69874-73-3Relevant articles and documents
A practical aryl unit for azlactone dynamic kinetic resolution: Orthogonally protected products and a ligation-inspired coupling process
Tallon, Sean,Manoni, Francesco,Connon, Stephen J.
, p. 813 - 817 (2015/02/19)
The first strategy for bringing about enantioselective azlactone dynamic kinetic resolution to generate orthogonally protected amino acids has been developed. In the presence of a C2-symmetric squaramide-based catalyst, benzyl alcohol reacts with novel yet readily prepared tetrachloroisopropoxycarbonyl-substituted azlactones to generate trapped phthalimide products of significant synthetic interest with excellent enantiocontrol. These materials are masked amino acids which are demonstrably orthogonally protected: cleavage of the phthalimide can be achieved in the presence of the ester and vice versa. This process could be utilized to bring about a highly stereoselective ligation-type coupling of protected serines (at stoichiometric loadings) with racemic azlactones derived from both natural and abiotic amino acids. After deprotection, a subsequent base-mediated Oa??N acyl transfer occurs to form a dipeptide.
Biologically active halophthaloylpeptides. I - Synthesis of tetrachlorophthaloylamino acids and dipeptide derivatives
El-Naggar,Zaher,El-Basiouny,Khalaf
, p. 154 - 161 (2007/10/02)
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