Synlett 2005(10): 1591-1595  
DOI: 10.1055/s-2005-869862
LETTER
© Georg Thieme Verlag Stuttgart · New York

Novel Dendritic Ligands of Chiral 1,2-Diamine and Their Application in Asymmetric Hydrogenation of Simple Aryl Ketones

Weiguo Liua,c, Xin Cuia, Linfeng Cuna, Jun Wua, Jin Zhua, Jingen Deng*a,c, Qinghua Fanb
a Key Laboratory of Asymmetric Synthesis & Chirotechnology of Sichuan Province and Union Laboratory of Asymmetric Synthesis, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, P. R. China
b Laboratory of Chemical Biology, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, P. R.China
c Graduate School of the Academy of Sciences, Beijing, P. R. China
Fax: +86(28)85223978; e-Mail: jgdeng@cioc.ac.cn;
Further Information

Publication History

Received 23 March 2005
Publication Date:
07 June 2005 (online)

Abstract

Novel dendritic chiral vicinal diamine ligands have been synthesized and a series of dendritic Ru(BINAP)(diamine) catalysts were developed for asymmetric hydrogenation of a variety of ­simple aryl ketones in good catalytic activity and high enantioselectivity, as well as facile catalyst recycling. An increase of enantio­selectivities was obtained by using the dendritic catalysts compared with Noyori catalysts under the same conditions in the case of ­several substrates. Meanwhile, a remarkable structural effect on ­catalytic activity and enantioselectivity, as well as reuse was ­observed.

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ESI-HRMS data for the dendritic ligands.
Ligand (S,S)-7a: m/z calcd for C28H28N2O2: 424.2151; found: 424.1915.
Ligand (S,S)-7b: m/z calcd for C56H54KN2O6 [M + K + 2 H]: 889.3619; found: 889.4199; C56H50NO6 [M - NH2]: 832.3638; found: 832.3673.
Ligand (S,S)-7c: m/z calcd for C112H101N2NaO14 [M + Na + H] (MALDI-TOF): 1719.7; found: 1720.1.
Ligand (S,S)-7d: m/z calcd for C224H203N2NaO30 [M + Na + 7 H] (MALDI-TOF): 3423.4: found: 3423.4.