ChemInform Abstract: 3‐ACYL‐1,3,2‐OXAZAPHOSPHOLANE UND PHOSPHORINANE. SYNTH. UND EINIGE EIGENSCHAFTEN

Abstract

Das Triamid (IV) reagiert mit den N‐Hydroxyalkylacetamiden (III) und (V) zu dem Oxazaphospholan‐ (II) bzw. Oxazaphosphorinanderivat (VI).

Deoxyribonucleoside Cyclic N-Acylphosphoramidites as a New Class of Monomers for the Stereocontrolled Synthesis of Oligothymidylyl- and Oligodeoxycytidylyl- Phosphorothioates

“…For example, cyclo-deesterification of the amidated benzyl thiophosphate protecting group may follow path a (Figure ) with the simultaneous formation of an oxazoline derivative. It has been reported that heating a 2-acetamidoethyl phosphite triester at 140−145 °C under vacuum leads to formation of 2-methyl-2-oxazoline . It could therefore be argued that a cyclo-deesterification reaction could also occur when the leaving group is a thiophosphate instead of an H -phosphonate diester derivative.…”

Amides of Trivalent Phosphorus Acids as Phosphorylating Reagents for Proton-Donating Nucleophiles

“…Phosphorylation of alkanols and phenols with ATPA is a general process used to prepare esters (or amido esters) of phosphorous acid and other acids of trivalent phosphorus. Initially, this reaction has been used for the synthesis of simple derivatives of the above-mentioned classes of compounds and has been recognized as being not only convenient but also practically feasible 101 for the preparation, in particular, of sterically hindered phenols. , Later, the phosphamide method has been widely used to synthesize various functionalized systems, whose molecules contain a trivalent phosphorus atom and other functional groups, e.g., phosphorylated amino − and amido − alcohols, choline, , partially acetalized triols, − quinine, fagaronin, biotin, − borneol, structural analogues of porphyrins, and halogenated alcohols. − …”

“…Considerable attention has been paid to the transamidation of phosphorus diamides in which one nitrogen atom carries an acyl group. These phosphamides were shown to exhibit low reactivity; the exchange involves the nonfunctionalized amide group, for example, see Scheme 91 …”

“…Initially, this reaction has been used for the synthesis of simple derivatives of the above-mentioned classes of compounds and has been recognized as being not only convenient but also practically feasible 101 for the preparation, in particular, of sterically hindered phenols. 162,163 Later, the phosphamide method has been widely used to synthesize various functionalized systems, whose molecules contain a trivalent phosphorus atom and other functional groups, e.g., phosphorylated amino [163][164][165][166][167][168] and amido [169][170][171][172][173][174] alcohols, choline, 175,176 partially acetalizedtriols, [177][178][179][180][181] quinine, 182 fagaronin, 183 biotin, [184][185][186] borneol, 164 structural analogues of porphyrins, 187 and halogenated alcohols. [188][189][190] Phosphorylation of functionalized alcohols can be accompanied by additional reactions; this extends the potentialities of classical synthesis and opens up simple routes to interesting heterocycles, for example, Scheme 27.…”

“…In recent years, systematic studies have been on the use of ATPA in the synthesis of sphingophospholipids, 285 which present great interest biologically. 312 Several research groups have shown that these compounds can be efficiently synthesized by phosphorylation of D-erythro-2-aminoalkane-1,3-diols with protected amino and secondary hydroxy groups by β-cyanoethyl-N,N-bis(diisopropyl)phosphorus diamide 170,[313][314][315][316] or bis(β-cyanoethyl) N,N-diisopropylphosphorus amide (31). 315,317,318 Oxidation of the resulting products and removal of the protecting groups gives rise to terminal phospholipids belonging to the class of primary phosphates.…”