作者:Aditya L. Gottumukkala、Kiran Matcha、Martin Lutz、Johannes G. de Vries、Adriaan J. Minnaard
DOI:10.1002/chem.201200694
日期:2012.5.29
An efficient palladium catalyst is presented for the formation of benzylic quaternarystereocenters by conjugate addition of arylboronic acids to a variety of β,β‐disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and provides products in up to 99 % enantiomeric excess, with good yields. Based on this strategy, (−)‐α‐cuparenone
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
Palladium-Catalyzed Conjugate Addition of Arylboronic Acids to β,β-Disubstituted Enones in Aqueous Media: Formation of Bis-benzylic and <i>ortho</i>-Substituted Benzylic Quaternary Centers
作者:Ryan Van Zeeland、Levi M. Stanley
DOI:10.1021/acscatal.5b01272
日期:2015.9.4
Palladium-catalyzed conjugate addition of arylboronic acids to β,β-disubstituted enones in aqueousmedia is reported. Additions of a wide range of arylboronic acids to β,β-disubstituted enones occur to form ketone products bearing benzylic all-carbon quaternary centers. These reactions are promoted by a simple catalyst prepared from palladium trifluoracetate and 2,2′-bipyridine. The use of aqueous sodium trifluoracetate
Efficient Formation of Benzylic Quaternary Centers via Palladium Catalysis
作者:Aditya L. Gottumukkala、Jasmin Suljagic、Kiran Matcha、Johannes G. de Vries、Adriaan J. Minnaard
DOI:10.1002/cssc.201300276
日期:2013.9
Four′s a crowd: An efficient protocol for the formation of benzylicquaternarycentersvia arylation of enones using a catalyst made from Pd(O2CCF3)2 and 2,2′‐bipyridine is developed. For cyclic substrates, catalyst loadings as low as 1 mol % Pd are enough to afford excellent yields (>90 %) using a variety of arylboronic acids. In case of acyclic substrates, the addition of KSbF6 was found to improve
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