Copper-Catalyzed Carboxylation of C–F Bonds with CO2
摘要:
An effective Cu-catalyzed selective formal carboxylation of C-F bonds with an atmospheric pressure of CO2 is reported. A variety of gem-difluoroalkenes, gem-difluorodienes, and alpha-trifluoro-methyl alkenes show high reactivity and selectivity for this ipso monocarboxylation. Under mild conditions, diverse important alpha-fluoroacrylic acids and alpha,alpha-difluorocarboxylates are obtained in good-to-high yields. Moreover, this operationally simple protocol features good functional group tolerance, is readily scalable, and the resulting products are readily converted into bioactive alpha-fluorinated carbonyl compounds, indicating potential application in biochemistry and drug discovery. Mechanistic studies reveal that fluorinated boronate esters might be vital intermediates in this transformation.
first time. The reaction is stereospecific and provides fair to quantitative yields of fluoroalkenes. The Mizoroki–Heck reaction starting from more hindered and usually reluctant trisubstituted acrylate, to access tetrasubstituted fluoroalkenes, is also reported. Finally, the use of a three-step synthesis sequence, including Mizoroki–Heck reaction, allows the synthesis of fluorinated analogues of therapeutic
In this manuscript, a simple and efficient sulfa-Michael addition reaction of aryl thiols to trisubstituted α-fluoro-α,β-unsaturated esters both in racemic and, for the first time, in enantioselective version is reported. The commercially available dimer of cinchona derivatives (DHQ)2PYR was used as a catalyst. This strategy showed a great tolerance for various substrates and substituents, providing