A Novel Polymer Supported Approach to Nucleoside Modification
作者:Suyeal Bae、Mahesh K. Lakshman
DOI:10.1021/jo702558n
日期:2008.5.1
Polymer-supported O-6-(benzotriazol-1-yl)inosine derivatives (Pol-I and Pol-dI) have been synthesized reasonably effectively via reaction of nucleoside phosphonium salts with polymer-linked HOBt (Pol-HOBt). In constast to solution chemistry, use of polymer-supported BOP (Pol-BOP) did not lead to efficient nucleoside loading. Presence of the nucleosides on the support could be readily detected by MAS NMR. Exposure of the polymer-supported nucleosides, Pol-I and Pol-dI, to alcohol, phenol, thiol and amine nucleophiles caused cleavage from the support leading directly to the C-6 modified nucleoside analogues. To our knowledge, these are the first examples of the application of such technology for nucleoside modification. Where possible, results of reactions with the polymer-supported nucleosides are compared to those from solution chemistry, providing insight into the differences between the two techniques. These new polymer-supported nucleosides can be conveniently utilized for diversity-oriented synthesis.
Synthesis of N6,N6-Dialkyladenine Nucleosides Using Hexaalkylphosphorus Triamides Produced in Situ
作者:Mahesh K. Lakshman、Asad Choudhury、Suyeal Bae、Eliezer Rochttis、Padmanava Pradhan、Amit Kumar
DOI:10.1002/ejoc.200800752
日期:——
Reactions between secondary amines and phosphorus trichloride (PCl3) leads to the formation of the corresponding tris(dialkylamino)phosphines or hexaalkylphosphorus triamides [HAPT: (R2N)3P]. Reaction of silyl-protected 2'-deoxyinosine and acetyl-protected inosine with the in situ formed HAPT and iodine (I2) leads to the formation of N6,N6-dialkyl adenosine and 2'-deoxyadenosine. In some cases the