1284451-83-7Relevant articles and documents
Chiral electron-rich PNP ligand with a phospholane motif: Structural features and application in asymmetric hydrogenation
Wang, Heng,Zhang, Yao,Yang, Tilong,Guo, Xiaochong,Gong, Quan,Wen, Jialin,Zhang, Xumu
supporting information, p. 8796 - 8801 (2020/11/13)
Despite the remarkable reactivity that was achieved by a series of transition-metal catalysts with a PNP type ligand, the electron-rich chiral PNP ligands have still been rarely reported because of the difficulties in synthesis and the nature of air-sensitivity. Herein, we report a novel chiral PNP ligand (Heng-PNP) with both a rigid backbone and a bulky tert-butyl group on the phospholane motif. We successfully obtained its divalent iron complex. The chiral environment of its Ir(III) complex was also discussed with quadrant analysis. This tridentate ligand was applied in iridium-catalyzed asymmetric hydrogenation of challenging diaryl ketones: up to 98% ee and 500 TON are achieved. Computational study showed that the twist of conjugate aryl group in the substrate (induced by the special chiral pocket of Ir/Heng-PNP complex) leads to the energy difference in the enantiodetermining step.
Efficient palladium-catalyzed C(sp2)-H activation towards the synthesis of fluorenes
Song, Juan,Li, Yali,Sun, Wei,Yi, Chenglong,Wu, Hao,Wang, Haotian,Ding, Keran,Xiao, Kang,Liu, Chao
supporting information, p. 9030 - 9033 (2016/11/11)
A facile protocol for the synthesis of fluorene derivatives has been developed through palladium-catalyzed cyclization of 2′-halo-diarylmethanes via activation of arylic C-H bonds. The reactions occurred smoothly and allowed both electron-rich and electron-deficient substrates to convert into their corresponding fluorenes in good to excellent yields. Studies revealed that this Pd-catalyzed cyclization was also available for the substrates of 2′-chloro-diarylmethanes and no catalyst poisoning occurred for 2′-iodo-diphenylmethane.
Bismuth-catalyzed synthesis of anthracenes via cycloisomerization of o-alkynyldiarylmethane
Park, Jungmin,Choi, Hyuck,Lee, Deug-Chan,Lee, Kooyeon
supporting information, p. 7005 - 7007 (2015/11/27)
In this study, anthracenes were efficiently synthesized from o-alkynyldiarylmethane using a novel method that exploits the synergistic effect between Bi(OTf)3 as the catalyst, and trifluoroacetic acid (TFA). Through this reaction, we achieved the rapid and efficient synthesis of anthracenes bearing various functional groups under mild conditions.
Fluorenone synthesis by palladacycle-catalyzed sequential reactions of 2-bromobenzaldehydes with arylboronic acids
Liu, Tao-Ping,Liao, Yuan-Xi,Xing, Chun-Hui,Hu, Qiao-Sheng
supporting information; experimental part, p. 2452 - 2455 (2011/06/25)
Chemical equations presented. A new, anionic four-electron donor-based (type I) palladacycle-catalyzed sequential reaction of 2-bromobenzaldehydes with arylboronic acids based on the addition reaction, cyclization via C-H activation-oxidation sequence is described. Our study provided an efficient access to a variety of substituted fluorenones/indenofluorenediones from readily available arylboronic acids and 2-bromobenzaldehydes.