Propylphosphonic anhydride

Durette et al. [74] have achieved the total synthesis of the hexadepsipeptide antibiotic L-156,602 128) using the mixed phosphonic anhydride method as key macrolactamization step. As shown in Scheme 43, treatment of the linear depsipeptide 126 with n-propylphosphonic anhydride and DMAP in dichloro-methane at high dilution afforded the macrocycle 127 in more than 57% yield. 

PEPTIDES Bis(o-nitrophenyl)phenyl-phosphonate. Dicyclohexylcarbodi-imide. Diphenyl N-succinimidyl phosphate. N-Methyl-N-phenylbenzohydra-zonyl bromide. n-Propylphosphonic anhydride. Trifluoromethanesulfonic acid-Thioanisole. 

Example 5, Using propylphosphonic anhydride (T3P) as the coupling agent ... 

Chung and coworkers reported an efficient stereoselective synthesis of dual orexin receptor anatagonist MK-6096 (61) (Scheme 41) (14OL5890). The pyrimidine moiety was introduced via a Negishi coupling reaction of 2-chloropyrimidine with (2-cyano-4-methylphenyl)zinc(II) chloride. Subsequent hydrolysis with 12N HCl in acetonitrile furnished the required carboxylic acid, which was coupled with the hydrochloric acid salt of amino ether 62 via a 1-propylphosphonic-anhydride-catalyzed amidation. The overall yield of this synthesis was 37%. 

One of the Vertex s process routes involves the use of an interesting coupling agent propylphosphonic anhydride T3P, [Pr(P=0)0]3 to bridge the final amide bond. Therefore, commercially available 14 was transformed to carbonate 21, which was nitrated using nitric acid in concentrated sulfuric acid to give nitrobenzene 22. 

Propylphosphonic anhydride (44, T3P ) catalyses Beckmann rearrangements ketoximes give amides (84-95% yield) and aldoximes give nitriles (87-99%). ... 

Wen, X., Bakali, J. E., Deprez-Poulain, R. and Deprez, B. 2012. Efficient propylphosphonic anhydride ( T3P) mediated synthesis of benzothiazoles, benzoxazoles and benzimidazoles. Tetrahedron Lett. 53(19) 2440-2443. 

Imidazo[l,2-(j]pyridines can be prepared from a multicomponent reaction of alcohols, 2-aminopyridines, and isocyanides (Scheme 53) (13TL95). The alcohols are oxidized by DMSO and propylphosphonic anhydride, which also catalyzes the nucleophilic addition with isocyanides. Aromatic alcohols with electron-donating and electron-withdrawing groups can provide the desired... 

In a recent example of p-lactam formation dehydration ofphenoxyacetic acid with 2-fluoro-l-methylpyridinium p-toluenesulfbnate in the presence of diaryhmines is proposed to proceed thorough the pyridinium intermediate 142 which leads to phenoxyketene, which reacts by [2 + 2] cycloaddition with the imine forming the product ds-P-lactam (Eqn (4.87)). Similahly propylphosphonic anhydride (T3P) was also successful in carboxylic acid activation (Eqn (4.88)). 

Quinoline can be easily synthesised by using different catalyst in mild conditions. Augustine et al. [8] synthesised quinoline derivative with mild reagent T3P (Propylphosphonic anhydride). This protocol is free from side reaction, such as self-condensation of ketones. It has tolerance for both acid sensitive and base sensitive functional groups with good yield. 

J.K. Augustine, A. Bombrun, S. Venkatachaliah, An efficient catalytic method for the Friedlander annulation mediated by peptide coupling agent propylphosphonic anhydride (T3P) Tetrahedron. Lett. 52 (2011) 6814-6818. 

Esterification and amidation l-hydroxy-3-phospholene 1-oxides (735) have been realised in the presence of propylphosphonic anhydride (T3P ) (Scheme 205). ... 

An efficient method for the Beckmann rearrangement of ketoximes and aldoximes (659) to amides/lactams (661) and nitriles (662) catalysed by the cyclic n-propylphosphonic anhydride (660), has been described by Mandal et al. (Scheme 166). ... 

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