- Aryltrimethylammonium Tetrafluoroborates in Nickel-Catalyzed C–P Bond-Forming Reactions
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Abstract: The first nickel-catalyzed phosphorylation of aryltrimethylammonium tetrafluoroborates with the formation of C–P bond instead of C–N has been developed. Starting from easily available and inexpensive aromatic amines, a variety of important arylphosphonates have been synthesized in moderate to excellent yields.
- Li, Chun Jing
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p. 954 - 960
(2021/07/22)
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- Selective hydrolysis of phosphorus(v) compounds to form organophosphorus monoacids
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An azide and transition metal-free method for the synthesis of elusive phosphonic, phosphinic, and phosphoric monoacids has been developed. Inert pentavalent P(v)-compounds (phosphonate, phosphinate, and phosphate) are activated by triflate anhydride (Tf2O)/pyridine system to form a highly reactive phosphoryl pyridinium intermediate that undergoes nucleophilic substitution with H2O to selectively deprotect one alkoxy group and form organophosphorus monoacids.
- Ash, Jeffrey,Cordero, Paula,Huang, Hai,Kang, Jun Yong
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p. 6007 - 6014
(2021/07/21)
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- Controllable phosphorylation of thioesters: Selective synthesis of aryl and benzyl phosphoryl compounds
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The controllable phosphorylations of thioesters were developed. When the reaction was catalyzed by a palladium catalyst, aryl or alkenyl phosphoryl compounds were generated through decarbonylative coupling, while the benzyl phosphoryl compounds were produced through deoxygenative coupling when the reaction was carried out in the presence of only a base.
- Xu, Kaiqiang,Liu, Long,Li, Zhaohui,Huang, Tianzeng,Xiang, Kang,Chen, Tieqiao
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p. 14653 - 14663
(2020/12/29)
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- A case of chain propagation: α-aminoalkyl radicals as initiators for aryl radical chemistry
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The generation of aryl radicals from the corresponding halides by redox chemistry is generally considered a difficult task due to their highly negative reduction potentials. Here we demonstrate that α-aminoalkyl radicals can be used as both initiators and chain-carriers for the radical coupling of aryl halides with pyrrole derivatives, a transformation often employed to evaluate new highly reducing photocatalysts. This mode of reactivity obviates for the use of strong reducing species and was also competent in the formation of sp2 C-P bonds. Mechanistic studies have delineated some of the key features operating that trigger aryl radical generation and also propagate the chain process.
- Constantin, Timothée,Juliá, Fabio,Leonori, Daniele,Sheikh, Nadeem S.
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p. 12822 - 12828
(2020/12/29)
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- Nickel-Catalyzed Phosphorylation of Tosylates
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Abstract: Four new bidentate phosphine ligands have been synthesized, characterized and evaluated in Ni-catalyzed C–P coupling reaction. The readily available and inexpensive highly active sulfonate Ni(cod)2-L8 catalyzes the reaction leading to
- Li, Chun-jing
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p. 725 - 730
(2020/06/30)
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- Cobalt catalyzed C-P bond formation by cross-coupling of boronic acids with P(O)H compounds in presence of zinc
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In our current work, we have reported the first cobalt-catalyzed cross-coupling of arylboronic acid with alkyl/aryl phosphites under mild conditions. The reaction was carried out in the presence of zinc powder as an additive and ter-pyridine as a ligand. The use of non-precious cobalt salt makes the protocol advantageous, as it is inexpensive and more abundant than the previously used methods where precious metal salts (Pd and Pt) were used. The reaction has a wide substrate scope and the products were obtained in good yields.
- Hicks, Ian,McTague, Jonathan,Hapatsha, Tatiana,Teriak, Rania,Kaur, Parminder
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- Decarbonylative Phosphorylation of Carboxylic Acids via Redox-Neutral Palladium Catalysis
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We describe the direct synthesis of organophosphorus compounds from ubiquitous aryl and vinyl carboxylic acids via decarbonylative palladium catalysis. The catalytic system shows excellent scope and tolerates a wide range of functional groups (>50 examples). The utility of this powerful methodology is highlighted in the late-stage derivatization directly exploiting the presence of the prevalent carboxylic acid functional group. DFT studies provided insight into the origin of high bond activation selectivity and P(O)-H isomerization pathway.
