The first nickel-catalyzed desymmetric hydrogenation has been achieved. With the Ni(OTf)2/(S,S)-Ph-BPE system, a series of γ,γ-disubstituted cyclohexadienones were transformed to the corresponding cyclohexenones with a chiral all-carbon quaternary center at the γ position in high yields (92% to 98%) and excellent enantioselectivities (92% to 99% ee). This catalytic system can also tolerate the desymmetric
首次实现了镍催化的不对称氢化。使用 Ni(OTf)2/(S,S)-Ph-BPE 系统,一系列 γ,γ-二取代环己二烯酮以高产率转化为相应的环己烯酮,其在 γ 位具有手性全碳四元中心( 92% 至 98%)和出色的对映选择性(92% 至 99% ee)。该催化体系还可以耐受螺碳环环己二烯酮的去对称反应,以产生相应的带有手性螺季碳的环己烯酮,收率高(94% 至 98%)和 ee 值(96% 至 99% ee)。此外,该方法为天然产物大麻吡酮 A 和 B 的中间体提供了一种高效、简洁的合成路线。
Asymmetric organocatalytic desymmetrization of 4,4-disubstituted cyclohexadienones at high pressure: a new powerful strategy for the synthesis of highly congested chiral cyclohexenones
A highly diastereoselective and enantioselective method for the asymmetric desymmetrization of 4,4-disubstituted cyclohexadienones using the Michael addition reaction of malonates under catalysis with the primary amine-thiourea conjugate catalyst and PPY at high pressure was developed.
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。
Palladium(0)-Catalyzed Arylative Dearomatization of Phenols
作者:Sophie Rousseaux、Jorge García-Fortanet、Miguel Angel Del Aguila Sanchez、Stephen L. Buchwald
DOI:10.1021/ja203644q
日期:2011.6.22
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).
KRISHNA, K. V. RAMA;SUJATHA, K.;KAPIL, R. S., TERAHEDRON LETT., 31,(1990) N, C. 1351-1352