21185-25-1Relevant academic research and scientific papers
Chemo- and stereoselectivity of the reaction of aromatic aldehydes with triphenylphosphine and trichloroacetic acid derivatives
Matveeva,Erin,Osetrov,Leshcheva,Kurts
, p. 388 - 392 (2006)
Aromatic aldehydes react with triphenylphosphine and ethyl trichloroacetate or trichloroacetonitrile to give the corresponding benzylidene dichlorides or α-chlorocinnamic acid derivatives. The chemo- and regioselectivity of these reactions depend on both the substituent in the aromatic ring and reaction conditions. The product configuration was determined on the basis of the coupling constants 2JCH and 3JCH in the 13C NMR spectra. Pleiades Publishing, Inc., 2006.
Scandium Triflate Catalyzed Nazarov Cyclization of Arylvinyl Epoxides Derived from Alkoxides and Chloro(aryl)carbenes: A Facile Access to Resveratrol-Derived Natural Products
Satish, Nagam,Sudhakar, Gangarajula
, p. 605 - 610 (2021)
The reaction of arylvinyl alkoxides with chloro(aryl)carbenes provided the corresponding arylvinyl epoxides that underwent Nazarov cyclization in a catalytic amount of scandium triflate, providing easy access to several highly substituted indenes, includi
One-pot, oxidative and selective conversion of benzylic silyl and tetrahydropyranyl ethers to gem-dichlorides using trichloroisocyanuric acid and triphenylphosphine as an efficient and neutral system
Khadem Moghaddam, Roqayeh,Aghapour, Ghasem
, p. 398 - 406 (2020/11/19)
A one-pot and oxidative method is described for the first time for the conversion of benzylic trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers to gem-dichlorides using trichloroisocyanuric acid (TCCA) and triphenylphosphine (PPh3) in neutral media. Various theses substrates containing electron withdrawing or donating groups can be efficiently converted to their corresponding gem-dichlorides in good to excellent yields. The present method shows a high degree of chemoselectivity, and due to its one-pot nature is in accordance with green chemistry.
Halogenation through Deoxygenation of Alcohols and Aldehydes
Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
supporting information, p. 3061 - 3064 (2018/05/28)
An efficient reagent system, Ph3P/XCH2CH2X (X = Cl, Br, or I), was very effective for the deoxygenative halogenation (including fluorination) of alcohols (including tertiary alcohols) and aldehydes. The easily available 1,2-dihaloethanes were used as key reagents and halogen sources. The use of (EtO)3P instead of Ph3P could also realize deoxy-halogenation, allowing for a convenient purification process, as the byproduct (EtO)3Pa?O could be removed by aqueous washing. The mild reaction conditions, wide substrate scope, and wide availability of 1,2-dihaloethanes make this protocol attractive for the synthesis of halogenated compounds.
Synthesis of Aryldihalomethanes by Denitrogenative Dihalogenation of Benzaldehyde Hydrazones
Zhao, Zhensheng,Kulkarni, Kaivalya G.,Murphy, Graham K.
, p. 2222 - 2228 (2017/07/07)
We report a denitrogenative dihalogenation reaction of phenyldiazomethanes in which the hypervalent iodine reagents PhICl2 and TolIF2 act as surrogates for elemental chlorine and fluorine. Halogen transfer from iodane to aryldiazomethane is described, as is a tandem oxidative dihalogenation reaction between iodane and hydrazone. This is the first use of non-α-stabilized diazo compounds in this reaction, which provided an efficient synthesis of aryldifluoromethane (ArCHF2) and aryldichloromethane (ArCHCl2) derivatives. (Figure presented.).
One-pot, selective and mild conversion of benzylic alcohols to gem -dichlorides using chlorodiphenylphosphine and 2,3-dichloro-5,6-dicyanobenzoquinone as a new and neutral system
Aghapour, Ghasem,Mohamadian, Samaneh
, p. 520 - 527 (2015/05/20)
A mild and one-pot conversion of benzylic alcohols to their corresponding gem-dichlorides is reported for the first time using chlorodiphenylphosphine (ClPPh2) and 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in dichloromethane under neutral conditions and at room temperature. The present method can be efficiently used for preparation of gem-dichlorides even in the presence of some other functional groups with excellent chemoselectivity.