- Liu, Chengwei,Ji, Chong-Lei,Zhou, Tongliang,Hong, Xin,Szostak, Michal
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supporting information
p. 9256 - 9261
(2019/11/19)
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- Avisible-light-promoted metal-free strategy towards arylphosphonates: Organic-dye-catalyzed phosphorylation of arylhydrazines with trialkylphosphites
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A visible-light-induced metal-free catalytic system was developed for the synthesis of arylphosphonates starting from arylhydrazines and trialkylphosphites. By using the inexpensive eosin B as catalyst, sub-stoichiometric amounts of DABCO, and ambient air as oxidant, diverse arylphosphonates were obtained under visible-light irradiation. Notably, this catalytic system is suitable for gram-scale reaction by utilizing sunlight as an illumination source.
- Li, Rui,Chen, Xiaolan,Wei, Shengkai,Sun, Kai,Fan, Lulu,Liu, Yan,Qu, Lingbo,Zhao, Yufen,Yu, Bing
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supporting information
p. 4807 - 4813
(2018/12/11)
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- Visible-Light-Mediated Metal-Free Synthesis of Aryl Phosphonates: Synthetic and Mechanistic Investigations
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This work describes a straightforward access to a large variety of aryl phosphonates by the simple combination of diaryliodonium salts with phosphites in the presence of a base and under visible-light illumination. The reaction proceeds smoothly, tolerates various functionalities, and was applied for the synthesis of pharmaceutically relevant compounds. Mechanistic investigations, including EPR, NMR, and DFT calculations, support the postulated reaction mechanism.
- Lecroq, William,Bazille, Pierre,Morlet-Savary, Fabrice,Breugst, Martin,Lalevée, Jacques,Gaumont, Annie-Claude,Lakhdar, Sami
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supporting information
p. 4164 - 4167
(2018/07/29)
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- Direct Aryloxylation/Alkyloxylation of Dialkyl Phosphonates for the Synthesis of Mixed Phosphonates
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A strategy for the direct functionalization strategy of inertial dialkyl phosphonates with hydroxy compounds to afford diverse mixed phosphonates with good yields and functional-group tolerance has been developed. Mechanistic investigations involving both NMR studies and DFT studies suggest that an unprecedented highly reactive PV species (phosphoryl pyridin-1-ium salt), a key intermediate for this new synthetic transformation, is generated in situ from dialkyl phosphonate in the presence of Tf2O/pyridine.
- Huang, Hai,Denne, Johanna,Yang, Chou-Hsun,Wang, Haobin,Kang, Jun Yong
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supporting information
p. 6624 - 6628
(2018/05/14)
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- Novel approach to metal-induced oxidative phosphorylation of aromatic compounds
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We propose a new approach to the phosphorylation of benzenes bearing both electron withdrawing and electron donating substituents on the ring and some coumarins (coumarin, 6-methylcoumarin, 7-methylcoumarin) under the action of dialkyl H-phosphonate (RO)
- Khrizanforov,Strekalova,Kholin,Khrizanforova,Kadirov,Gryaznova,Budnikova
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p. 133 - 141
(2016/11/03)
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- Decarbonylative Phosphorylation of Amides by Palladium and Nickel Catalysis: The Hirao Cross-Coupling of Amide Derivatives
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Considering the ubiquity of organophosphorus compounds in organic synthesis, pharmaceutical discovery agrochemical crop protection and materials chemistry, new methods for their construction hold particular significance. A conventional method for the synthesis of C?P bonds involves cross-coupling of aryl halides and dialkyl phosphites (the Hirao reaction). We report a catalytic deamidative phosphorylation of a wide range of amides using a palladium or nickel catalyst giving aryl phosphonates in good to excellent yields. The present method tolerates a wide range of functional groups. The reaction constitutes the first example of a transition-metal-catalyzed generation of C?P bonds from amides. This redox-neutral protocol can be combined with site-selective conventional cross-coupling for the regioselective synthesis of potential pharmacophores. Mechanistic studies suggest an oxidative addition/transmetallation pathway. In light of the importance of amides and phosphonates as synthetic intermediates, we envision that this Pd and Ni-catalyzed C?P bond forming method will find broad application.
