Some reactions of O,O-diphenylphosphoryl azide

Abstract

Diphenylphosphoryl azide, in contrast to N,N'-disubstituted phosphorodiamidic azides, undergoes nucleophilic displacement of the azido group by reaction with water, butanol, ammonia, and amines. Possible mechanisms for the conversion of diphenylphosphoryl azide into urethanes and amides are briefly discussed. Pyrolysis of N,N'-dicyclohexylphosphorodiamidic azide gave the phosphenimidic amide dimer. 0,O-Diphenylphosphoryl azide (1) has been obtained by reaction of the phosphorochloridate with sodium azide. This compound undergoes pseudohalogen replacement of the azido group by treatment with nucleophilic reagents, such as water, butanol, ammonia, and various amines. Thus with aniline, the corresponding N-phenylphosphoramidate (2; R = Ph) was formed in high yield:With strong bases, like ammonia and aliphatic amines, the reaction was rapid and exothermic at room temperature; but with weaker bases, like aniline, there was no apparent reaction at room temperature.The reactivity of the azide (1) towards nucleophiles resembled the behaviour of sulphonyl azides,' but differed markedly from that of N,Nf-disubstituted phosphorodiamidic azides which were very stable towards nucleophilic substitution at phosp h o r~~.~ However, efforts to obtain a phosphoryl nitrene insertion reaction, by heating the azide (1) with boiling o-xylene under similar conditions to those successfully used for the analogous reaction with sulphonyl azides,' were unsuccessful.The stability of the azide (1) towards heating was shown by its distillation at 157OY3 and by the fact that vigorous evolution of nitrogen was not observed until a temperature of 175" had been reached.

Partially Modified Retro-Inverso Peptides: Development, Synthesis, and Conformational Behavior

“…97,98 Reaction of DPPA with an N-protected R-amino acid Scheme 1. Rearrangements Leading to gem-Diamino Derivatives a (e.g., 17) or peptide yields the corresponding acyl azide.…”

“…The other popular method for the synthesis of α-aminoacyl azides en route to PMRI peptides uses the reagent diphenylphosphoryl azide (DPPA). , Reaction of DPPA with an N -protected α-amino acid (e.g., 17 ) or peptide yields the corresponding acyl azide. Under the usual reaction conditions the acyl azide undergoes the Curtius rearrangement to yield the corresponding isocyanate (e.g., 18 ), which is trapped with an appropriate alcohol (either in situ or added subsequently) to furnish the desired gem -diaminoalkyl derivative (e.g., 19 ) (Scheme ). ,,

4 An Example of the Use of DPPA for the Synthesis of the Protected g em -Diaminoalkyl Derivative Z- g Glp-Z, 19 66,99

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Diphenylphosphoryl‐Triazole‐Tethered, AIEE‐Type Conjugated Polymer as Optical Probe for Silver Ion in Relatively High‐Water‐Fraction Medium

“…These findings indicate the appreciable consumption of CH group in the following click postpolymerization. There are also other three distinctive absorption bands that appear exclusively in the spectrum of P3 , with the location at ≈ 1285, ≈ 1101, and 955 cm −1 , respectively, which can be assigned to the stretching vibration of PO (≈1285 cm −1 ) and PO (≈ 1101 and 955 cm −1 ) segments in the tethered DPPT groups of P3 . Given the same backbone and other alkyl attachments, 1 H NMR spectra of these three polymers resemble to each other on the whole (Figure S2, Supporting Information).…”

Nanomolar E-Selectin Antagonists with Prolonged Half-Lives by a Fragment-Based Approach

“…The C-alkylated 5-nitroindole 32a was obtained via a Vilsmeier formylation of 4 29 (→ 30), followed by reduction to alcohol 31, which was directly converted to azide 32a using diphenylphosphoryl azide (DPPA). 30 The syntheses of the nitroindoles with 3-azidoethyl (→ 32b), 3-azidopropyl (→ 32c), and 3-azidobutyl (→ 32d) linkers via a Larock indole synthesis 31 have been previously reported. 16 In situ Click Experiments.…”