Palladium(0)-Catalyzed Arylative Dearomatization of Phenols
摘要:
The palladium-catalyzed arylative dearomatization of phenols to yield spirocyclohexadienone products in good to excellent yields has been developed. Preliminary results demonstrate that the formation of the spirocyclic all-carbon quaternary center can be accomplished with high levels of enantiocontrol (up to 91% ee).
Asymmetric Synthesis of Remote Quaternary Centers by Copper-Catalyzed Desymmetrization: An Enantioselective Total Synthesis of (+)-Mesembrine
作者:Apparao Bokka、James X. Mao、John Hartung、Steven R. Martinez、Justin A. Simanis、Kwangho Nam、Junha Jeon、Xiaoqiang Shen
DOI:10.1021/acs.orglett.8b02084
日期:2018.9.7
Catalytic asymmetric syntheses of remote quaternary stereocenters have been developed by copper-catalyzed 1,4-hydrosilylation of γ,γ-disubstituted cyclohexadienones. A variety of cyclohexenones have been synthesized in good yield and excellent enantioselectivity. Versatile 2-silyloxy diene intermediates bearing γ,γ-disubstituted all carbon stereogenic centers can be isolated from the mild reaction
the corresponding cyclohexenones 4 with a remote chiral all‐carbon quaternary center at the γ position is described. Chiral rhodium–bis(oxazolinyl)phenyl complexes 1 were effective catalysts for this transformation. This catalytic system was extended to the asymmetric transformation of spirocarbocyclic cyclohexadienones 5 to give the corresponding products 6 with highenantiomeric ratios.
Silver-Catalyzed Asymmetric Desymmetrization of Cyclohexadienones via Van Leusen Pyrrole Synthesis
作者:Mohamed Ahmed Abozeid、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.2c00240
日期:2022.3.11
catalytic asymmetric desymmetrization of cyclohexadienones was accomplished via Van Leusen pyrrole synthesis in the presence of a chiral silver catalyst. The ready access to chiral-fused pyrrole derivatives is attributed to the identification of a suitable isocyanomethyl sulfone surrogate, NasMIC. The current Ag(I)–chiral phosphino-carboamide ligand system can be extended to the kinetic resolution
在手性银催化剂存在下,通过 Van Leusen 吡咯合成实现了环己二烯酮的催化不对称去对称化。易于获得手性稠合吡咯衍生物归因于合适的异氰基甲基砜替代物 NasMIC 的鉴定。目前的 Ag(I)-手性膦基-碳酰胺配体系统可以扩展到外消旋环己二烯酮的动力学拆分,利用来自 AgSbF 6、手性配体 ( L *)、环己二烯酮和 NasMIC 的手性四元配合物的不同反应性。
Rhodium-Catalyzed Desymmetric Arylation of <i>γ,γ</i>-Disubsituted Cyclohexadienones: Asymmetric Synthesis of Chiral All-Carbon Quaternary Centers
作者:Yu Qiao、Shiming Bai、Xiao-Feng Wu、Ying Yang、He Meng、Jialin Ming
DOI:10.1021/acs.orglett.2c00225
日期:2022.2.25
desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (R)-segphos–rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the β-position and a chiral all-carbon quaternary center at the γ-position, with high diastereo- and enantioselectivities. This catalytic system was also applied to the arylation of spirocarbocyclic
在 ( R )-segphos-铑催化剂存在下,前手性环己二烯酮与 ArZnCl 的不对称芳基化得到高产率的相应环己烯酮,其在β位含有手性芳基化碳中心,在γ-位,具有高非对映选择性和对映选择性。该催化体系还应用于螺碳环环己二烯酮的芳基化,并提供了相应的带有高 dr 和 ee 的手性螺季碳的环己烯酮。
Desymmetrization of Cyclohexadienones Containing a Quaternary γ-Carbon Atom by Conjugate Addition of Boron Nucleophiles
作者:Zhi-Yuan Zhao、Ming Cui、Anne A. Poletti、Elisabeth Irran、Martin Oestreich
DOI:10.1021/acscatal.3c04725
日期:2024.1.5
A highlyenantio- and diastereoselective copper-catalyzed conjugate monoborylation of γ,γ-disubstituted cyclohexadienone derivatives is reported. Two contiguous stereocenters are generated in this group-selective reaction, one at the formed boron-bearing carbon atom in a neopentylic position and one at the quaternary carbon atom. A subsequent 1,4-addition of a boron nucleophile to the remaining α,β-unsaturated