Synthesis of diverse β-quaternary ketones via palladium-catalyzed asymmetric conjugate addition of arylboronic acids to cyclic enones
作者:Jeffrey C. Holder、Emmett D. Goodman、Kotaro Kikushima、Michele Gatti、Alexander N. Marziale、Brian M. Stoltz
DOI:10.1016/j.tet.2014.11.048
日期:2015.9
The development and optimization of a palladium-catalyzedasymmetricconjugateaddition of arylboronicacids to cyclic enone conjugateacceptors is described. These reactions employ air-stable and readily-available reagents in an operationally simple and robust transformation that yields β-quaternary ketones in high yields and enantioselectivities. Notably, the reaction itself is highly tolerant of
Sodium Tetraarylborates as Effective Nucleophiles in Rhodium/Diene-Catalyzed 1,4-Addition to β,β-Disubstituted α,β-Unsaturated Ketones: Catalytic Asymmetric Construction of Quaternary Carbon Stereocenters
A rhodium-catalyzed1,4-addition of sodium tetraarylborates to beta,beta-disubstituted alpha,beta-unsaturated ketones is described. Highly efficient asymmetric catalysis has also been achieved by employing a readily available chiral diene ligand, leading to the construction of quaternary carbon stereocenters with high enantioselectivity.
Chiral Tetrafluorobenzobarrelenes as Effective Ligands for Rhodium-Catalyzed Asymmetric 1,4-Addition of Arylboroxines to β,β-Disubstituted α,β-Unsaturated Ketones
and Two Smoking Barrelenes: The rhodium‐catalyzed 1,4‐addition of readily available arylboronic acid anhydrides to simple β,β‐disubstituted α,β‐unsaturated ketones creates quaternary carbon stereocenters with high enantiomeric excesses using a chiraltetrafluorobenzobarreleneligand.
Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Five-, Six-, and Seven-Membered β-Substituted Cyclic Enones: Enantioselective Construction of All-Carbon Quaternary Stereocenters
作者:Kotaro Kikushima、Jeffrey C. Holder、Michele Gatti、Brian M. Stoltz
DOI:10.1021/ja200664x
日期:2011.5.11
The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters via 1,4-addition of arylboronic acids to β-substituted cyclic enones is reported. Reaction of a wide range of arylboronic acids and cyclic enones using a catalyst prepared from Pd(OCOCF(3))(2) and a chiral pyridinooxazoline ligand yields enantioenriched products bearing benzylic stereocenters. Notably, this