- Liu, Chengwei,Szostak, Michal
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p. 12718 - 12722
(2017/10/06)
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- Ar-P bond construction by the Pd-catalyzed oxidative cross-coupling of arylsilanes with H-phosphonates via C-Si bond cleavage
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A novel and efficient methodology that allows for the construction of Ar-P bonds via the Pd-catalyzed oxidative cross-coupling reaction of various arylsilanes with H-phosphonates leading to valuable arylphosphonates has been developed.
- Luo, Haiqing,Liu, Haidong,Chen, Xingwei,Wang, Keke,Luo, Xuzhong,Wang, Kejun
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supporting information
p. 956 - 958
(2017/01/17)
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- A new magnetically recoverable heterogeneous palladium catalyst for phosphonation reactions in aqueous micellar solution
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A new heterogeneous palladium complex of 2-aminothiophenol supported on nanomagnetic γ-Fe2O3 was synthesized and characterized using various methods. The catalyst was used as a magnetically recoverable heterogeneous palladium catalyst for phosphonation reactions via C-P bond formation. Using this method, a wide range of electrophilic benzenes was coupled successfully with phosphite esters (triethyl/tri-isopropyl/triphenylphosphite and diethyl/di-isopropyl/diphenylphosphite) in aqueous micellar solution to generate the corresponding arylphosphonates in good to high yields. The catalyst was separated using an external magnet and reused for six consecutive cycles without any significant loss of its reactivity.
- Sobhani, Sara,Zeraatkar, Zohre
-
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- Nickel-catalyzed phosphorylation of aryl triflates with P([Formula presented] compounds
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A nickel-catalyzed phosphorylation of aryl triflates with P([Formula presented] compounds is disclosed. This reaction can proceed smoothly under a mild reaction condition, producing the corresponding aryl phosphorus compounds in good to high yields.
- Yang, Jia,Xiao, Jing,Chen, Tieqiao,Han, Li-Biao
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p. 120 - 124
(2016/08/23)
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- Nickel-Catalyzed Phosphorylation of Phenol Derivatives via C-O/P-H Cross-Coupling
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An efficient nickel-catalyzed phosphorylation of phenol derivatives with P(O)-H compounds via C-O/P-H cross-coupling is described. Under the reaction conditions, various phenyl pivalates coupled readily with hydrogen phosphoryl compounds to afford the corresponding coupling products aryl phosphonates and aryl phosphine oxides in good to high yields.
- Yang, Jia,Xiao, Jing,Chen, Tieqiao,Han, Li-Biao
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p. 3911 - 3916
(2016/05/24)
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- P-Arylation of Dialkyl Phosphites and Secondary Phosphine Oxides with Arynes
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The novel P-arylation of dialkyl phosphites and secondary phosphine oxides with arynes has been achieved. The reactions produce dialkyl arylphosphonates in 71-99% yield and tertiary phosphine oxides in 68-92% yield under mild conditions.
- Chen, Qian,Yan, Xinxing,Du, Zhiyun,Zhang, Kun,Wen, Chunxiao
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p. 276 - 281
(2016/01/15)
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- The Cu-catalyzed C-P coupling of phosphonate esters with arylboronic acids
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Copper-catalyzed C-P cross coupling of phosphonate esters with arylboronic acids has been developed. The reaction provided an efficient method for aryl phosphonates under mild conditions.
- Wan,Zhao,Wang,Zhang,Li
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p. 150 - 153
(2016/03/12)
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- Pd-catalyzed P-arylation of triarylantimony dicarboxylates with dialkyl H-phosphites without a base: Synthesis of arylphosphonates
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The reaction of triarylantimony diacetates [Ar3Sb(OAc)2] with dialkyl H-phosphites [H-PO(OR)2] in the presence of a Pd(PPh3)4 (5 mol%) catalyst led to the formation of arylphosphonates in moderate to excellent yield under base-free conditions. This reaction is the first example of carbon-phosphorus bond formation by using an organoantimony compound as a pseudo-halide.
