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Lithium-Salt Effects in Peptide Synthesis. Part I. Conditions for the Use of Lithium-Salts in Coupling Reactions

✍ Scribed by Adrian Thaler; Dieter Seebach; Francis Cardinaux

Publisher: John Wiley and Sons
Year: 1991
Tongue: German
Weight: 679 KB
Volume: 74
Category: Article
ISSN: 0018-019X
DOI: 10.1002/hlca.19910740319

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The influence of Li‐salts on the course of peptide‐coupling reactions was investigated. As a model for segment couplings, Ac‐Phe‐OH was coupled to HCl·H‐Ala‐OMe using the mixed anhydride, DCC1, DCCl/HOBt, BOP‐Castro and TBTU‐Knorr methods. As a model for stepwise synthesis Z‐Phe‐OH was coupled with HCl·Ala‐O(t‐Bu), using symmetrical anhydrides and active esters. The effects of salt additives such as LiCl, LiBr, LiC10~4~, and ZnCl~2~ on yields, side‐product formation, racemisation, and reaction rates are reported.

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