highly carbon‐selective difluoromethylation of soft carbon nucleophiles including β‐ketoesters, malonates, oxindoles, benzofuranones and ketenesilylacetals with a difluoromethylated sulfonium ylide under mild conditions was described. Mechanistic studies suggest that these difluoromethylating reactions proceed via a difluorocarbene pathway.
[[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide: A Shelf-Stable, Electrophilic Reagent with a Convertible Group for the Synthesis of Diversified Fluoroalkylthiolated Compounds
作者:Feng Shen、Panpan Zhang、Long Lu、Qilong Shen
DOI:10.1021/acs.orglett.7b00010
日期:2017.3.3
A shelf-stable and easily convertible reagent for the preparation of diversified fluoroalkylthiolated compounds, [[(ethoxycarbonyl)difluoromethyl]thio]phthalimide, was developed. [[(Ethoxycarbonyl)difluoromethyl]thio]phthalimide is an efficient electrophilic fluoroallylthiolating reagent that reacted with electron-rich heteroarenes/arenes, β-ketoesters, oxindoles, benzofuranones, and thiols. More importantly
Highly Enantioselective Michael Addition Reactions of 3-Substituted Benzofuran-2(3H)-ones to Chalcones Catalyzed by a Chiral Alkyl-Substituted Thiourea
作者:Xin Li、Zhiguo Xi、Sanzhong Luo、Jin-Pei Cheng
DOI:10.1002/adsc.201000106
日期:——
A highlyenantioselectiveMichaeladdition of 3‐substituted benzofuran‐2(3H)‐ones to chalcones catalyzed by a chiralbifunctionalthiourea was developed. Several chiral 3,3′‐substituted benzofuran‐2(3H)‐ones derivatives, bearing adjacent quaternary‐tertiary stereocenters, were efficiently synthesized with excellent enantioselectivities.
Asymmetric Difluoromethylthiolation of Carbon Nucleophiles with Optically Pure Difluoromethylthiolating Reagents Derived from Camphorsultam
作者:He Zhang、Xiaolong Wan、Qilong Shen
DOI:10.1002/cjoc.201900298
日期:2019.10
The invention of a family of optically pure electrophilic difluoromethylthiolating reagents 9a–c based on the camphorsultam skeleton was described. These reagents reacted with a variety of soft carbonnucleophiles such as oxazolone, oxindole, benzolactone and β‐ketoester in good to excellent enantioselectivities.
Asymmetric Michael Addition Reactions between 3-Substituted Benzofuran-2(3H)-ones and 1,1-Bis(phenylsulfonyl)ethylene Catalyzed by Bifunctional Catalysts Containing Tertiary Amine and Thiourea Groups
Highly enantioselective catalytic conjugate additions of 3-substituted benzofuran-2(3H)-ones to 1,1-bis(phenylsulfonyl)ethylene in the presence of catalysts based on Cinchona alkaloids and containing tertiaryamine and thiourea groups have been developed. Good to excellent stereoselectivities (up to 99 % ee) could be achieved. An interesting effect of substituent positions on stereoselectivities was