- Biocatalytic Promiscuity of Lipases in Carbon-Phosphorus Bond Formation
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A promiscuous lipase-catalyzed carbon-phosphorus bond formation is presented. The developed enzymatic Pudovik-Abramov reaction of various aromatic and aliphatic aldehydes with dialkyl phosphonates provides biologically and pharmacologically relevant α-hyd
- Koszelewski, Dominik,Ostaszewski, Ryszard
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p. 2554 - 2558
(2019/04/30)
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- α-ketophosphonates as ester surrogates: Isothiourea-catalyzed asymmetric diester and lactone synthesis
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Isothiourea HBTM-2.1 catalyzes the asymmetric Michael addition/ lactonization of aryl- and alkenylacetic acids using α-keto-β, γ-unsaturated phosphonates as α,β-unsaturated ester surrogates, giving access to a diverse range of stereodefined lactones or enantioenriched functionalized diesters upon ring-opening.
- Smith, Siobhan R.,Leckie, Stuart M.,Holmes, Reuben,Douglas, James,Fallan, Charlene,Shapland, Peter,Pryde, David,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 2506 - 2509
(2014/05/20)
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- Enantioselective NHC-catalysed formal [4+2] cycloaddition of alkylaryl-ketenes with β,γ-unsaturated α-ketophosphonates
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NHC-mediated enantioselective formal [4+2] cycloadditions of alkylarylketenes with γ-substituted-β,γ-unsaturated α-ketophosphonates is described. A substrate-dependent switch in diastereoselectivity was observed, with γ-aryl α-ketophosphonates providing p
- Leckie, Stuart M.,Fallan, Charlene,Taylor, James E.,Brown, T. Bruce,Pryde, David,Lébl, Tomá?,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 1243 - 1249
(2013/07/25)
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- Mechanistic approach for expeditious and solvent-free synthesis of α-hydroxy phosphonates using potassium phosphate as catalyst
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An extremely simple, high yielding, highly rapid and solvent-free protocol has been described for hydrophosphylation of aldehydes using potassium phosphate as catalyst. Easy commercial availability of the reusable catalyst, operational simplicity at ambie
- Kulkarni, Makarand A.,Lad, Uday P.,Desai, Uday V.,Mitragotri, Satish D.,Wadgaonkar, Prakash P.
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p. 148 - 152
(2013/04/24)
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- Synthesis, characterization and catalytic properties of magnetic nanoparticle supported guanidine in base catalyzed synthesis of α-hydroxyphosphonates and α-acetoxyphosphonates
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Magnetic nanoparticle Fe3O4-immobilized guanidine (MNPs-Guanidine) as a novel magnetically interphase nanocatalyst was synthesized and characterized. MNPs-Guanidine catalyzed the synthesis of α-hydroxyphosphonates from aldehydes and
- Rostami, Amin,Atashkar, Bahareh,Moradi, Darush
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- Superparamagnetic magnesium ferrite nanoparticles: A magnetically reusable and clean heterogeneous catalyst
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A highly efficient magnetically recoverable nano-catalyst was fabricated. The material synthesized has been fully characterized by vibrating sample magnetometry (VSM), X-ray powder diffraction, scanning and transmission electron microscopy, FT-IR, and the
- Sheykhan, Mehdi,Mohammadnejad, Hossein,Akbari, Jafar,Heydari, Akbar
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experimental part
p. 2959 - 2964
(2012/07/30)
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- MgCl2/Et3N base system as a new catalyst for the synthesis of α-hydroxyphosphonate
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An efficient and simple synthesis of α-hydroxyphosphonates via reaction of aldehydes and ketones with dimethylphosphite in the presence of MgCl2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCl2/Et3N makes this method simple, convenient, and practical. Copyright
- Tajbakhsh, Mahmood,Khaksar, Samad,Tafazoli, Zahra,Bekhradnia, Ahmadreza
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experimental part
p. 827 - 829
(2012/05/21)
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- Enantioselective Friedel-Crafts alkylation reaction of indoles with α,β-unsaturated acyl phosphonates catalyzed by chiral phosphoric acid
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A variety of indoles underwent enantioselective Friedel-Crafts alkylation with α,β-unsaturated acyl phosphonates in the presence of 10 mol% chiral BINOL-based phosphoric acid and subsequent treatment with methanol and DBU to give methyl 3-(indol-3-yl)prop
- Bachu, Prabhakar,Akiyama, Takahiko
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supporting information; experimental part
p. 4112 - 4114
(2010/08/19)
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- Pyridine 2,6-dicarboxylic acid as a bifunctional organocatalyst for hydrophosphonylation of aldehydes and ketones in water
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A novel organocatalytic, direct synthesis of α-hydroxy phosphonates via reaction of aldehydes and ketones with trimethylphosphite in the presence of catalytic amounts of pyridine 2,6-dicarboxylic acid in water is reported. The method is simple, cost-effec
- Jahani, Fatemeh,Zamenian, Behi,Khaksar, Samad,Tajbakhsh, Mahmood
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experimental part
p. 3315 - 3318
(2010/11/18)
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- Amberlyst-15 as a heterogeneous reusable catalyst for the synthesis of α-hydroxy phosphonates in water
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An efficient and simple synthesis of α-hydroxy phosphonates has been achieved via reaction of aldehydes with trimethylphosphite in the presence of Amberlyst-15 in water. The reaction is highly selective with excellent yields under mild conditions. Georg T
- Tajbakhsh, Mahmood,Heydari, Akbar,Khalilzadeh, Mohammad A.,Lakouraj, Moslem M.,Zamenian, Behi,Khaksar, Samad
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p. 2347 - 2350
(2008/03/12)
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- Allylic hydroxy phosphonates: Versatile chiral building blocks
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Allylic hydroxy phosphonates are converted into β and γ substituted amino phosphonates using a series of palladium-catalyzed reactions. The judicious selection of nitrogen nucleophile and palladium catalyst allow for excellent regio- and stereochemical co
- De La Cruz, Antonette,He, Anyu,Thanavaro, Anchalee,Yan, Bingli,Spilling, Christopher D.,Rath, Nigam P.