- Matsumura, Mio,Dong, Yuqiang,Kakusawa, Naoki,Yasuike, Shuji
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p. 130 - 133
(2015/02/19)
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- First reusable ligand-free palladium catalyzed C-P bond formation of aryl halides with trialkylphosphites in neat water
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A reusable ligand-free palladium catalyzed phosphonation of aryl iodides, bromides and chlorides with trialkylphosphites is described for the first time in neat water. The aryl phosphonates are obtained in good to excellent yields. The reaction can be also performed with Ni(II) with longer reaction time. The role of tetrabutylammonium bromide in this reaction as reducing agent for generation of Pd(0) at room temperature is also demonstrated. Pd(0)/TBAB was easily reused for three runs without decreasing the efficiency.
- Iranpoor, Nasser,Firouzabadi, Habib,Rajabi Moghadam, Khashayar,Motavalli, Somayeh
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p. 55732 - 55737
(2015/02/05)
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- Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
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The synthesis of tertiary phosphine oxides from phosphonates was achieved reliably and in good to excellent yields using stoichiometric amounts of alkyl or aryl Grignard reagents and sodium trifluoromethanesulfonate (NaOTf). In the absence of the NaOTf additive, covalent coordination oligomers of magnesium and phosphorus species dominate the reaction, producing very low yields of phosphine oxide, but high conversions of the phosphonate starting material. Mechanistic studies revealed that a five-coordinate phosphorus species - not a phosphinate - is the reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon-phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-2-yldimethylphosphine, or methyl JohnPhos) and a classic bidentate phosphine, bis(diphenylphosphino)propane (dppp), were synthesized in excellent yields.
- Kendall, Alexander J.,Salazar, Chase A.,Martino, Patrick F.,Tyler, David R.
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supporting information
p. 6171 - 6178
(2015/02/19)
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- Experimental and theoretical study on palladium-catalyzed c-p bond formation via direct coupling of triarylbismuths with p(o)-h compounds
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A novel and highly efficient Pd-catalyzed cross-coupling of triarylbismuths with a variety of P(O)-H compounds has been developed that proceeds smoothly without exclusion of moisture or air and provides a general and powerful tool for the preparation of various valuable arylphosphonates, arylphosphinates, and arylphosphine oxides, with high atom-economy, operational simplicity of the procedure, and good to high yield. The coupling reaction is the first example of transition-metal-catalyzed C-P bond construction using triarylbismuth compounds as substrates. DFT calculations reveal that C-P bond formation is the rate-determing step.
- Wang, Tao,Sang, Shuai,Liu, Liu Leo,Qiao, Hongwei,Gao, Yuxing,Zhao, Yufen
-
supporting information
p. 608 - 617
(2014/04/03)
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- Palladium-catalyzed desulfitative cross-coupling reaction of sodium arylsulfinates with H-phosphonate diesters
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A novel and convenient palladium-catalyzed cross-coupling reaction of H-phosphonate diesters with sodium arylsulfinates was developed via desulfitation in the presence of silver carbonate and tetra-butylammonium chloride. This method is highly efficient and provides a rapid access to a broad spectrum of arylphosphonate diesters in good to excellent yields.
- Miao, Tao,Wang, Lei
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supporting information
p. 967 - 971
(2014/04/03)
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- Stereoselective synthesis of phosphoryl-substituted phenols
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Copper-catalyzed C-X activation-phosphorylation of aryls bearing different groups has been achieved using P(O)-H compounds as efficient phosphorylation reagents without the assistance of any ligand. Optically active H-phosphinates can also act as good substrates in the reaction, giving the (Sp)-phosphoryl substituted phenolic compounds stereospecifically with retention of configuration at the phosphorus center. Furthermore, it is shown that the migration of phosphorus on O-aryl phosphonates from oxygen to carbon also proceeds stereospecifically to produce the corresponding optically active (Rp)-phosphoryl-substituted phenolic compounds with retention of configuration at phosphorus via treatment with lithium diisopropylamide (LDA). Plausible mechanisms have been proposed for these reactions.
