24432-28-8Relevant academic research and scientific papers
Asymmetric Synthesis of Remote Quaternary Centers by Copper-Catalyzed Desymmetrization: An Enantioselective Total Synthesis of (+)-Mesembrine
Bokka, Apparao,Mao, James X.,Hartung, John,Martinez, Steven R.,Simanis, Justin A.,Nam, Kwangho,Jeon, Junha,Shen, Xiaoqiang
, p. 5158 - 5162 (2018/09/13)
Catalytic asymmetric syntheses of remote quaternary stereocenters have been developed by copper-catalyzed 1,4-hydrosilylation of ?,?-disubstituted cyclohexadienones. A variety of cyclohexenones have been synthesized in good yield and excellent enantioselectivity. Versatile 2-silyloxy diene intermediates bearing ?,?-disubstituted all carbon stereogenic centers can be isolated from the mild reaction conditions. The utility of this strategy is exemplified in a catalytic asymmetric total synthesis of (+)-mesembrine.
Catalytic Desymmetrizing Dehydrogenation of 4-Substituted Cyclohexanones through Enamine Oxidation
Zhu, Lihui,Zhang, Long,Luo, Sanzhong
supporting information, p. 2253 - 2258 (2018/02/09)
A desymmetrizing dehydrogenation process catalyzed by a chiral primary amine is described herein. The reaction proceeds through the oxidation of a ketone enamine by IBX and enables the highly enantioselective desymmetrization of 4-substituted cyclohexanones with the generation of chiral 4-substituted cyclohexenones containing a remote γ-stereocenter.
Enantioselective Conversion of Achiral Cyclohexadienones to Chiral Cyclohexenones by Desymmetrization
Han, Yixin,Breitler, Simon,Zheng, Shao-Liang,Corey
supporting information, p. 6172 - 6175 (2016/12/09)
The enantioselective reduction of prochiral 4,4-disubstituted 2,5-cyclohexadienones to chiral 2-cyclohexenones has been accomplished by the use of a carefully selected chiral bisphosphine-CuI complex and diisobutylaluminum hydride-hexamethylphosphoric triamide complex. This reagent has provided access to a key bicyclic intermediate for the total synthesis of the natural enantiomer of the pentacyclic sesterterpene retigeranic acid that involves spatial discrimination between CH3 and CH2CH2R substituents, an operation that has been elusive previously. In addition, a second method for desymmetrization is described using catalytic enantioselective [4 + 2]-cycloaddition of cyclopentadiene to prochiral 4,4-disubstituted 2,5-cyclohexadienones.
Asymmetric Induction at Remote Quaternary Centers of Cyclohexadienones by Rhodium-Catalyzed Conjugate Hydrosilylation
Naganawa, Yuki,Kawagishi, Mayu,Ito, Jun-Ichi,Nishiyama, Hisao
, p. 6873 - 6876 (2016/06/13)
The enantioselective desymmetrizing conjugate hydrosilylation of prochiral differently γ,γ-disubstituted cyclohexadienone derivatives 2 to furnish the corresponding cyclohexenones 4 with a remote chiral all-carbon quaternary center at the γ position is de
A new powerful strategy for the organocatalytic asymmetric construction of a quaternary carbon stereogenic center
Lnokoishi, Yogo,Sasakura, Niiha,Nakano, Keiji,Ichikawa, Yoshiyasu,Kotsuki, Hiyoshizo
supporting information; experimental part, p. 1616 - 1619 (2010/06/17)
(Figure Presented) A new method for chiral diamine-catalyzed Robinson-type annulation was developed to construct cyclohexenone derivatives bearing a quaternary carbon stereogenic center at the 4-position in high enantiomeric excess. This method was successfully applied to the short synthesis of (+)-sporochnol A.
An Asymmetric Synthesis of Chiral 4,4-Disubstituted Cyclohexenones in High Enantiomeric Purity
Meyers, A. I.,Lefker, Bruce A.,Wanner, Klaus Th.,Aitken, R. Alan
, p. 1936 - 1938 (2007/10/02)
An efficient approach to the title compounds in > 95percent ee has been accomplished by metalation and alkylation of chiral bicyclic lactams derived from δ-keto acids and (1S,2S)-2-amino-1-phenyl-1,3-propanediol.
