posted on 2018-01-25, 00:00authored byYuyang Li, Ronald Kluger
Biochemical systems utilize adenylates
of amino acids to aminoacylate
the 3′-terminal diols of tRNAs. The reactive acyl group of
the biological acylation agent is a subset of the general class of
acyl phosphate monoesters. Those compounds are relatively stable in
aqueous solutions, and their alkyl esters are conveniently prepared.
It has previously been shown that biomimetic reactions of acyl phosphate
monoesters with diols and carbohydrates are promoted by lanthanide
salts. However, they also promote hydrolysis of acyl phosphate reagents,
and the overall yields are modest. An assessment of the catalytic
potential of alternative Lewis acids reveals that lead ions may be
more effective as catalysts than lanthanides. Treatment of carbohydrates
with benzoyl methyl phosphate (BMP) and triethylamine in water with
added lead nitrate produces monobenzoyl esters in up to 75% yield.
This provides a water-compatible pathway for novel patterns of benzoylation
of polyhydroxylic compounds.