- Xiong, Biquan,Li, Mei,Liu, Yanxi,Zhou, Yongbo,Zhao, Changqiu,Goto, Midori,Yin, Shuang-Feng,Han, Li-Biao
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supporting information
p. 781 - 794
(2014/04/03)
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- Palladacycle-catalyzed phosphonation of aryl halides in neat water
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An efficient and generally applicable protocol for the palladacycle- catalyzed arylation of diisopropyl H-phosphonate in water was developed. The remarkable features of this C-P bond-forming reaction include wide substrate scope including the inactive electron-rich and electron-neutral aryl chlorides, the weak inorganic base KF instead of strong bases such as KOtBu or NaOtBu for the activation of C-Cl bond, and the addition of isopropanol to avoid the decomposition of diisopropyl H-phosphonate.
- Xu, Kai,Yang, Fan,Zhang, Guodong,Wu, Yangjie
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supporting information
p. 1055 - 1060
(2013/07/26)
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- Synthesis of aryl and arylmethyl phosphonates by cross-coupling of aryl or arylmethyl halides (X = I, Br and Cl) with diisopropyl H-phosphonate
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An efficient and generally applicable protocol for the palladacycle- catalysed arylation or K2CO3-promoted arylmethylation of diisopropyl H-phosphonate has been developed. The remarkable features of the palladacycle-catalysed arylation reaction include wide substrate scope (aryl iodides, bromides and chlorides), significant shortening of the reaction time (2 or 3 h) and a low catalyst loading of 1 mol-%. Note that with the base K 2CO3 as promoter, arylmethylation could be achieved without any palladium catalyst. Moreover, the first example of a palladium-catalysed phosphonation of inactive electron-rich aryl chlorides with tBuOK as the base has been realized. This result could be considered an important improvement and complement to earlier work of Montchamp and Han, whose catalytic systems are typically compatible with electron-deficient and electron-neutral aryl chlorides.
- Xu, Kai,Hu, Hao,Yang, Fan,Wu, Yangjie
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supporting information
p. 319 - 325
(2013/02/25)
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- Phosphorus-carbon bond formation: Palladium-catalyzed cross-coupling of H-phosphinates and other P(O)H-containing compounds
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Two generally applicable systems have been developed for the cross-coupling of P(O)H compounds with Csp2-X and related partners. Palladium catalysis using a ligand/additive combination, typically either xantphos/ethylene glycol or 1,1-bis(diphenylphosphino)ferrocene/1,2- dimethoxyethane, with diisopropylethylamine as the base, proved to be generally useful for the synthesis of numerous P-C containing compounds. Routinely, 2 mol% of catalyst are employed (less than half the amount typically employed in most other literature reports). In most cases, excellent results are obtained with a variety of electrophiles (RX, where R=alkenyl, allyl, alkynyl, etc.). The full account of our studies is disclosed, including tandem hydrophosphinylation/ coupling and coupling/coupling for doubly catalytic phosphorus-carbon bond formation. The methodology compares favorably with any existing literature report. The use of an additive appears to be a generally useful strategy to control the reactivity of phosphinylidene compounds. Copyright
- Berger, Olivier,Petit, Christelle,Deal, Eric L.,Montchamp, Jean-Luc
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supporting information
p. 1361 - 1373
(2013/06/26)
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- Copper-catalyzed C-P bond construction via direct coupling of phenylboronic acids with H-phosphonate diesters
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A mild and efficient method was developed for the copper-catalyzed additions of H-phosphonate diesters to boronic acids under the copper catalyst system Cu2O/1,10-phenanthroline. To the best of our knowledge this finding is the first example of a copper-catalyzed synthesis of aryl phosphonates from arylboronic acids and H-phosphonate dialkyl esters.
- Zhuang, Rongqiang,Xu, Jian,Cai, Zhenshi,Tang, Guo,Fang, Meijuan,Zhao, Yufen
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supporting information; experimental part
p. 2110 - 2113
(2011/06/20)
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- Preparation of arylphosphonates by palladium(O)-catalyzed cross-coupling in the presence of acetate additives: Synthetic and mechanistic studies
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An efficient protocol for the synthesis of arylphosphonate diesters via a palladium-catalyzed cross-coupling of H-phosphonate diesters with aryl electrophiles, promoted by acetate ions, was developed. A significant shortening of the cross-coupling time in the presence of the added acetate ions was achieved for bidentate and monodentate supporting ligands, and for different aryl electrophiles (iodo, bromo and triflate derivatives). The reaction conditions were optimized in terms of amount of the catalyst, supporting ligands, and source of the acetate ion used. Various arylphosphonates, including those of potential biological significance, were synthesized using this newly developed protocol. Some mechanistic aspects of the investigated reactions are also discussed.
