Increased efficiency in biomimetic Lewis acid–base pair catalyzed monoacylation of diols by acyl phosphate monoesters

Yuyang Li,Ronald Kluger,Maxim V Berezovski

doi:10.1139/facets-2017-0047

Abstract

Acyl phosphate monoesters are biomimetic acylation reagents that require coordination to metal ions to react with cis-diol substrates in water. With lanthanide catalysts, outcomes are compromised by (1) the competitive lanthanide-promoted hydrolysis of the acyl phosphate reagents as well as by (2) the high affinity of lanthanum ions for the phosphate monoester by-product. Based on analysis of the mechanism of the process, optimizing reaction conditions can selectively inhibit the lanthanum-promoted hydrolysis of acyl phosphate monoesters. Furthermore, using zinc salts and lead salts in place of lanthanides enhances the reactivity of the reactants and causes less complexation of the metal ion with the by-products.

Highlights

The utility of acyl phosphates esters as biomimetic reagents for selective monoacylation of diols is a subject of continuing interest with important applications, including kinome interrogation (Patricelli et al 2007; Nordin et al 2015) and aminoacylation of the 3′-terminus of tRNA (Tzvetkova and Kluger 2007; Duffy and Dougherty 2010)
Utilizing acyl phosphate monoesters as metal-coordinated acyl donors at the same Lewis acid where the ionized diol is coordinated promotes the reaction without involvement of the solvent
We found that conducting reactions in mixtures of DMSO and water reduced the rate of hydrolysis of phenylalanyl ethyl phosphate (PheEtP) in the presence of lanthanum ion compared with the reaction in water alone

Summary

Introduction

The utility of acyl phosphates esters as biomimetic reagents for selective monoacylation of diols is a subject of continuing interest with important applications, including kinome interrogation (Patricelli et al 2007; Nordin et al 2015) and aminoacylation of the 3′-terminus of tRNA (Tzvetkova and Kluger 2007; Duffy and Dougherty 2010). Utilizing acyl phosphate monoesters as metal-coordinated acyl donors at the same Lewis acid where the ionized diol is coordinated promotes the reaction without involvement of the solvent. Complications arise from the competing effectiveness of the lanthanum ion in the hydrolysis of phosphate derivatives that are the acylation reagents (Hendry and Sargeson 1989; Kluger et al 1997). The effect of temperature on product yield was studied by conducting reactions at 20 and 4 °C.

Results

Conclusion