- AlCl3 Catalyzed Oxo-Diels-Alder and Wittig-Type Reaction of 2,3-Dimethyl-1,3-Butadiene with Acyl Phosphonates
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Different aliphatic and aromatic acyl phosphonates were synthesized using Arbuzov reaction and subjected to Oxo-Diels-Alder (ODA) reaction with 2,3-dimethyl-1,3-butadiene at-78°C. AlCl3 was found the best catalyst to obtain the desired ODA products from a
- Nadeem,Demir, Ayhan S.
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- Markovnikov-addition of H-phosphonates to terminal alkynes under metal- And solvent-free conditions
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An addition of H-phosphonates to aryl alkynes was realized under solvent- and metal-free conditions, affording Markovnikov-selective α-vinylphosphonates in moderate to good yields. A wide range of aryl alkynes could be applied for the reaction. A tentative mechanism of addition-substitution was proposed based onin situ31P {1H} NMR studies.
- Huang, Xian-Qiang,Lian, Yongjian,Lv, Yongzheng,Wang, Yongjie,Xin, Nana,Zhao, Chang-Qiu
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p. 24991 - 24994
(2021/07/29)
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- Hydrophosphorylation of Alkynes Catalyzed by Palladium: Generality and Mechanism
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We carried out a comprehensive study on the generality, scope, limitations, and mechanism of the palladium-catalyzed hydrophosphorylation of alkynes with P(O)-H compounds (i.e., H-phosphonates, H-phosphinates, secondary phosphine oxides, and hypophosphinic acid). For H-phosphonates, Pd/dppp was the best catalyst. Both aromatic and aliphatic alkynes, with a variety of functional groups, were applicable to produce the Markovnikov adducts in high yields with high regioselectivity. Aromatic alkynes showed higher reactivity than aliphatic alkynes. Terminal alkynes reacted faster than internal alkynes. Sterically crowded H-phosphonates disfavored the addition. For H-phosphinates and secondary phosphine oxides, Pd/dppe/Ph2P(O)OH was the catalyst of choice, which led to highly regioselective formation of the Markovnikov adducts. By using Pd(PPh3)4 as the catalyst, hypophosphinic acid added to terminal alkynes to give the corresponding Markovnikov adducts. Phosphinic acids, phosphonic acid, and its monoester were not applicable to this palladium-catalyzed hydrophosphorylation. Mechanistic studies showed that, with a terminal alkyne, (RO)2P(O)H reacted, like a Br?nsted acid, to selectively generate the α-alkenylpalladium intermediate via hydropalladation. On the other hand, Ph(RO)P(O)H and Ph2P(O)H gave a mixture of α- and β-alkenylpalladium complexes. In the presence of Ph2P(O)OH, hydropalladation with this acid took place first to selectively generate the α-alkenylpalladium intermediate. A subsequent ligand exchange with a P(O)H compound gave the phosphorylpalladium intermediate which produced the Markovnikov adduct via reductive elimination. Related intermediates in the catalytic cycle were isolated and characterized.
- Chen, Tieqiao,Zhao, Chang-Qiu,Han, Li-Biao
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supporting information
p. 3139 - 3155
(2018/03/08)
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- Pd-Catalysed Suzuki coupling of α-bromoethenylphosphonates with organotrifluoroborates: A general protocol for the synthesis of terminal α-substituted vinylphosphonates
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A general and robust protocol for the synthesis of terminal α-substituted vinylphosphonates via Suzuki coupling of α-bromovinylphosphonates with organotrifluoroborates has been successfully developed. This method features a broad substrate scope, great functional group compatibilities, and easy scale-up ability. In addition to easy access of nucleophiles, a straightforward synthesis of electrophiles was also realized with diethyl α-bromoethenylphosphonate as the starting material. With a combination of Pd2(dba)3/SPhos as the catalyst, a range of α-alkyl, aryl, heteroaryl, and alkynyl substituted ethenylphosphonates could be nicely accessed under mild conditions. As a synthetic application, the terminal vinylphosphonate was utilized as an effective Michael acceptor in the visible-light-promoted Giese reaction.
