catalytic coupling reaction of propargyl halides with organotitanium reagents is reported. The reaction of propargyl bromide with organo-titanium reagents mediated by NiCl2 (2 mol%) and PCy3 (4 mol%) in CH2Cl2 afforded coupling product allenes in good to excellent yields (up to 95%) at room temperature. However, NiCl2(PPh3)2 was the best catalyst for substituted propargyl halides to yield allenes or
Synthesis of Chiral α-CF<sub>3</sub>-Substituted Benzhydryls via Cross-Coupling Reaction of Aryltitanates
作者:Andrii Varenikov、Evgeny Shapiro、Mark Gandelman
DOI:10.1021/acs.orglett.0c03673
日期:2020.12.4
We describe a highly efficient approach toward α-CF3-substituted benzhydryls thanks to the employment of organotitanium(IV) based nucleophiles. The use of commercially available anesthetic halothane as a cheap fluorinated building block in a sequential one-pot nickel-catalyzed enantioselective cross-coupling reaction of aryl titanates allowed for the synthesis of chiral α-CF3-substituted benzhydryls
Organotitanium Nucleophiles in Asymmetric Cross-Coupling Reaction: Stereoconvergent Synthesis of Chiral α-CF<sub>3</sub> Thioethers
作者:Andrii Varenikov、Mark Gandelman
DOI:10.1021/jacs.9b05671
日期:2019.7.17
Ni-catalyzed cross-couplingreactions have become a very attractive tool for the stereoselective construction of valuable organic chiral materials. While various nucleophiles are used in such transformation, organotitanium (IV) has not been used before. Herein we demonstrate, for the first time, that organotitanium species can serve as efficient coupling partners in asymmetric cross-couplings, which have