- Kalek, Marcin,Jezowska, Martina,Stawinski, Jacek
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experimental part
p. 3207 - 3216
(2010/04/26)
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- Anomalous reaction of ethyl bromofluoro- and difluoro-acetates with dialkylphosphonites
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The Michaelis-Arbuzov reaction of ethyl α-bromo-α-fluoro- and α, α-difluoro-acetates with dialkyl phenylphosphonites leads to the formation of unusual products including a fluorophosphinate. The reaction of ethyl bromofluoracetate with diisopropyl- and dimethyl-phenylphosphonites furnishes a complex mixture of eight and five compounds respectively. Five different compounds are obtained when ethyl bromodifluoroacetate is reacted with diisopropyl phenylphosphonite. Dimethyl phenylphosphonite yields three compounds when heated with bromochloromethane. The probable mechanism of formation of the compounds and their mass spectral characterization using GC-MS, tandem MS-MS and DART techniques are presented in this paper. Copyright Taylor & Francis Group, LLC.
- Durst,Rohrbaugh,Smith,Nilles,Connell,Laramee,Munavalli
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experimental part
p. 2655 - 2668
(2009/09/25)
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- Revisiting the Hirao cross-coupling: improved synthesis of aryl and heteroaryl phosphonates
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The palladium-catalyzed cross-coupling of dialkylphosphite with aromatic electrophiles (Hirao coupling) was re-investigated. Some limitations in terms of palladium loadings and substrate reactivity are alleviated with the use of Pd(OAc)2 comple
- Belabassi, Yamina,Alzghari, Saeed,Montchamp, Jean-Luc
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p. 3171 - 3178
(2008/12/22)
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- Phosphonation of arenes with dialkyl phosphites catalyzed by Mn(II)/Co(II)/O2 redox couple
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Arylphosphonates were first synthesized through a catalytic phosphonation of various arenes with dialkyl phosphites under the influence of an Mn(OAc) 2/Co(OAc)2/O2 redox couple. For instance, the reaction of benzene with d
- Kagayama, Takashi,Nakano, Atsushi,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 407 - 409
(2007/10/03)
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- Proline/pipecolinic acid-promoted copper-catalyzed P-arylation
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We have developed a convenient and efficient approach for P-arylation of organophosphorus compounds containing P-H. Using commercially available and inexpensive proline and pipecolinic acid as the ligands greatly improved the efficiency of the coupling reactions, so the method can provide an entry to arylphosphonates, arylphosphinates and arylphosphine oxides.
- Huang, Cheng,Tang, Xu,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
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p. 5020 - 5022
(2007/10/03)
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- A versatile and efficient ligand for copper-catalyzed formation of C-N, C-O, and P-C bonds: Pyrrolidine-2-phosphonic acid phenyl monoester
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A new and readily available bidentate ligand, namely, pyrrolidine-2- phosphonic acid phenyl monoester (PPAPM), has been developed for the copper-catalyzed formation of C-N, C-O, and P-C bonds, and various N-, O-, and P-arylation products were synthesized in good to excellent yields by using the CuI/PPAPM catalyst system. Addition of the PPAPM ligand greatly increases the reactivity of the copper catalyst, and the resulting versatile and efficient catalyst system is of widespread and practical application in cross-coupling reactions.
