6245-96-1Relevant academic research and scientific papers
Metal-Free C-O Bond Functionalization: Catalytic Intramolecular and Intermolecular Benzylation of Arenes
Bering, Luis,Jeyakumar, Kirujan,Antonchick, Andrey P.
supporting information, p. 3911 - 3914 (2018/07/22)
A catalytic, metal-free intramolecular rearrangement of benzyl phenyl ethers using nitrosonium salt as a catalyst is described. The optimized reaction conditions enabled a catalytic and metal-free Friedel-Crafts alkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel-Crafts reaction.
From insertion to multicomponent coupling: Temperature dependent reactions of arynes with aliphatic alcohols
Thangaraj, Manikandan,Bhojgude, Sachin Suresh,Mane, Manoj V.,Biju, Akkattu T.
supporting information, p. 1665 - 1668 (2016/01/30)
The temperature dependent selectivity switch in the reaction of arynes with aliphatic alcohols in THF has been reported. At -20°C, arynes smoothly insert into the O-H bond of alcohols to form alkyl aryl ethers. Interestingly, at 60°C, a highly selective multicomponent coupling occurs with the solvent THF acting as the nucleophilic trigger affording (4-(alkoxy)butoxy)arenes.
Tetrabutyl ammonium bromide-mediated benzylation of phenols in water under mild condition
Wang, Hailei,Ma, Yuping,Tian, Heng,Yu, Ajuan,Chang, Junbiao,Wu, Yangjie
, p. 2669 - 2673 (2014/04/03)
Benzylation of phenol was successfully achieved in water under room temperature mediated by tetrabutylammonium bromide (TBAB) for only 2 h affording the corresponding benzyl phenyl ether with good to excellent yields. This protocol is very efficient, simple, avoiding catalysts, easy to work-up after reaction, and especially 'green'.
Palladium-catalyzed substitution and cross-coupling of benzylic fluorides
Blessley, George,Holden, Patrick,Walker, Matthew,Brown, John M.,Gouverneur, Veronique
supporting information; experimental part, p. 2754 - 2757 (2012/07/16)
Benzylic fluorides are suitable substrates for Pd(0)-catalyzed Tsuji-Trost substitution using carbon, nitrogen, oxygen, and sulfur nucleophiles and for cross-coupling with phenylboronic acid. For the bifunctional substrate 4-chlorobenzyl fluoride, fine-tuning of the reaction conditions allows for the regioselective displacement of either the chlorine or fluorine substituent. The leaving group ability of fluoride vs other groups displaced in substitution is CF3CO2 ≈ p-NO2C6H 4CO2 ≈ OCO2CH3 > F > CH3CO2, a ranking similar to allylic fluorides under Pd catalysis.
Benzylic C-H activation and C-O bond formation via aryl to benzylic 1,4-palladium migrations
Kesharwani, Tanay,Larock, Richard C.
, p. 6090 - 6102 (2008/09/21)
A procedure for benzylic C-H activation has been developed using a palladium 1,4-aryl to benzylic migration as a key step. Carboxylates and phenoxides readily trap the resulting benzylic palladium intermediates obtained from palladium 'through space' migration. Aryl bromides and iodides have been successfully employed in this reaction, furnishing moderate to good yields. The mechanism of this reaction has been studied by deuterium-labeling experiments, which suggest that the migration of palladium from an aryl to a benzylic position occurs reversibly. The reaction conditions developed for the migration process also oxidize the neighboring benzylic alcohols to the corresponding aldehydes and ketones.
Fragmentation of anion radicals with elimination of aryloxy groups
Dneprovskii,Fedosov
, p. 1438 - 1443 (2007/10/03)
4-Vinylbenzyl phenyl ether, 4-phenylbenzyl phenyl ether, 1- and 2-naphthylmethyl phenyl ethers react with sodium thiophenolate under photochemical stimulation with replacement of the phenoxy group. The composition of reaction products and relation of reactivity to the structure of substrates is consistent with anion-radical mechanism. The corresponding methoxy and cyano derivatives do not undergo the reaction.
Synthesis and reactivity of benzylic sulfonium salts: Benzylation of phenol and thiophenol under near-neutral conditions
Forrester,Jones,Newton,Preston
, p. 2871 - 2884 (2007/10/03)
A series of benzyldimethylsulfonium - and related hydrogensulfate salts have been synthesized from the ternary system ArCH2OH:H2SO4: Me2S or tetrahydrothiophene. The salts are generally stable crystalline solids, but anomalously high reactivity is observed for 9-(anthrylmethyl)dimethylsulfonium hydrogensulfate. Selected sulfonium salts have been used for the O- and S-benzylation of phenol and thiophenol, respectively, in a two phase system under near-neutral conditions. The benzylation of oximes and benzimidazole under basic conditions is also described.
Laser flash photolysis of 1,8-bis(substituted methyl)naphthalenes
Ouchi, Akihiko,Koga, Yoshinori,Alam, Maksudul M.,Ito, Osamu
, p. 1705 - 1710 (2007/10/03)
The transient absorption spectra obtained by the laser flash photolysis of 1,8-bis(substituted methyl)naphthalenes have been measured.By comparison with the transient spectra for 1-(substituted methyl)naphthalenes, the transient species absorbing at 430 nm observed from (PhO-CH2)2Naph is attributed to the triplet state.In the case of (PhS-CH2)2Naph, absorption bands at 490 and 430 nm due to PhS are observed in addition to an absorption band in the region of 310-400 nm, which is due to the carbon-centred radical CH2Naph(CH2-SPh)>.For (PhSe-CH2)2Naph, a new broad absorption band appeared in the region of 400-520 nm, which covered weak absorption bands due to PhSe at 430 and 490 nm.The new absorption is attributed to the carbon-centred radical CH2Naph(CH2-SePh)> in which there is considerable interaction between the CH2- and PhSe moieties.The possibility of a bridged radical for CH2Naph(CH2-SePh) is suggested by MO calculations.
Photochemistry of 1-naphthylmethyl carbonates and carbamates
Parman,Pincock,Wedge
, p. 1254 - 1261 (2007/10/02)
The photochemistry in methanol of 1-naphthylmethyl phenyl carbonate (3) and 1-naphthylmethyl benzyl carbonate (4) has been studied. Products resulting from both the 1-naphthylmethyl cation and the 1-naphthylmethyl radical are obtained for 3, but only from
Novel Synthesis of N,N-Diarylarylmethanamines from N-(Arylmethylene)arenamines and (Arylmethoxy)arenes
Paventi, Martino,Hay, Allan S.
, p. 5875 - 5882 (2007/10/02)
Various N,N-diarylarylmethanamines were synthesized by the reaction of N-(arylmethylene)arenamines with (arylmethoxy)arenes in dimethylformamide solution in the presence of a strong base as a catalyst which is obtained in situ by reacting metallic sodium with this solvent.In general, the reaction may be depicted as the reduction of the imine and addition, on the original imino nitrogen atom, of the aryl group (of the aryloxy moiety) of the ether and presumably oxidation of the arylmethoxy group of the ether to its corresponding aldehyde.Side reactions and a proposed reaction mechanism are discussed.
