<i>C</i><sub>2</sub>-Symmetric Recyclable Organocatalyst for Enantioselective Strecker Reaction for the Synthesis of α-Amino Acid and Chiral Diamine- an Intermediate for APN Inhibitor
作者:S. Saravanan、Arghya Sadhukhan、Noor-ul H. Khan、Rukhsana I. Kureshy、Sayed H. R. Abdi、Hari C. Bajaj
DOI:10.1021/jo300349f
日期:2012.5.4
Recyclable chiral amide-based organocatalyst 5 efficiently catalyzed asymmetric Streckerreaction of various aromatic and aliphatic N-benzhydrylimines with ethyl cyanoformate as cyanide source at −10 °C to give a high yield (95%) of α-aminonitriles with excellent chiral induction (ee, up to 99%) with the added advantage of recyclability. Based on experimental observations a probable mechanism was proposed
Access to α-Arylglycines by Umpolung Carboxylation of Aromatic Imines with Carbon Dioxide
作者:Chun-Xiao Guo、Wen-Zhen Zhang、Hui Zhou、Ning Zhang、Xiao-Bing Lu
DOI:10.1002/chem.201604623
日期:2016.11.21
straightforward and transition‐metal‐free approach for the efficient synthesis of α‐arylglycine derivatives from aromatic imines and carbondioxide was enabled by an umpolung carboxylation reaction. Various substituted diphenylmethimines underwent the carboxylation smoothly with carbondioxide in the presence of potassium tert‐butoxide and 18‐crown‐6 to give the corresponding carboxylated products in good to high
Highly Enantioselective Titanium-Catalyzed Cyanation of Imines at Room Temperature
作者:Abdul Majeed Seayad、Balamurugan Ramalingam、Kazuhiko Yoshinaga、Takushi Nagata、Christina L. L. Chai
DOI:10.1021/ol902540h
日期:2010.1.15
A highly active and enantioselective titanium-catalyzed cyanation of imines at roomtemperature is described. The catalyst used is a partially hydrolyzed titanium alkoxide (PHTA) precatalyst together with a readily available N-salicyl-β-aminoalcohol ligand. Up to 98% ee was obtained with quantitative yields in 15 min of reaction time using 5 mol % of the catalyst. Various N-protecting groups such as
Diastereoselective and Enantiospecific Synthesis of 1,3-Diamines via 2-Azaallyl Anion Benzylic Ring-Opening of Aziridines
作者:Kangnan Li、Alexandria E. Weber、Luke Tseng、Steven J. Malcolmson
DOI:10.1021/acs.orglett.7b01886
日期:2017.8.18
Herein, we demonstrate a stereocontrolled synthesis of 1,3-diamines, which bear up to three contiguous stereogenic centers, through benzylic ring-opening of aziridines with 2-azaallyl anion nucleophiles. Reactions proceed efficiently (yield up to 95%), diastereoselectively (dr up to >20:1), site selectively, and enantiospecifically to deliver products with differentiated amino groups.