Dibenzyl diisopropylphosphoroamidite

Example 15 in connection with studies on thermal stability of proteins and nucleic acids of the methanogen species the cyclodiphospho-D-glycerate (CDPG) has been synthesized by Priestley from n-butyl-D-glycerate employing dibenzyl diisopropylphosphoroamidite (BnO)2PNiPr2 reagent [43]. 

Example 12 dibenzyl-iV,iSr-diisopropylphosphoroamidite has been applied by Lindberg et al. in the efficient synthesis of phospholipids from glycidol phosphates [39]. 

Example 16 the synthesis of (-)-shikimate-3-phosphate by Shin and Wu [44] using dibenzyl-iV,N-diisopropylphosphoroamidite and subsequent oxidation by CPBA (steps a and b) involves the deprotection of the final triester phosphate by trimethylbromosilane (TMBS) which allows simultaneous removal of benzyl 2,2,3,3-tetramethoxybutane and methyl groups (steps c and d). 

The coupling led to the intermediate phosphite (step a) which was oxidized by TBHP (step b). The phosphate formed containing eight ethoxy groups was deprotected by trans-esterification using trimethylbromosilane and subsequent hydrolysis by water (step c). Two benzoyl groups were removed by basic hydrolysis (step d). The same tetrakis phosphate was prepared by phosphitylation with dibenzyl-h/,iSr-diisopropylphosphoroamidite in the presence of tetrazole (step c) followed by oxidation with CPBA (step f). The removal of all benzyl and benzoyl groups was achieved in one step by sodium in liquid ammonia (step g). 

---