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p. 2577 - 2592
(2007/10/03)
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- Stereospecific Pd(O)-Catalyzed Malonate Additions to Allylic Hydroxy Phosphonate Derivatives: A Formal Synthesis of (-)-Enterolactone
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A combination of cross-metathesis and malonate addition was applied to a formal synthesis of the mammalian lignan enterolactone 5. The cross-metathesis of alkene 6 and phosphonate 3a gave the substituted allylic phosphonate 3d. The palladium-catalyzed add
- Yan, Bingli,Spilling, Christopher D.
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p. 2859 - 2862
(2007/10/03)
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- Synthesis of nonracemic allylic hydroxy phosphonates via alkene cross metathesis
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Allylic hydroxy phosphonates and their derivatives can be interconverted by using cross metathesis with second generation Grubbs catalyst. The absolute stereochemistry of the starting phosphonate is conserved in the product. Cross metathesis reaction of t
- He, Anyu,Yan, Bingli,Thanavaro, Anchalee,Spilling, Christopher D.,Rath, Nigam P.
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p. 8643 - 8651
(2007/10/03)
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- Lithium perchlorate diethyl ether solution: A highly efficient media for the abramov reaction
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The α-hydroxy phosphonates are readily prepared by treating aromatic or aliphatic aldehydes and ketones with trialkylphosphite in the presence of trimethylsilylchloride in a very short time and in almost quantitative yields.
- Azizi, Najmedin,Saidi, Mohammad R.
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p. 1255 - 1259
(2007/10/03)
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- The synthesis of 1-hydroxy phosphonates of high enantiomeric excess using sequential asymmetric reactions: Titanium alkoxide-catalyzed P-C bond formation and kinetic resolution
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Titanium alkoxide-catalyzed asymmetric phosphonylation of aldehydes yields hydroxy phosphonates in moderate to good enantiomeric excess (e.e.s ~70%). The hydroxy phosphonates were acetylated and the acetates were subjected to enzyme-catalyzed kinetic resolution. The non-racemic acetates 2 (predominantly (R)-enantiomer) were hydrolyzed with an (R)-enantiomer-selective lipase, resulting predominantly in the hydrolysis of the (R)-isomer (at 85% conversion) to give the alcohols 3 with high e.e. Alternatively, hydrolysis of the minor enantiomeric (S)-acetate to approximately 20% conversion left the enriched (R)-configured acetate with improved e.e. (>90%). The moderate enantioselectivities obtained in the catalytic P-C bond formation are enhanced during the enzymatic hydrolysis. Furthermore, availability of the non-racemic phosphonates permits the use of less selective enzymes, resulting in higher yields in comparison with the standard resolution of racemic materials.
- Rowe, Bradley J.,Spilling, Christopher D.
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p. 1701 - 1708
(2007/10/03)
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- Enantioselective synthesis of dihydropyrans. Catalysis of hetero Diels - Alder reactions by bis(oxazoline) copper(II) complexes
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C2-symmetric bis(oxazoline) - Cu(II) complexes 1 and 2 catalyze the inverse electron demand hetero Diels - Alder reaction of α,β-unsaturated carbonyl compounds (heterodiene) with electron-rich olefins (heterodienophile) in high diastereo- and enantioselectivity, α,β- Unsaturated acyl phosphonates and β,γ-unsaturated α-keto esters and amides are effective heterodienes, while enol ethers and sulfides function as heterodienophiles. A range of substitution patterns is possible on the heterodiene: terminal alkyl, aryl, alkoxy, and thioether substituents are all tolerated. The enantioselective synthesis of dihydropyrans by this method has been shown to be straightforward: cycloadditions may be conducted with as little as 0.2 mol % of the chiral catalyst and are readily run on multigram scale. The reactions exhibit a favorable temperature - enantioselectivity profile, with selectivities exceeding 90% even at room temperature. A simple reaction protocol that employs a solid air-stable catalyst, convenient reaction temperatures, and low catalyst loadings is described. The utility of the derived cycloadducts in the preparation of chiral building blocks is demonstrated. Models for asymmetric induction are discussed considering product stereochemistry, X-ray crystallographic data for the solid catalysts, and mechanistic studies.
- Evans, David A.,Johnson, Jeffrey S.,Olhava, Edward J.
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p. 1635 - 1649
(2007/10/03)
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- Determination of the enantiomeric purity and absolute configuration of α-hydroxy phosphonates
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The absolute configuration of α-hydroxy phosphonates was determined by NMR spectroscopy of the O-methyl mandelate ester derivatives. The O-methyl mandelate ester diastereoisomers are distinguishable by their 1H and 31P NMR spectra an
- Kozlowski, James K.,Rath, Nigam P.,Spilling, Christopher D.
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p. 6385 - 6396
(2007/10/02)
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- The enantioselective addition of dialkylphosphites to aldehydes: Catalysis by a lanthanum binaphthoxide complex
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The enantioselective addition of dialkylphosphites to aldehydes was catalyzed by a lanthanum (R)-binaphthoxide complex to give (S)-hydroxy phosphonates in good yield and modest enantioselectivity
- Rath, Nigam P.,Spilling, Christopher D.
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p. 227 - 230
(2007/10/02)
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