3769-84-4Relevant academic research and scientific papers
Palladium-catalyzed synthesis of α-aryl acetophenones from styryl ethers and aryl diazonium saltsviaregioselective Heck arylation at room temperature
Kandasamy, Jeyakumar,Lee, Yong Rok,Singh, Adesh Kumar,Venkatesh, Rapelly
supporting information, p. 7832 - 7837 (2021/09/28)
Preparation of α-aryl acetophenones from styryl ethers and aryldiazonium salts is described. The reaction is catalyzed by palladium acetate at room temperature in the absence of ligand and base. The developed method is highly attractive in terms of reaction conditions, substrate scope, functional group tolerance and yields. Synthetic applications of the present method are demonstrated by preparing α-aryl indoles and 3-aryl isocoumarin from styryl ethers.
Versatile and base-free copper-catalyzed α-arylations of aromatic ketones using diaryliodonium salts
Bouquin, Maxime,Jaroschik, Florian,Taillefer, Marc
, (2021/06/11)
A ligand and base-free copper catalyzed synthetic method for the efficient α-arylation of aromatic ketones is described. In order to avoid strong bases, ketone-derived silyl enol ethers were employed. Their reaction with diaryliodonium salts as aryl source provided the intermolecular C–C coupling displaying good functional group tolerance and requiring low catalyst loading.
Mn/Cu catalyzed addition of arylboronic acid to nitriles: Direct synthesis of arylketones
Moustafa, Dina,Sweet, Chelsea,Lim, Hyun,Calalpa, Brenda,Kaur, Parminder
, p. 3816 - 3820 (2018/09/18)
A direct and efficient synthesis of arylketones via arylboronic acid addition to nitriles in presence of inexpensive Mn/Cu catalytic system is reported. The use of non-precious Mn and Cu salts has been found to be highly advantageous both in terms of accessibility as well as cost effectiveness. A series of arylboronic acids as well as nitriles were used to synthesize a variety of symmetrical and unsymmetrical arylketones. Based on the literature studies, the reaction mechanism is anticipated to go through an aryl radical intermediate which reacted with the copper activated nitrile to give the desired arylketones after the hydrolysis of the imine intermediate.
Catalytic, regioselective, and green methods for rearrangement of 1,2-diaryl epoxides to carbonyl compounds employing metallic triflates, Br?nsted-acidic ionic liquids (ILs), and IL/microwave; experimental and computational substituent effect study on aryl versus hydrogen migration
Jamalian, Arezu,Rathman, Benjamin,Borosky, Gabriela L.,Laali, Kenneth K.
, p. 1 - 11 (2015/09/28)
The Lewis-acid catalyzed rearrangement of parent trans-stilbene oxide 1 was studied with M(OTf)3/DCM and M(OTf)3/[BMIM][BF4] (M = Bi, Al, Ga, Sc, and Yb; [BMIM] = butylmethylimidazolium) and Zn(NTf2)2, and with Bi(OTf)3/[BMIM][X] (X = NTf2, OTf, PF6, and BF4), employing 5 mol% of catalyst. Selective formation of 2,2-dipheylacetaldehyde 2 (phenyl migration product) was observed in all cases, with Bi(OTf)3 proving most efficient. The rearrangement of 1 was also effected in [BMIM][X] (X = NTf2, OTf, PF6, and BF4) without an added catalyst under microwave MW irradiation, and X = PF6 gave the highest yield and selectivity. Efficient and selective rearrangement of 1-2 was also observed with 0.1-0.3equiv. of [BMIM(SO3H)][OTf] in DCM and in [BMIM][X]. A substituent effect study was performed with a series of singly substituted 1,2-diphenyl oxiranes (with X = OMe, Me, F, CN, and NO2) with 5mol% Bi(OTf)3 in DCM and in [BMIM][NTf2]. Notable formation of ketones was observed with the NO2 and CN derivatives. Competing formation of ketones was also observed in [BMIM][PF6] under MW and under Br?nsted acid catalysis with [BMIM(SO3H)][OTf] in DCM and in [BMIM][NTf2]. The aryl versus H migration was studied computationally by DFT and MP2 methods and by including solvation effects (IEFPCM).
Catalytic, regioselective, and green methods for rearrangement of 1,2-diaryl epoxides to carbonyl compounds employing metallic triflates, Br?nsted-acidic ionic liquids (ILs), and IL/microwave; Experimental and computational substituent effect study on aryl versus hydrogen migration
Jamalian, Arezu,Rathman, Benjamin,Borosky, Gabriela L.,Laali, Kenneth K.
