Development of an axially chiral sp3P/sp3NH/sp2N-combined linear tridentate ligand-fac-selective formation of Ru(II) complexes and application to ketone hydrogenation

TETRAHEDRON

卷:72

Article

Yamamura, Tomoya¹  Nakane, Satoshi¹  Nomura, Yuko¹  Tanaka, Shinji¹  Kitamura, Masato¹ 

[1] Nagoya Univ, Res Ctr Mat Sci, Grad Sch Pharmaceut Sci,Grad Sch Sci, Chikusa Ku, Nagoya, Aichi 4648601, Japan

关键词: Chiral ligand;    Tridentate;    fac-Ru complex;    Catalysis;    Hydrogenation;   

DOI  :  10.1016/j.tet.2016.02.007

来源: Elsevier

【 摘 要 】

A newly developed chiral linear tridentate ligand, R-PN(H)N (R=H or Ph), possesses Ph2P and PyCH2NH groups at C(2) and C(2') positions of the 1,1'-binaphthyl skeleton without or with a C(3)-Ph substituent. The steric effect of C(3)-Ph and the electronic effect of the DMSO co-ligand realize the facial selective generation of fac-RuCl2(Ph-PN(H)N)(dmso) and fac-[Ru(H-PN(H)N)(dmso)(3)](BF4)(2), respectively. Both an H-Ru center dot center dot center dot sp(3)N-H reaction site responsible for the donor acceptor bifunctional catalyst (DACat) and a fence/plane chiral context were constructed by means of the following advantageous points: i) the sp(3)P, sp(3)N, and sp(2)N ligating atoms have different electronic properties; ii) DMSO trans to sp(3)N strongly coordinates to Ru and is fixed by a PyC(6)H center dot center dot center dot O=S hydrogen bond; and iii) the single NH function simplifies the DACat reaction site. The synergistic effect has led to success in the asymmetric hydrogenation of sterically demanding ketones. Structural characteristics of first-row transition metal complexes of R-PN(H)N have been also investigated. (C) 2016 Elsevier Ltd. All rights reserved.

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