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Nonracemizable isocyanoacetates for multicomponent reactions.

Alexander G Zhdanko¹, Valentine G Nenajdenko

¹Department of Chemistry, Moscow State University, Moscow, Russia.

The Journal of Organic Chemistry

|December 23, 2008

Summary

New chiral ortho esters of alpha-isocyano acids prevent racemization during Ugi reactions. This method preserves the configuration of C-terminal amino acids in synthesized dipeptides.

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Area of Science:

Organic Chemistry
Synthetic Chemistry
Medicinal Chemistry

Background:

Alpha-isocyano acid esters are prone to racemization during multicomponent reactions.
Maintaining stereochemical integrity is crucial for synthesizing biologically active peptides.

Purpose of the Study:

To synthesize novel chiral ortho esters of alpha-isocyano acids.
To evaluate their stability against racemization in the Ugi four-component reaction (Ugi 4CC).
To develop a method for synthesizing dipeptides with preserved stereochemistry.

Main Methods:

Synthesis of chiral ortho esters from Cbz-protected alpha-amino acids.
Application of these ortho esters in the Ugi 4CC.
Deprotection of the resulting products to yield dipeptides.

Main Results:

Successfully synthesized chiral ortho esters of alpha-isocyano acids.
Demonstrated superior stability against racemization compared to known alpha-isocyano acid esters in Ugi 4CC.
Obtained dipeptides with preserved configuration at the C-terminal amino acid.

Conclusions:

Chiral ortho esters of alpha-isocyano acids are effective building blocks for stereoselective Ugi 4CC.
This approach provides a reliable route to enantiomerically pure dipeptides.
The developed method overcomes limitations of previous ester derivatives in peptide synthesis.