29912-44-5Relevant academic research and scientific papers
Mechanism-Inspired Design of Bifunctional Catalysts for the Alternating Ring-Opening Copolymerization of Epoxides and Cyclic Anhydrides
Abel, Brooks A.,Lidston, Claire A. L.,Coates, Geoffrey W.
, p. 12760 - 12769 (2019)
Advances in catalysis have enabled the ring-opening copolymerization of epoxides and cyclic anhydrides to afford structurally and functionally diverse polyesters with controlled molecular weights and dispersities. However, the most common systems employ b
Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Catalyzed by Rare-Earth Amides [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 with Phenoxy-Functionalized Chiral Prolinols
Zeng, Chao,Yuan, Dan,Zhao, Bei,Yao, Yingming
supporting information, p. 2242 - 2245 (2015/05/13)
A simple and efficient catalytic enantioselective epoxidation of α,β-unsaturated ketones has been successfully developed, which was catalyzed by rare-earth metal amides [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 (RE = Yb (1), La (2), Sm (3), Y (4), Lu (5)) in the presence of phenoxy-functionalized chiral prolinols at room temperature using tert-butylhydroperoxide (TBHP) as the oxidant. The combination of an Yb-based amide 1 and a chiral proligand (S)-2,4-di-tert-butyl-6-((2-(hydroxydiphenylmethyl)pyrrolidin-1-yl)methyl)phenol) performed very well, and both the yields and the enantiomeric excess of the chiral epoxides reached up to 99% and 99% ee. (Figure Presented).
Facile and efficient enantioselective strecker reaction of ketimines by chiral sodium phosphate
Shen, Ke,Liu, Xiaohua,Cai, Yunfei,Lin, Lili,Feng, Xiaoming
supporting information; experimental part, p. 6008 - 6014 (2010/02/28)
A facile and efficient enantioselective Strecker reaction of ketimines catalyzed by a chiral alkali-metal salt has been developed. When 10 mol% BNPNa (BNP=1,1'-binaphthyl-2,2'-diylphosphate) prepared in situ and 10 mol% para-tert-butylortho-adamantylphenol (PBAP) were introduced into the reaction, up to 96% yield and up to 95% ee (ee=enantiomeric excess) were obtained. Both aliphatic and aromatic ketimines, especially sterically bulky cyclic ketimines derived from β-acetonaphthone, α-indanone, and α-tetralone were found suitable for this reaction. On the basis of the experimental results and previous reports, trimethylsilyl cyanide (TMSCN) was indicated to be the real reactive nucleophile despite the existence of PBAP, and a possible working model was proposed to explain the origin of the asymmetric induction. The facile availability of 1,1'-binaphthyl-2,2'-diylphosphoric acid (BNPH) and the simplicity of the procedure are beneficial for practical applications.
Co-metal-free enantioselective conjugate addition reactions of zinc reagents
Ay, Sefer,Nieger, Martin,Braese, Stefan
experimental part, p. 11539 - 11556 (2009/12/07)
Asymmetric conjugate addition of diethylzinc to cinnamaldehyde in a co-metal-free fashion by using N,O-ligands with planar and central chirality is described. Different modulations of the ligand structure, including several combinations of the chiral units, indicate that a [2.2]paracyclophane backbone is essential for the activity and the enantioselectivity of the generated active catalyst. By using the optimized ligand, an isolated yield of 90 % was obtained with up to 99 % ee.
Ring-opening polymerization of lactide with group 3 metal complexes supported by dianionic alkoxy-amino-bisphenolate ligands: Combining high activity, productivity, and selectivity
Amgoune, Abderramane,Thomas, Christophe M.,Roisnel, Thierry,Carpentier, Jean-Francois
, p. 169 - 179 (2007/10/03)
A series of new alkoxy-amino-bis(phenols) (H2L 1-6) has been synthesized by Mannich condensations of substituted phenols, formaldehyde, and amino ethers or diamines. The coordination properties of these dianionic ligands towards yttrium, lantha
