Direct Sulfide-Catalyzed Enantioselective Cyclopropanations of Electron-Deficient Dienes and Bromides
作者:Qing-Zhu Li、Xiang Zhang、Rong Zeng、Qing-Song Dai、Yue Liu、Xu-Dong Shen、Hai-Jun Leng、Kai-Chuan Yang、Jun-Long Li
DOI:10.1021/acs.orglett.8b01537
日期:2018.6.15
A catalytic highly regioselective, diastereoselective, and enantioselective cyclopropanation of electron-deficient dienes and bromides via direct sulfide organocatalysis is reported. A variety of vinylcyclopropanes featuring a quaternary chiral center were synthesized in up to 99% yield and up to 98:2 enantiomeric ratio (er). These products could be facilely transformed to various interesting molecules
Ring-expansion of 3-bromoalkyl-1,2-benzisothiazole 1,1-dioxides to (2H)-1,2-benzothiazin-4(3H)-one 1,1-dioxides
作者:Rudolph A. Abramovitch、Kundalika M. More、Ichiro Shinkai、Panayencheri C. Srinivasan
DOI:10.1039/c39760000771
日期:——
A simple three-step synthesis of (2H)-1,2-benzothiazin-4(3H)-one 1,1-dioxides from saccharin has been achieved by the base-mediated ring-expansion of 3-(α-bromoalkyl)-1,2-benzisothiazole 1,1-dioxides.
TRIFLUOROMETHANESULFONAMIDE DERIVATIVES, PROCESS FOR THEIR PREPARATION, AND HERBICIDES CONTAINING SAME
申请人:IDEMITSU KOSAN COMPANY LIMITED
公开号:EP0305529A1
公开(公告)日:1989-03-08
Trifiuoromethanesuifonamide derivatives represented by general formula (I), herbicides containing them as effective ingredients, and a process for their preparation. In formula (1),
X represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or a haloalkyl group having 1 to 4 carbon atoms, n represents 1, 2, or 3, A represents (II), (III), (IV), (V) or (VI),
and R1, R2, R3, each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. These compounds are prepared by reacting a corresponding amine derivative with trifluoromethanesulfonyl halide or trifluoromethanesulfonic acid anhydride or by oxidizing a thiochroman ring-containing trifluoromethanesulfonamide derivative depending upon the kind of group A in the above general formula. These trifluoromethanesulfonamide derivatives are useful as herbicides and enable the removal of weed without exhibiting any phytotoxicity upon field crops. The derivatives are also utilized as plant growth regulators.