1021-45-0Relevant academic research and scientific papers
Electrochemical Oxidative Difunctionalization of Alkenes to Access α-Oxygenated Ketones
Dai, Changhui,Shen, Yijie,Wei, Yifan,Liu, Ping,Sun, Peipei
, p. 13711 - 13719 (2021/10/01)
Dioxygenation of alkenes was developed by the combination of electrochemical synthesis and aerobic oxidation, leading to easy accessibility of α-oxygenated ketones in an eco-friendly fashion. Using air as the oxygen source and the absence of transition metals were the critical features of this protocol. A wide range of alkenes and N-hydroxyimides were found to be compatible and provided α-oxygenated ketones in moderate to high yields.
Catalyst-Free Difunctionalization of Activated Alkenes in Water: Efficient Synthesis of β-Keto Sulfides and Sulfones
Wang, Huamin,Wang, Guangyu,Lu, Qingquan,Chiang, Chien-Wei,Peng, Pan,Zhou, Jiufu,Lei, Aiwen
supporting information, p. 14489 - 14493 (2016/10/03)
Difunctionalization of activated alkenes, a powerful strategy in chemical synthesis, has been accomplished for direct synthesis of a series of β-keto sulfides and β-keto sulfones. The transformation, mediated by O2, proceeds smoothly in water and without any catalyst. Prominent advantages of this method include mild reaction conditions, purification simplicity, and gram-scale synthesis, underlining the practical utility of this methodology.
Copper(I)-catalyzed oxidation of alkenes using molecular oxygen and hydroxylamines: Synthesis and reactivity of α-oxygenated ketones
Andia, Alexander A.,Miner, Matthew R.,Woerpel
supporting information, p. 2704 - 2707 (2015/06/16)
The copper(I)-catalyzed oxidation of alkenes with molecular oxygen and N-hydroxyphthalimide (NHPI) or N-hydroxybenzotriazole (HOBt) provided α-oxygenated ketones. The reaction proceeded under a balloon of O2 at room temperature to furnish the dioxygenated products in 50-90% yield. These compounds, particularly the HOBt derivatives, can be further functionalized with phosphorus, nitrogen, and sulfur nucleophiles to give synthetically useful products.
Base-mediated tandem reaction of α-aryloxyacetophenones with phosphonates: Selective synthesis of enol phosphates
Song, Ren-Jie,Liu, Yan-Yun,Wu, Ji-Cheng,Xie, Ye-Xiang,Deng, Guo-Bo,Yang, Xu-Heng,Liu, Yu,Li, Jin-Heng
experimental part, p. 1119 - 1125 (2012/05/04)
A new, simple method for the synthesis of enol phosphates by base-mediated tandem reaction of α-aryloxyacetophenones with phosphonates is described. In the presence of Cs2CO3, a variety of -aryloxyacetophenones smoothly underwent the sequential O-P bond-forming/C-O bond cleavage/isomerization tandem reaction with phosphonates at room temperature, providing the corresponding enol phosphates in moderate to excellent yields. Georg Thieme Verlag Stuttgart · New York.
Asymmetric hydrogenation of α- Or β-acyloxy α,β- unsaturated phosphonates catalyzed by a Rh(i) complex of monodentate phosphoramidite
Zhang, Jinzhu,Dong, Kaiwu,Wang, Zheng,Ding, Kuiling
supporting information; experimental part, p. 1598 - 1601 (2012/03/22)
The Rh(i) complex of a monodentate phosphoramidite bearing a primary amine moiety (DpenPhos) has been disclosed to be highly efficient for the asymmetric hydrogenation of a variety of α- or β-acyloxy α,β- unsaturated phosphonates, providing the corresponding biologically important chiral α- or β-hydroxy phosphonic acid derivatives with excellent enantioselectivities (90->99% ee).
An efficient separation method for enol phosphate and corresponding β-ketophosphonate from their mixtures under aqueous conditions
Moorhoff, Cornelis M.
, p. 2069 - 2086 (2007/10/03)
Separation of a mixture β-ketophosphonate 3 and their corresponding enol phosphate 4 is efficiently carried out in aqueous alkaline solutions. Enol phosphate 4 is first extracted with hexanes:dichloromethane (19:1). Acidification of the aqueous layer followed by extraction of the β-ketophosphonate 3 with dichloromethane completes the separation. Thus, when 1-bromo-2,4-pentadione la reacted with triethyl phosphite to give diethyl (2,4-dioxopentyl)phosphonate 3a (Arbuzov-product) and the corresponding enol phosphate 4a (Perkow-product), separation of the two compounds was carried out using this method.
