A General Protocol for C−H Difluoromethylation of Carbon Acids with TMSCF
<sub>2</sub>
Br
作者:Qiqiang Xie、Ziyue Zhu、Lingchun Li、Chuanfa Ni、Jinbo Hu
DOI:10.1002/anie.201900763
日期:2019.5.6
efficient method for the selectiveC‐difluoromethylation of carbon acids with the reagent TMSCF2Br has been developed. A variety of structurally diverse sp3‐ and sp‐hybridized carbon nucleophiles, including esters, amides, fluorenes, terminal alkynes, β‐ketoesters, malonates, and other activated C−H nucleophiles, could be efficiently and selectively transformed into the corresponding C‐difluoromethylated
new and simple one-pot procedure for the palladium-catalyzedintermolecular α-arylation of esters is described. A number of esters can be functionalized with a wide range of aryl bromides using Pd(OAc)2 or Pd2(dba)3 and bulky electron-rich o-biphenyl phosphines 1−3. Under the reaction conditions, using LiHMDS as base, α-arylation proceeds at roomtemperature or at 80 °C with very good yields and high
facile access to various opticallyactive α-arylpropionic acids including several nonsteroidal anti-inflammatory drugs (NSAIDs) of commercial importance. (R,R)-QuinoxP* is specifically able to induce chirality when compared to analogous P-chiral ligands that give racemic products, highlighting the critical importance of transmetalation in the present asymmetric cross-coupling system.