Studies on the role of tetrazole in the activation of phosphoramidites.
The mechanism of the tetrazole-activated coupling step in the synthesis of oligonucleotides via phosphoramidites is studied with the help of model reactions: Treatment of diethoxydiisopropylaminophosphane with two equivalents of tetrazole resulted in a diethoxy-tetrazolophosphane, whose (31P)-NMR shift of 126 ppm is identical with the signal observed during internucleotide bond formation. A series of different related diethoxy-phosphorous-acid derivatives were also synthesized; their (31P)-NMR signals between 123.9 and 130.8 ppm are additional evidence for the intermediacy of a tetrazolide species. Further NMR investigations with more basic azoles showed that tetrazole is also active as a proton donor.
Berner
S
S
Universität Ulm, Sektion Polymere, FRG.
Mühlegger
K
K
Seliger
H
H
D000577:Amides; D001393:Azoles; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009841:Oligonucleotides / Q000138:chemical synthesis*; D009943:Organophosphorus Compounds / Q000138:chemical synthesis; D010756:Phosphoric Acids; D013329:Structure-Activity Relationship; D013777:Tetrazoles
D000577:Amides; D001393:Azoles; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D010756:Phosphoric Acids; D013777:Tetrazoles; C045574:1H-tetrazole; C011067:phosphoramidic acid