A procedure for Appel halogenations and dehydrations using a polystyrene supported phosphine oxide
Tang, Xiaoping,An, Jie,Denton, Ross M.
, p. 799 - 802 (2014/02/14)
The conversion of a commercially available polystyrene supported phosphine oxide into synthetically useful polymeric halophosphonium salts using oxalyl chloride/bromide takes place at room temperature in 5 min and generates only CO and CO2 as by-products. The polymeric halophosphonium salts so obtained are useful reagents for Appel halogenations and other dehydrative coupling reactions. This gives rise to a simple three-step synthesis cycle for Appel and related reactions using a commercially available polymeric phosphine oxide with very simple purification and no phosphorus waste.
Rasta resin-triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions
Xia, Xuanshu,Toy, Patrick H.
supporting information, p. 1397 - 1405 (2014/07/22)
Heterogeneous polymer-supported triphenylphosphine oxides based on the rasta resin architecture have been synthesized, and applied as reagent precursors in a wide range of halogenation reactions. The rasta resin-triphenylphosphine oxides were reacted with either oxalyl chloride or oxalyl bromide to form the corresponding halophosphonium salts, and these in turn were reacted with alcohols, aldehydes, aziridines and epoxides to form halogenated products in high yields after simple purification. The polymersupported triphenylphosphine oxides formed as a byproduct during these reactions could be recovered and reused numerous times with no appreciable decrease in reactivity.
Phosphorus(V)-catalyzed deoxydichlorination reactions of aldehydes
An, Jie,Tang, Xiaoping,Moore, Joshua,Lewis, William,Denton, Ross M.
, p. 8769 - 8776 (2013/09/23)
A phosphine oxide-catalyzed conversion of aldehydes into 1,1-dichlorides is reported. The reaction proceeds via a phosphorus(V)-catalysis manifold in which phosphine oxide turnover is achieved using oxalyl chloride as a consumable reagent. The new method is applicable to a range of aldehydes and, in combination with palladium-catalyzed reductive dimerization, gives rise to a new catalytic approach to the synthesis of stilbenes and a short formal synthesis of resveratrol.
Nitrile ylide dimerization: Investigation of the carbene reactivity of nitrile ylides
Fergus, Suzanne,Eustace, Stephen J.,Hegarty, Anthony F.
, p. 4663 - 4669 (2007/10/03)
A series of novel hexaaryl diazatrienes 5 ("nitrile ylide dimers") were synthesized directly from the corresponding diaryl ketimines 12 and dichlorotoluenes 13 in a facile one-pot synthesis. The carbene character of the nitrile ylides was investigated by varying the substituents on the aromatic ring adjacent to the carbene center. The isolation of the corresponding carbene dimers as stable crystalline materials with absorption maxima (λmax) from 363 to 422 nm was shown to be promoted by the absence of strongly electron-withdrawing substituents. The crystal structures indicate that the E-isomers were isolated when phenyl, 3-methylphenyl, and 3-chlorophenyl substituents are present at the carbene carbon; the Z-isomer was isolated when the more sterically hindered 2,4,6-trimethylphenyl substituent (Mes) is present. The 1H NMR spectra of the E-isomers demonstrate the nonequivalence of the aromatic rings, in which two of the aromatic rings of the imine moiety are pseudoaxial and the remaining aromatic rings are pseudoequatorial. The reactions proceed via the intermediate nitrile ylides 1 generated by the base-promoted 1,1-elimination of HCl from the intermediate chloroimine 14. The nitrile ylide was also generated by 1,3-elimination of HCl from the imidoyl chloride 18, confirming common pathways via the nitrile ylide as the dimer products obtained from these different routes were identical. The strongly electron-withdrawing 4-nitrophenyl substituent promotes the linear carbanion character of the 1,3-dipole and no dimer is formed.
