Diastereoselective synthesis of CF<sub>3</sub>-dihydrobenzofurans by [4+1] annulation of <i>in situ</i>-generated CF<sub>3</sub>-<i>o</i>-quinone methides and sulfur ylides
作者:Babli K. Jha、Jaggaraju Prudhviraj、Prathama S. Mainkar、Nagender Punna、Srivari Chandrasekhar
DOI:10.1039/d0ra08289a
日期:——
An efficient and highly diastereoselective synthesis of CF3-dihydrobenzofurans by the reaction of in situ-generated CF3-oQMs in the presence of a base with sulphur ylides is put forward. The generality of the present developed method was well studied with diverse substrates to access the corresponding products in excellent yields. The highlyreactive CF3-oQM has been utilized first time for the annulation
提出了一种在碱存在下原位生成的CF 3 - o QMs与硫叶立德反应高效、高度非对映选择性合成CF 3 -二氢苯并呋喃的方法。本开发方法的通用性已通过多种底物得到很好的研究,以优异的产量获得相应的产品。高反应性CF 3 - o QM 首次用于环化反应。
Nucleophilic replacement of p-(1-chloro-2,2,2-trifluoroethyl)phenols: novel synthesis of β-trifluoromethyl-tyrosine
作者:Yuefa Gong、Katsuya Kato
DOI:10.1016/s0022-1139(03)00004-6
日期:2003.6
Three para-(1-chloro-2,2,2-trifluoroethyl)phenols 2a–c were prepared by selective α-chlorination of the corresponding alcohols 1a–c. Substitution of 2a by active methylene compound 4 proceeds smoothly in the presence of an appropriate base at room temperature, giving substituted products 5–9 in good yields. On the basis of this finding, both the important β-trifluoromethyl-tyrosine 15 and its derivatives
Facile Synthesis of o- and p-(1-Trifluoromethyl)-alkylated Phenols via Generation and Reaction of Quinone Methides
作者:Yuefa Gong、Katsuya Kato
DOI:10.1055/s-2002-20458
日期:——
Several ortho- and para-(1-chloro-2,2,2-trifluoroethyl)phenols were prepared from the corresponding alcohols and thionyl chloride in the presence of pyridine. They reacted smoothly with sodium borohydride and Grignard reagents under mild conditions, forming 2,2,2-trifluoroethyl- or 1-trifluoromethylalkylphenols in high yields.