Comparative spectroscopic and theoretical studies on the conformation of some α-diethoxyphosphoryl carbonyl compounds and their α-ethylsulfonyl analogues
Olivato, Paulo R.
, p. 97 - 102 (2007/10/03)
Comparative vco IR analysis of β-carbonylphosphonates [XC(O)CH2P(O)(OR)2: X = Me 1, Ph 2, OEt 3, NEt2 4 and SEt 5; R = Et] (series I) and β-carbonylsulfones [XC(O)CH2SO2R: X = Me 6, Ph 7, OEt 8, NEt2 9 and SEt 10; R = Et] (series II) along with ab initio 6-31 G** calculations on la and 6a (R = Me) suggest the existence of only a single gauche conformer for series I. The negative carbonyl frequency shifts for both series follow approximately the electron-affinities of the π*co orbital of the parent compounds MeC(O)X 11-15. The less positive asymmetric sulfonyl frequency shifts (ΔvSO2) for II in relation to the phosphoryl frequency shifts (ΔvPO) for I and the larger negative carbonyl frequency shifts for II with respect to the corresponding values for I are in line with the upfield 13C NMR chemical shifts of the carbonyl carbon for II compared to I. These trends agree with the shorter O(SO2) ...C(CO) contact in comparison with the O(PO) ... C(CO) one and are discussed in terms of Olp→π*co charge transfer and electrostatic interactions, which are stronger for series II than for I, indicating that the sulfonyl oxygen atom is a better electron donor than the phosphoryl oxygen atom. Intrinsic geometrical parameters of O=S-CH2 and O=P-CH2 moieties seem to be responsible for this behaviour as indicated by X-ray study and ab initio calculations of dialkyl (methylsulfonyl)methylphosphonate MeSO2CH2P(O)(OR)2(R = Et l8, Me 18a). The Royal Society of Chemistry 2001.
Studies on organophosphorus compounds, 53: A new procedure for the synthesis of 1-alkyl or 1-aryl-1-hydroxy-2-nitroethylphosphonates under PTC conditions
Yuan,Cui,Wang,Feng,Chen,Li,Ding,Maier
, p. 258 - 260 (2007/10/02)
A series of dialkyl 1-alkyl- or 1-aryl-1-hydroxy-2-nitroethyl-phosphonates and 1-hydroxy-1-(nitromethyl)alkylphosphonates was prepared by nucleophilic addition of nitromethane to dialkyl acylphosphonates in the presence of potassium carbonate and tetrabutylammonium bromide.
Mechanism of the Reaction of Trialkyl Phosphites with α-Halogenoacetophenones in Alcoholic Solvents
Petnehazy, Imre,Keglevich, Gyoergy,Toeke, Laszlo,Hudson, Harry R.
, p. 127 - 132 (2007/10/02)
Second-order rate constants and activation parameters have been determined for the reactions of trialkyl phosphites in alcoholic media with α-chloro- or α-bromo-acetophenones having various substituents in the benzene ring (3,4-Me2, 4-Me, H, 4-Cl, and 4-I).Linear Hammett plots are consistent with the involvement of a common first intermediate in the rate-determining stage, leading to the formation of vinyl phosphate, α-hydroxyphosphonate, and acetophenone.The results provide the first kinetic evidence in support of the initial formation of the previously suggested betaine as a common intermediate in alcoholic solution.Further reaction then involves rearrangement to give the vinyloxyphosphonium species (and hence the Perkow product) or protonation followed by dealkylation to give the α-hydroxyphosphonate.Evidence for the possible formation of dehalogenated ketone via solvolysis of the α-hydroxyphosphonium intermediate is also presented.
Silyl Phosphites. 16. Mechanism of the Perkow Reaction and the Kukhtin-Ramirez Reaction. Elucidation by means of a New Type of Phosphoryl Rearrangements Utilizing Silyl Phosphites
Sekine, Mitsuo,Nakajima, Masashi,Hata, Tsujiaki
, p. 4030 - 4034 (2007/10/02)
Reactions of α-lithiated diethyl α-benzylphosphonate (4) with benzoyl chloride and chloroiodomethane afforded benzoylated and chloromethylated products (1 and 2) corresponding to the 1:1 carbonyl adducts of diethyl trimethylsilyl phosphite with benzil and phenacyl chloride which were not obtained by the reactions between the phosphite and benzil or phenacyl chloride.Pyrolysis of 1 and 2 afforded 1,3,2-dioxaphosphole (6) and enol phosphate (8).On the other hand, treatment of 1 and 2 with tetrabutylammonium fluoride afforded benzoin phosphate (7)and 1,2-epoxy phosphonate (14), respectively, as the main products.These results are also discussed in connection with the mechanism of the Perkow reaction and the Kukhtin-Ramirez reaction.
