1035598-68-5Relevant academic research and scientific papers
Efficient asymmetric oxidation of sulfides and kinetic resolution of sulfoxides catalyzed by a vanadium-salan system
Sun, Jiangtao,Zhu, Chengjian,Dai, Zhenya,Yang, Minghua,Pan, Yi,Hu, Hongwen
, p. 8500 - 8503 (2004)
The asymmetric oxidation of sulfides to chiral sulfoxides with hydrogen peroxide in good yield and high enantioselectivity has been catalyzed very effectively by chiral vanadium-salan [N,N′-alkyl bis(salicylamine)] complex. The salan ligand shows results superior in terms of reactivity and enantioselectivity to those of salen [N,N′-alkylene bis(salicylideneimine) ] analogue, and provides the sulfoxide with opposite configuration. The high enantioselectivity of this reaction is the direct result of the asymmetric oxidation. The efficient kinetic resolution of racemic sulfoxides catalyzed by the vanadium-salan system is also described.
Group 4 metal complexes with new chiral pincer NHC-ligands: Synthesis, structure and catalytic activity
Zhao, Ning,Hou, Guohua,Deng, Xuebin,Zi, Guofu,Walter, Marc D.
, p. 8261 - 8272 (2014/06/09)
Chiral group 4 NHC-metal complexes were prepared in good yields by amine elimination from M(NR2)4 (M = Ti, Zr, Hf; R = Me, Et) and chiral pincer NHC-ligands, L4 (L4a and L4b), L5 and L6, which are derived from (S,S)-diphenyl-1,2-ethanediamine. Treatment of M(NR2)4 with 1 equiv. of L4 in THF gives, after recrystallization from a benzene solution, the chiral titanium amides (L4)Ti(NMe2)(Br)(THF) (7) and (L4)Ti(NMe2)(Cl)(THF) (11), zirconium amides (L4)Zr(NMe 2)(Br)(THF) (8), (L4)Zr(NEt2)(Br)(THF) (10), (L4)Zr(NMe2)(Cl)(THF) (12) and (L4)Zr(NEt2)(Cl)(THF) (14), and hafnium amides (L4)Hf(NMe2)(Br)(THF) (9) and (L4)Hf(NMe 2)(Cl)(THF) (13), respectively. Similarly, the reactions of L5 or L6 with 1 equiv. of M(NR2)4 yield the titanium amide (L6)Ti(NMe2)(Cl)(THF) (16), the zirconium amides (L5)Zr(NMe 2)(Cl)(THF) (15), (L6)Zr(NMe2)(Cl)(THF) (17) and (L6)Zr(NEt2)(Cl)(THF) (19), and the hafnium amide (L6)Hf(NMe 2)(Cl)(THF) (18), respectively. Complexes 7-19 were characterized by various spectroscopic techniques and elemental analyses. The molecular structures of 10 and 14-19 were also established by X-ray diffraction analyses, which represent the first example of the structurally characterized group 4 chiral NHC-metal complex. Furthermore, 7-19 are active catalysts for the polymerization of rac-lactide in the presence of isopropanol, leading to the heterotactic-rich polylactides. the Partner Organisations 2014.
