Benzotriazol-l-yloxy tris

The derivative 90 was obtained by condensation of the purpurin-18-A-hexylimide-17-propionic acid with aminolactose heptaacetate in the presence of benzotriazol-l-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) followed by the deacetylation procedure. The lactose-photosensitiser conjugate linked by an ethylene moiety was also prepared by following a similar approach. The purpurin-18-methyl ester 81 was converted into /V-(3-iodobenzyl)/ /evo-purpurin-18-7V-hexylimide-17-propionic ester by hydrogenation over Pd/C followed by reaction with 3-iodo-benzylamine. Afterwards, the propargyllactose heptaacetate reacted with A-(3-iodobenzyl)rMeio-purpurin-18-A-hexylimide-l 7-propionic ester in the presence of tris(dibenzylidieneacetone)dipalladium(0) (Pd2-dba3) which, after deacetylation conditions, afforded the derivative 89 (Fig. 9).68... 

Recently, an interesting method involving an intramolecularly assisted dchydrolluorination, mediated by (benzotriazol-l-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), was described.37 The reaction proceeds via a hydrobenzotriazole ester intermediate followed by concerted intramolecular elimination of hydrogen fluoride. 

Abbreviations BOP, benzotriazol-l-yloxy-tris(dunethylamino)phosphonium hexafluoro-phosphate DCC, N.N -dicyclohexylcarbodiimide DIC, /V./V -diisopropylcarbodiimide DME, dimethoxyethane DMF, /V./V-dimethyl form amide DIEA, /V-cthyldiisopropyla-mine Et20, diethyl ether HOBt, 1-hydroxybenzotriazole HOSu, iV-hydroxysuccimmide t-BuOMe, tert-butylmethylether TFA, trifluoroacetic acid TIS, triisopropylsilane. 

BOP benzotriazol-l-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate... 

A 20-mL scintillation vial containing a stirrer bar was charged with the product from Step 2 (0.05 mmol) dissolved in 2 ml THF, triethylamine (0.1 mmol), phenylacetic acid (0.05 mmol), and 50p>ml IM benzotriazol-l-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate dissolved in N,N-dimethylformamide. The vial was capped, stirred 1 hour at ambient temperature, 4 ml of diethyl ether and 2 ml water added, and the aqueous layer withdrawn. This procedure was repeated with 2 ml saturated NaHC03 and NaCl solutions. Thereafter, the solution was dried, transferred to a pre-weighed scintillation vial, rinsed with 2 ml chloroform, the material concentrated, and the product isolated. 

Benzotriazole-l-yloxy-tris(dimethylamino)-phosphonium hexafluorophosphate (BOP). 

The resin was then treated with the active ester of N-Fmoc-L-F2Pmp-OH (6), which was prepared in a separate vessel by stirring a mixture of 103 mg (0.20 mmol) N-Fmoc-L-F2Pmp-OH, 28 mg (0.20 mmol) HOBt, 88 mg (0.20 mmol) benzotriazole-l-yloxy-tris(dimethylamino)-phosphonium hexafluorophosphate (BOP), 70 pL (0.40 mmol) diisopropylethylamine (DIPEA) in 1 mL NMP at room temperature for 10 min prior to transferring to the resin. 

BOP = (benzotriazol-l-yloxy)tris(dimethylamino)phosphonium hexalluorophosphate BSA = A,0-bis(trimethylsilyl)acetamide [MeC(OSiMe3)=NSrMe3]... 

Several reports have dealt with the use of phosphinic pseudodipeptide building blocks in peptide couplings where both phosphinic and carboxylic acids are unprotected. Among the coupling reagents used successfully for such transformations are W,W -carbonyldiimidazole (CDl) [66-68], (benzotriazol-l-yloxy)tris (dimethylamino)phosphonium hexafluorophosphate (BOP) [69, 70],... 

The phosphonium salts are important reagents in organic synthesis, which include PyBroP Bromotri(pyrrolidino)phosphonium hexafluorophosphate], BroP [Bromotris(dimethylamino)phosphonium hexafluorophosphate], PyBOP [(Benzotriazol-l-yloxy)tripyrrolidinophosphonium hexafluorophosphate], and BOP [(Benzotriazol-l-yloxy)tris(dimethylamino)phos-phonium hexafluorophosphate]. 

Couple the second residue by 2 Eq of (benzotriazol-l-yloxy)tris(dimethylamino) phosphonium hexafluorophosphate (BOP) and diisopropylethylamine in dimethylformamide for 2 h. 

Abbreviations CDMT = 2-chloro-4,6-dimethoxy-l,3,5-triazine EDCI = l-ethyl-3-(3-dimethyla-minopropyl)carbodiimide BOP = benzotriazol-l-yloxy-tris-(dimethylamino)phosphonium hexa-fluorophosphate DIPEA = diisopropylethylamine DEPC = diethylphosphoryl cyanide CBM IT = l,l-carbonylbis(3-methylimidazolium triflate HOBt = 1-hydroxybenzotriazole hydrate HBPyU = 0-(benzotriazole-l-yl)-iV,Af,A,Af-bis(tetramethylene)uronium hexafluorophosphate. 

BOP (l,2,3-benzotriazol-l-yloxy)-tris(dimethylamino)phosphoniumhexaflurophos-phate... 

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