- Zhang, Li,Fang, Yewen,Jin, Xiaoping,Xu, Housan,Li, Ruifeng,Wu, Hao,Chen, Bin,Zhu, Yiming,Yang, Yi,Tian, Zongming
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supporting information
p. 8985 - 8989
(2017/11/09)
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- A alkene base phosphine acid ester compound preparation method
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The invention discloses a preparation method for an alkenyl phosphate compound. By taking palladium acetate or tetra(triphenylphosphine) palladium as a catalyst, an alkali, a ligand, a diazo compound and a halide or an alkali, tosylhydrazone and a halide react under protection of an N2 atmosphere in an organic solvent to obtain the alkenyl phosphate compound RR'C=C(Ar)(P(O)(OMe)2), wherein Ar represents substituted or unsubstituted aryl comprising phenyl, naphthyl and heterocyclic rings; R and R' represent substituted or unsubstituted aryl, alkyl, alkenyl or hydrogen. According to the reaction referred to the invention, an E-configuration alkenyl phosphate compound can be smoothly obtained. The preparation method is convenient and simple to operate and has good tolerance and universality on functional groups. Moreover, the use level of the catalyst is relatively small, neither the reagent nor the solvent is specially treated, and the reaction cost is relatively low, so that the preparation method can be widely used for preparing the alkenyl phosphate compound.
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Paragraph 0185-0189
(2017/07/26)
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- α-Phosphonovinyl Arylsulfonates: An Attractive Partner for the Synthesis of α-Substituted Vinylphosphonates through Palladium-Catalyzed Suzuki Reactions
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It has been demonstrated that a variety of α-phosphonovinyl arylsulfonates with electron-neutral, -donating, and -withdrawing groups on the phenyl ring could be conveniently and efficiently prepared. In the presence of a Pd(OAc)2/SPhos-based catalyst, various organoboron compounds could be employed as the nucleophilic coupling partners, such as organoboronic acids, boronate esters, and organotrifluoroborates. The newly developed O-centered electrophiles could couple with a multitude of aryl, heteroaryl, and alkylboron reagents, to give α-substituted vinylphosphonates in moderate to excellent yields. Generally, the Suzuki reaction is tolerant of extensive substitution at the aromatic ring of both electrophilic and nucleophilic coupling partners. As in the case of the Suzuki reaction of 8-quinolineboronic acid, proper choice of α-phosphonovinyl arylsulfonates is critical to efficient coupling. Moreover, the prospect for application of this method to complex synthesis has been demonstrated through the coupling of estrone-derived arylborons. The present protocol also features mild conditions and high efficiency. A new and attractive coupling partner for the synthesis of α-substituted vinylphosphonates through Suzuki reactions has been developed. The developed O-centered electrophiles couple with various organoboron reagents to give α-substituted vinylphosphonates in moderate to excellent yields. This protocol features broad substrate scope, mild conditions, and high efficiency.
- Fang, Yewen,Zhang, Li,Jin, Xiaoping,Li, Jinjian,Yuan, Meijuan,Li, Ruifeng,Wang, Tong,Wang, Tao,Hu, Hanjun,Gu, Juejun
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p. 1577 - 1587
(2016/04/05)
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- Synthesis of Alkenylphosphonates through Palladium-Catalyzed Coupling of α-Diazo Phosphonates with Benzyl or Allyl Halides
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An efficient method for the synthesis of organophosphonates through palladium-catalyzed coupling of α-diazo phosphonates with benzyl or allyl halides has been developed. Trisubstituted alkenylphosphonates bearing versatile functional groups can be easily accessed in good yields and with excellent stereoselectivity through this method. Moreover, with similar strategy α-substituted vinylphosphonates can also be attained by the palladium-catalyzed coupling reaction of N-tosylhydrazones and aryl bromides. Migratory insertion of palladium carbene is proposed as the key step in this reaction.
- Zhou, Yujing,Ye, Fei,Wang, Xi,Xu, Shuai,Zhang, Yan,Wang, Jianbo
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p. 6109 - 6118
(2015/06/30)
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- Applications of α-phosphonovinyl tosylates in the synthesis of α-arylethenylphosphonates via suzuki-miyaura cross-coupling reactions
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It has been demonstrated for the first time that α-phosphonovinyl tosylates could efficiently couple with a range of arylboronic acids to access α-arylethenylphosphonates. The unprecedented procedure exhibits excellent functional group tolerance, giving the terminal vinylphosphonates in good to excellent isolated yields (60-99%) under mild reaction conditions.
