4-Nitrophenyl phenyl phosphorochloridate: a new phosphorylating agent for oligonucleotide synthesis

Abstract

2′,5′-Protected ribonucleosides (7) and 5′-protected 2′-deoxyribonucleosides (8) readily react with 4-nitrophenyl phenyl phosphorochloridate (1a) in the presence of base to give good to high yields of phosphotriesters of general formula (2a) which, on treatment with p-thiocresol and triethylamine in acetonitrile are quantitatively converted into the corresponding phosphodiesters (3a); the latter are intermediates in oligonucleotide synthesis by the phosphotriester approach.