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.
Rhodium-Catalyzed Asymmetric 1,4-Addition of Aryl Alanes to Trisubstituted Enones: Binap as an Effective Ligand in the Formation of Quaternary Stereocenters
All for one and 1,4‐all: Readily available arylalanes are used in the rhodium‐catalyzed asymmetric conjugate addition reaction with a variety of cyclic and acyclic enones. The enhanced reactivity of the system allows the use of the common binapligand for the generation of quaternary benzylic stereocenters in excellent enantioselectivity (see scheme).
Enantioselective construction of <i>ortho</i>-substituted benzylic quaternary centers using a phenanthroline-Pd catalyst
作者:Masafumi Tamura
DOI:10.1039/d2ob01743a
日期:——
addition of ortho-substituted arylboronic acids to cyclic enones was developed. The addition of various ortho-substituted arylboronic acid to β-substituted cyclic enones, via catalysis with a chiral phenanthroline-Pd complex, formed cyclic ketone products bearing ortho-substituted benzylic all-carbon quaternarycenters with good yields and high enantioselectivity.