- Fang, Yewen,Li, Jinjian,Wu, Rong,Fang, Jianghua,Zhang, Li,Yuan, Meijuan,Li, Ruifeng,Jin, Xiaoping
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supporting information
p. 798 - 801
(2015/04/14)
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- A simple and efficient method for one-pot, three-component synthesis of terminal vinylphosphonates using a task-specific ionic liquid
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A convenient and practical method for the one-pot, three-component synthesis of terminal vinylphosphonates from readily available starting materials (aryl/alkyl/heteroaryl aldehydes, nitromethane and trialkylphosphites) through a tandem Henry-Michael reaction followed by nitro elimination in the presence of 5-hydroxypentylammonium acetate (5-HPAA) as a task-specific ionic liquid, is described. This method offers several advantages such as the use of a reusable and inexpensive ionic liquid, which is an environmentally benign reaction medium, and a simple reaction setup that does not require specialized equipment. The approach offers good yields of the products under mild reaction conditions. Georg Thieme Verlag Stuttgart New York.
- Sobhani, Sara,Honarmand, Moones
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supporting information
p. 236 - 240
(2013/03/13)
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- Enantioselective synthesis of chiral α-aryl or α-alkyl substituted ethylphosphonates via Rh-catalyzed asymmetric hydrogenation with a P-stereogenic BoPhoz-type ligand
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(Chemical Equation Presented) An enantioselective synthesis of optically active 1-aryl or 1-alkyl substituted ethylphosphonates, based on the first Rh-catalyzed asymmetric hydrogenation of corresponding α,β- unsaturated precursors with a P-stereogenic BoPhoz-type ligand under the mild condition, was developed, in which a wide range of 1-aryl or 1-alkyl substituted ethylphosphonates were achieved in up to 98% ee.
- Wang, Dao-Yong,Hu, Xiang-Ping,Deng, Jun,Yu, Sai-Bo,Duan, Zheng-Chao,Zheng, Zhuo
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supporting information; experimental part
p. 4408 - 4410
(2009/09/08)
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- Trimethylsilylated 1,3-dienes or styrenes from the reaction between trimethylsilyldiazomethane and vinyl or aryl ketenes
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The reaction between trimethylsilyldiazomethane and aryl or vinyl ketenes 2 and 7, bearing an electron withdrawing group on the ketene moiety, gave rise in moderate to good yields to the trimethylsilylated styrenes 3-5 or 1,3 dienes 8a-d resulting from the decarbonylation of presumed intermediate cyclopropanones.
- Leost, Francoise,Doutheau, Alain
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p. 847 - 848
(2007/10/03)
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- Nucleophilic Addition-Elimination Reactions of N-(p-Tolylsulphonyl)vinylsulphoximines: Preparation of α-Methylene Nitriles and Phosphonates
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Treatment of N-(p-tolylsulphonyl)vinylsulphoximines (1) with lithium cyanide in DMF at room temperature leads to efficient formation of α,β-unsaturated nitriles (3), via a Michael addition-proton transfer-elimination process, in which the polarity of the double bond is reversed.Analogous reaction with lithium dimethylphosphonate leads to β-dimethylphosphonyl sulphoximines (7), which are converted to α,β-unsaturated phosphonates (6) by treatment with NaOMe.
- Bailey, Peter L.,Jackson, Richard F. W.
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p. 3119 - 3122
(2007/10/02)
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- New Synthesis and Hydroboration of Vinylphosphonates
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The Arbuzov reaction of trimethyl and triethyl phosphites with acyl chlorides gave 1-oxoalkylphosphonates in 57-80percent yields.The Wittig reaction of the phosphonates with methylenetriphenylphosphorane gave vinylphosphonates in 25-59percent yields.Hydroboration of vinylphosphonates in oxolane gave 2-hydroxyethylphosphonates in 50-65percent yields.The procedure seems to be a good synthetic method to afford 1-alkyl-substituted 2-hydroxyethylphosphonates which have one more carbon atom than the starting 1-oxoalkylphosphonates.
- Yamashita, Mitsuji,Kojima, Mitsumasa,Yoshida, Hiroshi,Ogata, Tsuyoshi,Inokawa, Saburo
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p. 1625 - 1628
(2007/10/02)
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