Journal of University of Chinese Academy of Sciences >
Application of Chiral Ferrocene Ligands in Asymmetric Palladium Catalyzed Allylic Substitution Reactions
Received date: 2003-11-27
Online published: 2004-05-10
Thioether, selenide and phosphino derivatives of ferrocenyl oxazolines, synthesized from ferrocenyl oxazolines, were found to be effective in palladium catalyzed allylic alkylation with up to 99% ee. With P, N ligand, palladium catalyzed allylic amination was achieved with 97% ee. The enantio control was dominated by the central chirality. However, the match between planar chirality and central chirality is critical for high enantioselectivity. A series of planar chiral ferrocene modified bisphosphine pocket ligands were synthesized and found to be very effective in construction of quaternary carbon centers using asymmetric allylic alkylation. Some non coded alpha, alpha disubstituted amino acids were obtained with up to 75% ee using ketone imino esters. Using enolate of simple ketone as nucleophile, alpha, alpha disubstituted ketones were obtained with up to 95% ee. A new type of ferrocene based P, N ligands has been synthesized and was found to be very effective in regio and enantio selective palladium catalyzed allylic alkylation and amination of mono substituted allylic acetates. The free OH in the ligand was very important for selective control by the hydrogen bonding with benzylamine in later reaction, which was proved by experimental results.
Key words： asymmetric catalysis; ferrocene; planar chirality
YOU ShuLi , HOU XueLong , DAI LiXin . Application of Chiral Ferrocene Ligands in Asymmetric Palladium Catalyzed Allylic Substitution Reactions[J]. Journal of University of Chinese Academy of Sciences, 2004 , 21(3) : 413 -417 . DOI: 10.7523/j.issn.2095-6134.2004.3.021
[1] Li-Xin Dai, Xue-Long Hou, Wei-Ping Deng, Shu-Li You, Yong-Gui Zhou. The application of ligands with planar chirality in asymmetric synthesis. Pure Appl. Chem., 1999, 71: 1401-1405
[2] Li-Xin Dai, Tao Tu, Shu-Li You, Wei-Ping Deng, Xue-Long Hou. Asymmetric catalysis with chiral ferrocene ligands. Acc. Chem. Res., 2003,36: 659-667
[3] Shu-Li You, Yong-Gui Zhou, Xue-Long Hou, Li-Xin Dai. Enantioselective palladium catalyzed allylic substitution with chiral thioether derivatives of ferrocenyl-oxazoline and the role of planar chirality in this reaction.Chem. Commun., 1998, 2765-2766
[4] Shu-Li You, Xue-Long Hou, Li-Xin Dai. Synthesis of planar chiral selenide derivatives of ferrocenyl-oxazoline and their application in enantioselective palladium catalyzed allylic substitution reaction.Tetrahedron : Asymmetry, 2000, 11:1495-1500
[5] Shu-Li You, Xue-Long Hou, Li-Xin Dai, Yi-Hua Yu, Wei Xia. Role of planar chirality of S, N-and P, N-ferrocene ligands in palladium-catalyzed allylic substitutions. J. Org. Chem., 2002, 67: 4684-4695
[6] Shu-Li You, Xue-Long Hou, Li-Xin Dai, Bo-Xun Cao, Jie Sun. Novel bis-N-[2-(diphenylphosphino)-ferrocenylcarbonyl] diaminocyclohexane ligands: application in asymmetric allylic alkylation of imino esters with simple allyl carbonate.Chem. Commun., 2000, 1933-1934
[7] Shu-Li Yo, Xue-Long Hou, Li-Xin Dai, Xia-Zhen Zhu. Highly efficient ligandsfor palladium-catalyzed asymmetric alkylationof ketone enolates.Org. Lett., 2001, 3: 149-151
[8] Shu-Li You, Xia-Zhen Zhu, Xue-Long Hou, Li-Xin Dai. Synthesisof new diphosphine ligands and their applications in palladium-catalyzed allylic alkylation to construct chiral quaternary carbon center. Huaxue Xuebao, 2001, 59: 1667-1674
[9] Shu-Li You, Xue-Long Hou, Li-Xin Dai. Novel ferrocene modified P, N-ligands for enantioselective palladium-catalyzed allylic substitution reactions. J. Organometallic Chem., 2001, 637639: 762-766
[10] Shu-Li You, Yu-Mei Luo, Wei-Ping Deng, Xue-Long Hou, Li-Xin Dai. Palladium-catalyzed asymmetric allylic alkylationsof cycloalkenyl acetates with planar chiral phosphino-ferrocene carboxylic acids. J. Organometallic Chem., 2001, 637-639: 845-849
[11] Shu-Li You, Xia-Zhen Zhu, Yu-Mei Luo, Xue-Long Hou, Li-Xin Dai. Highly regio-and enantioselective Pd-catalyzed allylic alkylation and amination of monosubstituted allylic acetates with novel ferrocene P,N-ligands. J. Am. Chem. Soc., 2001, 123: 7471-7472
[12] Wei-Ping Deng, Shu-Li You, Xue-Long Hou, Li-Xin Dai, Yi-Hua Yu, Wei Xia, Jie Sun. Importance of planar chirality in chiral catalysts with three chiral elements: the role of planar chirality in 2'-substituted21,1'-P, N-ferrocene ligands on the enantioselectivity in Pd2catalyzed allylic substitution. J. Am. Chem. Soc., 2001, 123: 6508-6519
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