, p. 1 - 11 (2014/11/08)
The Lewis-acid catalyzed rearrangement of parent trans-stilbene oxide 1 was studied with M(OTf)3/DCM and M(OTf)3/[BMIM][BF 4] (M = Bi, Al, Ga, Sc, and Yb; [BMIM] = butylmethylimidazolium) and Zn(NTf2)2, and with Bi(OTf)3/[BMIM][X] (X = NTf2, OTf, PF6, and BF4), employing 5 mol% of catalyst. Selective formation of 2,2-dipheylacetaldehyde 2 (phenyl migration product) was observed in all cases, with Bi(OTf)3 proving most efficient. The rearrangement of 1 was also effected in [BMIM][X] (X = NTf 2, OTf, PF6, and BF4) without an added catalyst under microwave MW irradiation, and X = PF6 gave the highest yield and selectivity. Efficient and selective rearrangement of 1-2 was also observed with 0.1-0.3 equiv. of [BMIM(SO3H)][OTf] in DCM and in [BMIM][X]. A substituent effect study was performed with a series of singly substituted 1,2-diphenyl oxiranes (with X = OMe, Me, F, CN, and NO2) with 5 mol% Bi(OTf)3 in DCM and in [BMIM][NTf2]. Notable formation of ketones was observed with the NO2 and CN derivatives. Competing formation of ketones was also observed in [BMIM][PF6] under MW and under Br?nsted acid catalysis with [BMIM(SO3H)][OTf] in DCM and in [BMIM][NTf2]. The aryl versus H migration was studied computationally by DFT and MP2 methods and by including solvation effects (IEFPCM).
Metal-free carbon-carbon cross-couplings between the ion pairs in sulfonium tetraphenylborates
Xu, Mei-Li,Huang, Wenhua
supporting information, p. 4230 - 4232 (2014/07/22)
A series of sulfonium tetraphenylborates can be readily prepared by the metathesis of sulfonium halides with sodium tetraphenylborates. After heating at 120-150 °C, the sulfonium tetraphenylborates can smoothly undergo the cross-couplings between the tetraphenylborate anions and the sulfonium cations in the absence of a metal catalyst. For carbonylmethyl-, benzyl-, and allylsulfoniums, the corresponding carbonylmethyl-phenyl, benzyl-phenyl, and allyl-phenyl cross-coupling products can be obtained in 22-76% yields. An interionic electron-transfer mechanism for this cross-coupling reaction is proposed.
1,4-Silatropy of S-α-silylbenzyl thioesters: A convenient route to silyl enol and dienol ethers accompanied by C-C bond formation via thiocarbonyl ylides
Choi, Jinil,Imai, Eiichiro,Mihara, Masatoshi,Oderaotoshi, Yoji,Minakata, Satoshi,Komatsu, Mitsuo
, p. 6164 - 6171 (2007/10/03)
A novel convenient method for the generation of thiocarbonyl ylides from readily accessible starting materials and the first synthetic application of in situ generated ylides in the synthesis of silyl enol and dienol ethers, accompanied by C-C bond formation, is described. Under completely neutral conditions without any catalyst or additive, thermal reactions of S-α-silylbenzyl thioesters in sealed tubes at 180 °C provided silyl enol and dienol ethers in good to excellent yields with high stereoselectivities. This procedure consists of a multistep reaction in a one-pot process, i.e., 1,4-silatropy of S-α-silylbenzyl thioesters to give thiocarbonyl ylides, 1,3-electrocyclization of the ylides to give thiiranes, and the extrusion of sulfur from thiiranes to give silyl enol and dienol ethers.
A simple, user-friendly process for the homologation of aldehydes using tosylhydrazone salts
Aggarwal, Varinder K.,De Vicente, Javier,Pelotier, Beatrice,Holmes, Ian P.,Bonnert, Roger V.
, p. 10327 - 10331 (2007/10/03)
Aldehydes can be homologated to ketones in moderate to good yields using aryldiazomethanes generated in situ from tosylhydrazones. Chiral aldehydes can be employed with almost complete retention of configuration. The tosylhydrazones can also be generated in situ from the corresponding aldehyde leading to a one-pot process for coupling two different carbonyl compounds to give ketones. (C) 2000 Elsevier Science Ltd.
Iron lewis acid catalyzed reactions of phenyldiazomethane with aromatic aldehydes
Mahmood, Syed J.,Saha, Anjan K.,Mahmun Hossain
, p. 349 - 358 (2007/10/03)
The iron Lewis acid 1 was found to catalyze reactions of phenyldiazomethane and aromatic aldehydes to give cis-epoxides along with the corresponding ketones. The yield of the epoxide increased with electron- withdrawing substituents on the aldehyde, while little or no epoxide was formed with electron-donating substituents. The reaction was found to go through the coordination of the aldehyde to the iron Lewis acid instead of a carbene intermediate.
Flavonoids. 43. Deprotonation-initiated Aryl Migration with Sulfur Dioxide Extrusion: A Route to 2,3-Dihydro-2,3-diaryl-3-hydroxy-4H-1-benzopyran-4-ones
Patonay, Tamas,Hegedues, Laszlo,Patonay-Peli, Erzsebet
, p. 145 - 151 (2007/10/02)
Treatment of trans-2,3-dihydro-2-aryl-3-nosyloxy-4H-1-benzopyran-4-ones with various bases afforded 2,3-dihydro-r-2-aryl-t-3-hydroxy-c-3-(4-nitrophenyl)-4H-1-benzopyran-4-ones in a deprotonation-initiated aryl migration followed by sulfur dioxide extrusion.In the presence of hydroxide and methoxide ions a secondary ring cleavage has also been observed.However, the reaction of trans-2,3-dihydro-2-aryl-3-nosyloxy-4H-1-benzopyran-4-ones with cyanide ions gave 2,3-dihydro-r-2-aryl-t-4-cyano-c-3,c-4-epoxy-4H-1-benzopyrans in a carbonyl attack of cyanide followed by an internal substitution reaction.
