A8 an alternative to the use of dibenzyl and di-&-butyl phosphorohalidates for the phosphorylation of alcohols.1-3 our reoent studies have ooncentrated on the use of dialkyl &&diethylphosphoramidites for the efficient phosphorylation OP alcohols and hydroxycontaining biomoleoules. In particular, we have concentrated on the use of benxyl and k-butyl groups for temporary phosphate proteotion on aoaount of the facile hydrogenolytia' or aoidolytic' cleavage of these phosphate protecting groups. From these studies, we have demonstrated that the phosphoramidite reagents, di-k-butyl &~-diethylphosphoramidite & and dibensyl b&diethylphosphoramidite &J, are stable yet highly reactive reagents for the 'phosphite-triester' phosphorylation of simple alkyl alcohols Ifi) (R0j2PNEt2 (R = But or Bzl)/lH-tetrazole, (ii) mCPBA1 and give the respeotive di-k-butyl and dibenxyl phosphorotriesters in 9U-99% yields (Scheme 1).4*5 In this letter, we report the use of 8aheme 1.
B 'OH m),Prst, -1 1 ePEA a P'O-P /OR .OE -a'o-P(oIl) -4dD 2 Fl@d/", 0 lE-tetrazole a+ E'o-P(oE)~ & and & for the efficient 'phosphite-triester' phosphorylation of a proteated serine tyrosine derivative, a protected serine-aontaining peptide and a resin-bound proteoted serine-oontaining peptide.