Firdous Farooqui

Fast cleavage and deprotection of oligonucleotides

Abstract We have developed methylamine/ammonia as a fast cleavage and deprotection reagent which effects complete cleavage of oligonucleotides from the solid support in 5 min at room temperature and complete deprotection in 5 min at 65°C. The problem of transamination side product formation, faced with the commonly used dCbz (10.0% side product) upon treatment with methylamine/ammonia, has been successfully solved by the use of dCac (0.0% side product). DMT dCac phosphoramidite --methylamine/ammonia system furnished oligonucleotides in equal or superior quality as compared to the other systems.

Ultrafast Cleavage and Deprotection of Oligonucleotides Synthesis and Use of CAc Derivatives

Abstract We have investigated the use of alkylamines as fast cleavage and deprotection reagents for the solid phase synthesis of oligonucleotides and found methylamine/ammonium hydroxide (or methylamine) as an efficient reagent. The transamination side product formed with the commonly used dCbz has been eliminated by the use of dCAc phosphoramidite. This system has successfully been used in the synthesis of oligonucleotides and oligonucleoside phosphorothioates. DMT dCAc hydrogen phosphonate and DMT ribo CAc-2′-O Me phosphoramidite also have been prepared and used in the synthesis of oligonucleotides.

Elimination of transamination side product by the use of dCAc methylphosphonamidite in the synthesis of oligonucleoside methylphosphonates

Abstract The transamination side product formed by the use of dC bz or dC ibu methylphosphonamidite upon treatment with ethylenediamine has been eliminated by the use of dC Ac methylphosphonamidite. The synthesis and characterization of DMT dC Ac methylphosphonamidite is described.