- Rao, Honghua,Jin, Ying,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
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p. 3636 - 3646
(2008/02/03)
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- Reactivity of diacyloxyiodobenzenes toward trivalent phosphorus nucleophiles
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The reaction of diacyloxyiodobenzenes and tetravalent phosphorus nucleophiles was investigated. It was established that both H-phosphonates and secondary phosphine oxides react with diacetoxyiodobenzene in alcohols in the presence of sodium alcoholates yi
- Makowiec, Slawomir,Rachon, Janusz
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p. 352 - 359
(2007/10/03)
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- Irreversibility of single electron transfer occurring from trivalent phosphorus compounds to iron(III) complexes in the presence of ethanol
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Various types of trivalent phosphorus compounds (1; Ph(3-n)P(OR)n) underwent single electron transfer (SET) to unsubstituted (2H) and 5-chloro-substituted tris(1, 10-phenanthroline)iron(III) complexes (2Cl) in the presence of ethanol in acetonitrile, resulting in the reduction of 2 to the corresponding iron(II) complexes. The rate constants (kp) for the overall SET process were determined spectrophotometrically to show that within each series of 1 with an identical alkoxy group OR, log kp correlates linearly with the difference in the half-wave potentials (ΔE1/2) between 1 and 2. The slope of each correlation line gave an α-value for each series of 1. The α-values were significantly smaller than unity, indicating that the SET step is irreversible, even though this step is endothermic. The trivalent phosphorus radical cation 1.+ generated in the SET step undergoes a rapid ionic reaction with ethanol, which is certainly the origin of the irreversibility. Upon examining the α-values more closely, it was found that the transition state of the SET step becomes earlier with increasing bulkiness of the substituent OR. It is concluded that 1 and 2 form a tight encounter complex to undergo SET from the former to the latter.
- Yasui, Shinro,Itoh, Kenji,Tsujimoto, Munekazu,Ohno, Atsuyoshi
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p. 1311 - 1318
(2007/10/03)
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- Hypervalent iodine in synthesis. 52. Palladium-catalyzed arylation of O,O-dialkyl phosphites with diaryliodonium salts: A convenient method for synthesis of arylphosphonates
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Palladium-catalyzed coupling reaction of diaryliodonium salts with O,O-dialkyl phosphites gave arylphosphonates in good yields.
- Zhou,Chen
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p. 3289 - 3294
(2007/10/03)
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- Microwave irradiation in organophosphorus chemistry 1: The Michaelis-Arbuzov reaction
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A diverse series of phosphonate esters have been prepared using a domestic microwave oven. The microwave enhanced Michaelis-Arbuzov reaction shows remarkable rate acceleration under microwave irradiation and allows the facile synthesis, and in certain cases easy workup, of alkyl, α-substituted and aryl phosphonates.
- Kiddle, James J.,Gurley, Alison F.
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p. 195 - 205
(2007/10/03)
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- Palladium-Catalyzed Phase-Transfer Arylation of Dialkyl Phosphonates
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Palladium-catalyzed phase-transfer arylation of dialkyl phosphonates with various iodo- and bromoarenes has been studied. The arylation has also been effected in the absence of ligand. A simple preparative procedure for synthesizing arylphosphonic acids has been developed.
- Kabachnik,Solntseva,Izmer,Novikova,Beletskaya
-
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- Reaction of trivalent phosphorus compounds with an Fe(III) complex in the presence of alcohol. Single electron transfer accompanied by a P-O bond formation
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Reactions of various types of trivalent phosphorus compounds with iron(III) complex in the presence of ethanol have been examined kinetically, showing that the single electron transfer from the former compounds to the latter is followed by rapid reaction of the resulting trivalent phosphorus radical cations with ethanol.
- Yasui, Shinro,Itoh, Kenji,Tsujimoto, Munekazu,Ohno, Atsuyoshi
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p. 1019 - 1020
(2007/10/03)
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- THE KINETICS AND MECHANISM OF THE REACTION OF TRICO-ORDINATE PHOSPHORUS COMPOUNDS WITH TETRACYANOQUINODIMETHANE AND TETRACYANOETHYLENE
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Trico-ordinate phosphorus compounds, ArnP(OPri)3-n where n = 0-3, react with tetracyanoquinodimethane (TCNQ) in acetonitrile in the presence of water to give the corresponding phosphoryl compounds, ArnP(O)(OPri)3-n and 1,4-bis-dicyanomethylbenzene (TCNQH2) in quantitative yield.The kinetics of these reactions are reported together with the Hammett ρ-parameters from variation of substituents in the aryl group for n = 1,2 and 3.On the basis of the available evidence, a mechanism is proposed involving one electron transfer from phosphorus (the donor) to TCNQ.A kinetic study of the reaction of triarylphosphines with TCNE in aqueous acetonitrile, however, suggests rate-limiting nucleophilic attack on nitrogen rather than the radical cation mechanism.Key words: Tricoordinate phosphorus, tetracyanoquinodimethane, tetracyanoethylene, kinetics, mechanism.
