Improved, efficient, grams scale synthesis of α-(difluoromethyl)styrene (DFMST) based on nucleophilic difluoromethylation process using difluoromethylphenyl sulfone, is presented. Difluoromethylating agent (PhSO2CF2H) was obtained in two-step synthetic sequence with 69% overall yield. Three-step DFMST synthetic route was easily implemented for the preparation of gram quantities of the monomer, allowing
2-trifluoromethyl-1-alkenes and alkynes with the aid of Et3SiH provides 1,1-difluoro-1,4-dienes under mild reaction conditions. This reaction involves selective allylic C(sp3)–F bond activation via β-fluorine elimination from nickelacyclopentenes.
Ir-catalyzed enantioselective addition of an N-methyl C–H bond of 2-(methylamino)pyridine derivatives to α-trifluoromethylstyrenes proceeded via C–Hactivation to give chiral γ-branched amine derivatives having a trifluoromethyl-substituted stereocenter. It was found that a bulky and electron-withdrawing group at the 3-position of 2-(methylamino)pyridines was necessary for the present C–H addition reaction
Syntheses of Mono-, Di-, and Trifluorinated Styrenic Monomers
作者:Véronique Gouverneur、Justyna Walkowiak、Teresa del Campo、Bruno Ameduri
DOI:10.1055/s-0029-1218785
日期:2010.6
Concise syntheses of gram quantities of three fluorinated α-methylstyrenic monomers suitable for polymerisation studies are disclosed, all based on the use of reasonably priced commercially available starting materials and reagents. fluorination - nucleophilic fluoroalkylation - palladium catalysis - monomer synthesis - functional fluoropolymers
Catalytic Enantioselective Synthesis of Highly Functionalized Difluoromethylated Cyclopropanes
作者:Maxence Bos、Wei-Sheng Huang、Thomas Poisson、Xavier Pannecoucke、André B. Charette、Philippe Jubault
DOI:10.1002/anie.201707375
日期:2017.10.16
The first catalyticasymmetricsynthesis of highly functionalized difluoromethylated cyclopropanes is described. The method, based on a rhodium‐catalyzed cyclopropanation of difluoromethylated olefins, gives access to a broad range of cyclopropanes bearing ester, ketone, or nitro functional groups. By using Rh2((S)‐BTPCP)4 as a catalyst, the corresponding products were obtained in high yields and high