Presentation Title

Diastereoselective Synthesis of Unnatural Amino Acids Using Imine Electrophiles

Faculty Mentor

Jeff Scott Cannon

Start Date

23-11-2019 8:00 AM

End Date

23-11-2019 8:45 AM

Location

239

Session

poster 1

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

Amino acids are basic building blocks of life on Earth that are essential in both chemical and biological syntheses. Twenty amino acids exist in enantiopuric form by nature. Yet, unnatural amino acids are difficult to access in such form. Thus, new methods for stereoselective synthesis of unnatural amino acids are of high interest. A general methodology for the generation of sulfinamido-ester enolates has been developed for enantioselective synthesis of glycine derivatives. First, Ellman's auxiliary, a chiral tert–butalsulfinamide, is synthesized in high yields via two–step process. The auxiliary alkylates by forming an enolate with the base NaHMDS at –78 °C followed by treatment with benzaldehyde, an electrophile, to generate a new carbon–carbon bond and lead to formation of two stereocenters. Our goal is to control the diastereoselectivity at this new arrangement step by altering reaction conditions and adding different metal additives. Our results have achieved diastereoselective control but yields remain low. We are working to optimize our reaction conditions to improve our yields. Once successful, this enolate chemistry has great potential to be applied to useful pharmaceutical purposes, synthetic methods, and total syntheses.

This document is currently not available here.

Share

COinS
 
Nov 23rd, 8:00 AM Nov 23rd, 8:45 AM

Diastereoselective Synthesis of Unnatural Amino Acids Using Imine Electrophiles

239

Amino acids are basic building blocks of life on Earth that are essential in both chemical and biological syntheses. Twenty amino acids exist in enantiopuric form by nature. Yet, unnatural amino acids are difficult to access in such form. Thus, new methods for stereoselective synthesis of unnatural amino acids are of high interest. A general methodology for the generation of sulfinamido-ester enolates has been developed for enantioselective synthesis of glycine derivatives. First, Ellman's auxiliary, a chiral tert–butalsulfinamide, is synthesized in high yields via two–step process. The auxiliary alkylates by forming an enolate with the base NaHMDS at –78 °C followed by treatment with benzaldehyde, an electrophile, to generate a new carbon–carbon bond and lead to formation of two stereocenters. Our goal is to control the diastereoselectivity at this new arrangement step by altering reaction conditions and adding different metal additives. Our results have achieved diastereoselective control but yields remain low. We are working to optimize our reaction conditions to improve our yields. Once successful, this enolate chemistry has great potential to be applied to useful pharmaceutical purposes, synthetic methods, and total syntheses.