- Hall, C. D.,Beer, P. D.,Powell, R. L.,Naan, M. P.
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p. 145 - 156
(2007/10/02)
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- The Kinetics and Mechanism of the Reaction of Tricoordinate Phosphorus Compounds with Diaryl Trisulfides
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Kinetic data and activation parameters are reported for the reaction of a series of tricoordinate phosphorus compounds, , with diaryl trisulfides.The second-order rate coefficients for series of arylphosphines, phosphinites and phosphonites, correlate with the Hammett ? constants of the aryl substituents with ρ values of -1.1, -1.1 and -1.1 respectively and these results are discussed in terms of a biphilic mechanism analogous to that proposed for the reaction of tricoordinate phosphorus with S8.
- Hall, C. Dennis,Tweedy, Bruce R.,Kayhanian, Robert,Lloyd, John R.
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p. 775 - 779
(2007/10/02)
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- Oxidative Phoshonylation of Aromatics with Ammonium Cerium(IV) Nitrate
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Arylphosphonates 5 and 6 can be prepared in good yields in a one-step synthesis starting from arenes with tri- or diethylphosphites and cerium ammonium nitrate (CAN) as oxidant.The seletivity of the oxidative phosphonylation is relatively low; the reactive species is a phosphite radical cation.
- Kottmann, Hariolf,Skarzewski, Jacek,Effenberger, Franz
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p. 797 - 801
(2007/10/02)
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- SYNTHESIS AND NMR SPECTROSCOPIC INVESTIGATION OF PHENYLPHOSPHORYL DERIVATIVES
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The syntheses of 16 phenyl- (1 and 3) and phenylthiophosphoryl (2) derivatives are described.The 13C and 17O NMR data sensitively reflect electron density changes in the phosphoryl substituents caused by p?-d? back-donation from X/Y to P.Taft constants ?1 and ?R0 were derived for 16 phosphoryl substituents.
- Duddeck, Helmut,Lecht, Rainer
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p. 169 - 178
(2007/10/02)
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- Palladium-Catalyzed Reaction of Aryl Polyfluoroalkanesulfonates with O,O-Dialkyl Phosphonates
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Arylphosphonates were synthesized by the reaction of aryl polyfluoroalkanesulfonates with O,O-dialkyl phpsphonates in the presence of triethylamine under palladium catalysis in good to excellent yield.
- Lu, Xiyan,Zhu, Jingyang
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p. 726 - 727
(2007/10/02)
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- The Selective Dealkylation of Mixed Esters of Phosphoric Acid and Phenylphosphonic Acid Using Cation Exchange Resin
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Cation exchange resin (SO3H) is a highly selective dealkylation reagent for mixed esters of phosphorus oxyacids bearing primary and secondary alkyl groups.The desired products which were produced by dealkylation of the secondary alkyl group were obtained in high yields under anhydrous and mild conditions.Keywords - dealkylation; cation exchange resin; carbonium ion; phosphorus oxyacid ester; trialkyl phosphate; dialkyl phenylphosphonate; p-toluenesulfonic acid
- Nitta, Yoshihiro,Arakawa, Yasushi
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p. 3121 - 3129
(2007/10/02)
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- The Kinetics and Mechanism of the Reactions of Acyclic Trico-ordinate Phosphorus Compounds with Diethyl Peroxide
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The kinetics of the reactions of acyclic phosphinites, phosphonites, and phosphines with diethyl peroxide in benzene or acetonitrile as solvent are reported together with the activation parameters for phosphinites and phosphonites and Hammett ρ values for all three types of trico-ordinate phosphorus.The data reveal a bimolecular, non-polar transition state for each reaction with ρ values are virtually independent of the nature of the trico-ordinate phosphorus species.
- Lloyd, John R.,Lowther, Nicholas,Hall, C. Dennis
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p. 245 - 250
(2007/10/02)
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