Synthesis of an Optically Active Al(salalen) Complex and Its Application to Catalytic Hydrophosphonylation of Aldehydes and Aldimines
作者:Bunnai Saito、Hiromichi Egami、Tsutomu Katsuki
DOI:10.1021/ja0651005
日期:2007.2.1
serve as an efficient catalyst for hydrophosphonylation of aldehydes and aldimines, giving the corresponding alpha-hydroxy and alpha-amino phosphonates with high enantioselectivity, respectively. The scope of the hydrophosphonylation was wide, and both aliphatic and aromatic aldehydes and aldimines were successfully used as substrates for the reaction. The potent catalysis of the complex is attributed to
unsymmetrical salan fluorescentsensors 2a and 2b have been designed and synthesized. The chiral recognition of N-Boc-protectedaminoacids by 2a and 2b has been investigated. Sensor 2a possesses higher sensitivity and enantioselectivity than sensor 2b does. Job analysis and nonlinear regression results show that 2a can form a 1:1 stoichiometric complex with a N-Boc-protectedaminoacid. The obtained response
Enantioselective Resolution Copolymerization of <i>Racemic</i> Epoxides and Anhydrides: Efficient Approach for Stereoregular Polyesters and Chiral Epoxides
作者:Jie Li、Bai-Hao Ren、Zhao-Qian Wan、Shi-Yu Chen、Ye Liu、Wei-Min Ren、Xiao-Bing Lu
DOI:10.1021/jacs.9b02722
日期:2019.6.5
strategy for preparing isotactic polyesters and chiral epoxides via enantioselective resolution copolymerization of racemic terminal epoxides with anhydrides, mediated by enantiopure bimetallic complexes in conjunction with a nucleophilic cocatalyst. The chirality of both the axial linker and the diamine backbones of the ligand are responsible for the chiral induction of this kinetic resolution copolymerization
A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
作者:David E. White、Pamela M. Tadross、Zhe Lu、Eric N. Jacobsen
DOI:10.1016/j.tet.2014.03.043
日期:2014.7
enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen) Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminalepoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of
The effect of chiral <i>N</i>-substituents with methyl or trifluoromethyl groups on the catalytic performance of mono- and bifunctional thioureas
作者:Josué Vazquez-Chavez、Socorro Luna-Morales、Diego A. Cruz-Aguilar、Howard Díaz-Salazar、Wilmer E. Vallejo Narváez、Rodrigo S. Silva-Gutiérrez、Simón Hernández-Ortega、Tomás Rocha-Rinza、Marcos Hernández-Rodríguez
DOI:10.1039/c9ob01893j
日期:——
thiourea organocatalysts that incorporate a chiral group which includes a trifluoromethyl moiety and contrasted their performance with non-fluorinated analogs. The comparison between such systems allows the direct study of the NH acidity of a thiourea bonded to an aliphatic substituent. In principle, –CF3 systems feature an enhanced hydrogen bond (HB) donor capacity that is undoubtedly beneficial for