selenides.
基金The National Natural Sciences Foundation of China is gratefully acknowledged for its financial support (grant No. 29504032)
文摘Cationic polymerizations of 1,3-pentadiene (PD) initiated by trimethylsilyl chloride (TMSCl) incombination with TiCl_4 were carried out in n-hexane at 30℃. The yield of polymer was greatly increased bythe addition of TMSCl, indicating that the TMSCl/TiCl_4 combination is an efficient initiating system for PDcationic polymerization. However, the introduction of TMSCl gave rise to a drop in the molecular weight ofthe polymer. Kinetic results demonstrated that the polymerization initiated by TMSCl/TiCl_4 is 4.5 times fasterthan that induced by TiCl_4 alone. Various ethers were used to mediate the TMSCl/TiCl_4 initiating system.Adding diphenyl ether could increase both the yield and molecular weight of the polymer. Structural evidenceillustrates that the polymerization is indeed initiated by TiCl_4 in combination with HCl resulting fromhydrolysis by adventitious water.
