191725-62-9Relevant 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)
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.
Nickel-Catalyzed Desymmetric Hydrogenation of Cyclohexadienones: An Efficient Approach to All-Carbon Quaternary Stereocenters
You, Cai,Li, Xiuxiu,Gong, Quan,Wen, Jialin,Zhang, Xumu
supporting information, p. 14560 - 14564 (2019/10/11)
Nickel-catalyzed desymmetric hydrogenation has been achieved. With the Ni(OTf)2/(S,S)-Ph-BPE system, a series of ?,?-disubstituted cyclohexadienones were transformed to the corresponding cyclohexenones with a chiral all-carbon quaternary center at the γposition in high yields (92-98%) and excellent enantioselectivities (92%-99% ee). This catalytic system can also tolerate the desymmetric reaction of spirocarbocyclic cyclohexadienones to produce the corresponding cyclohexenones bearing a chiral spiro quaternary carbon with high yields (94%-98%) and ee values (96%-99% ee). Furthermore, this methodology provides an efficient and concise synthetic route to the intermediate of natural products cannabispirenones A and B.
Dynamic kinetic asymmetric amination of alcohols: From a mixture of four isomers to diastereo- and enantiopure α-branched amines
Rong, Zi-Qiang,Zhang, Yao,Chua, Raymond Hong Bing,Pan, Hui-Jie,Zhao, Yu
supporting information, p. 4944 - 4947 (2015/05/05)
The first dynamic kinetic asymmetric amination of alcohols via borrowing hydrogen methodology is presented. Under the cooperative catalysis by an iridium complex and a chiral phosphoric acid, α-branched alcohols that exist as a mixture of four isomers undergo racemization by two orthogonal mechanisms and are converted to diastereo- and enantiopure amines bearing adjacent stereocenters. The preparation of diastereo- and enantiopure 1,2-amino alcohols is also realized using this catalytic system.
