“…Extending Nifant'ev's work on the synthesis of phosphinates through a radical chain mechanism, Piettre and co-workers found that substrates 213 − 215 react with hypophosphorous acid, H 2 P(O)OH, and its sodium salt, H 2 P(O)ONa, in the presence of a catalytic amount of tert -butylperoxypivalate as radical initiator to give the expected adducts 216 − 218 in 75−83% isolated yields (Chart ). , The α,α-difluoro- H -phosphinates thus obtained exhibit the features of typical hydrophosphoryl compounds and can participate in a second radical addition reaction. Thus, the sodium salt of hypophosphorous acid was shown to act as a double radical precursor in a double, sequential radical addition on 3- exo -methylenefuranose derivatives.…”
Section: 6 Radical Approachesmentioning
confidence: 98%
“…The reactions tolerate such functional groups as esters and amides. Probably the best example is the preparation of 4-(phosphonodifluoromethyl)- d , l -phenylalanines 75 , hydrolytically stable analogues of O -phosphotyrosine (Scheme ). , Other examples can be found describing syntheses of functionalized α,α-difluoromethylenephosphonates, which can serve as useful synthetic blocks for the preparation of peptides containing non-hydrolyzable analogues of phosphotyrosyl residues. ,− 27 …”
Section: 32 G
Em-difluorination Reactionsmentioning
confidence: 99%
“…For instance, when difluoroalkene 219 was reacted with hypophosphorous acid sodium salt in the presence of triethylborane and air, adduct 220 was isolated as a single diastereomer. Treatment of 220 with chlorotrimethylsilane in the presence of pyridine afforded O , O -bissilylated phosphite 221 , which upon reaction with oxygen and sulfur gave the corresponding phosphonate 222a and phosphonothioate 222b in the form of their disodium salts (Scheme ). , 7 65 …”
Section: 6 Radical Approachesmentioning
confidence: 99%
“…A discussion of the findings on α-monofluoroalkylphosphonates has been presented by Berkowitz and Bose . The chemistry of selected analogues of nucleotides and oligonucleotides featuring difluoromethylenephosphonate and difluoromethylenethiophosphonate groups was discussed by Piettre et al Synthesis of fluorine-containing bioisosters corresponding to phosphoamino acids and dipeptide units was reviewed by Otaka et al Some of the fluorine-containing phosphonates are discussed in books by Kukhar and Hudson 3 and Savignac and Iorga . Fluorinated phosphonates have also received some comments within reviews with wider scope. , 1 Naturally Occurring Phosphates ( A ) and Their Fluorinated Phosphonate Analogues ( B − D ) …”
“…Extending Nifant'ev's work on the synthesis of phosphinates through a radical chain mechanism, Piettre and co-workers found that substrates 213 − 215 react with hypophosphorous acid, H 2 P(O)OH, and its sodium salt, H 2 P(O)ONa, in the presence of a catalytic amount of tert -butylperoxypivalate as radical initiator to give the expected adducts 216 − 218 in 75−83% isolated yields (Chart ). , The α,α-difluoro- H -phosphinates thus obtained exhibit the features of typical hydrophosphoryl compounds and can participate in a second radical addition reaction. Thus, the sodium salt of hypophosphorous acid was shown to act as a double radical precursor in a double, sequential radical addition on 3- exo -methylenefuranose derivatives.…”
Section: 6 Radical Approachesmentioning
confidence: 98%
“…The reactions tolerate such functional groups as esters and amides. Probably the best example is the preparation of 4-(phosphonodifluoromethyl)- d , l -phenylalanines 75 , hydrolytically stable analogues of O -phosphotyrosine (Scheme ). , Other examples can be found describing syntheses of functionalized α,α-difluoromethylenephosphonates, which can serve as useful synthetic blocks for the preparation of peptides containing non-hydrolyzable analogues of phosphotyrosyl residues. ,− 27 …”
Section: 32 G
Em-difluorination Reactionsmentioning
confidence: 99%
“…For instance, when difluoroalkene 219 was reacted with hypophosphorous acid sodium salt in the presence of triethylborane and air, adduct 220 was isolated as a single diastereomer. Treatment of 220 with chlorotrimethylsilane in the presence of pyridine afforded O , O -bissilylated phosphite 221 , which upon reaction with oxygen and sulfur gave the corresponding phosphonate 222a and phosphonothioate 222b in the form of their disodium salts (Scheme ). , 7 65 …”
Section: 6 Radical Approachesmentioning
confidence: 99%
“…A discussion of the findings on α-monofluoroalkylphosphonates has been presented by Berkowitz and Bose . The chemistry of selected analogues of nucleotides and oligonucleotides featuring difluoromethylenephosphonate and difluoromethylenethiophosphonate groups was discussed by Piettre et al Synthesis of fluorine-containing bioisosters corresponding to phosphoamino acids and dipeptide units was reviewed by Otaka et al Some of the fluorine-containing phosphonates are discussed in books by Kukhar and Hudson 3 and Savignac and Iorga . Fluorinated phosphonates have also received some comments within reviews with wider scope. , 1 Naturally Occurring Phosphates ( A ) and Their Fluorinated Phosphonate Analogues ( B − D ) …”
“…6,7 During recent decades numerous fundamental researches were made on design and tactical application of phosphate and pyrophosphate isosteres. [8][9][10][11][12][13][14][15][16][17][18][19][20] The present review focuses on synthetic repertoires available for the construction of nucleoside polyphosphate analogues incorporating P-CXY-P scaffold. It is a continuation of previous communications from the authors' group that summarized advances in the synthesis of phosphonate-based bioisosteres.…”
This article provides an overview of the efforts toward the synthesis of nucleoside polyphosphate mimics featuring a P-CXY-P scaffold. The following synthetic approaches to these compounds are summarized: (i) nucleophilic displacement of 5´-O-tosyl nucleoside by the ammonium salts of methylenebisphosphonic acid; (ii) synthesis via activated phosphate/phosphonate substrates; (iii) Mitsunobu coupling between a nucleoside and methylenebisphosphonic acid; (iv) phosphorylation of a protected nucleoside under Yoshikawa's reaction conditions with methylenebis(phosphonic dichloride); (v) synthesis via nucleophilic cleavage of cyclic trimetaphosph(on)ates; (vi) enzyme-mediated reactions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
