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
<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
Abstract Herein we report a facilesynthesis of esters of bis‐α‐aminoalkylphosphinic acids obtained by an addition of Cbz‐protected phosphinic analogues of amino acid methyl esters to an appropriate imine in refluxing benzene. Complete deprotection of the esters could be achieved in one step by the action of 30% HBr in acetic acid.
Oxazoline-Based Organocatalyst for Enantioselective Strecker Reactions: A Protocol for the Synthesis of Levamisole
作者:Arghya Sadhukhan、Debashis Sahu、Bishwajit Ganguly、Noor-ul H. Khan、Rukhsana I. Kureshy、Sayed H. R. Abdi、E. Suresh、Hari C. Bajaj
DOI:10.1002/chem.201302007
日期:2013.10.11
catalyze asymmetric Streckerreactions of various aromatic and aliphatic N‐benzhydrylimines with trimethylsilylcyanide (TMSCN) as a cyanide source at −20 °C to give α‐aminonitriles in high yield (96 %) with excellent chiral induction (up to 98 % ee). DFT calculations have been performed to rationalize the enantioselective formation of the product with the organocatalyst in these reactions. The organocatalyst
Synthesis and biological evaluation of phosphino dipeptide isostere inhibitor of human β-secretase (BACE1)
作者:Florian Manzenrieder、Andreas O. Frank、Timo Huber、Cornelia Dorner-Ciossek、Horst Kessler
DOI:10.1016/j.bmc.2007.03.072
日期:2007.6
Phosphino dipeptide (PDP) isosteres are known to be useful analogues of the transition state of metalloprotease substrates. Here we describe the use of this unit for the design of aspartic protease inhibitors. A PDP analogue of OM00-3, a potent BACEl inhibitor, was synthesized and exhibited high biological activity (IC50 similar to 12 nM). (C) 2007 Elsevier Ltd. All rights reserved.