55363-57-0Relevant academic research and scientific papers
Heterogeneous Suzuki-Miyaura coupling of heteroaryl ester: Via chemoselective C(acyl)-O bond activation
Ma, Hongpeng,Bai, Chaolumen,Bao, Yong-Sheng
, p. 17266 - 17272 (2019/06/24)
A site-selective supported palladium nanoparticle catalyzed Suzuki-Miyaura cross-coupling reaction with heteroaryl esters and arylboronic acids as coupling partners was developed. This methodology provides a heterogeneous catalytic route for aryl ketone formation via C(acyl)-O bond activation of esters by successful suppression of the undesired decarbonylation phenomenon. The catalyst can be reused and shows high activity after eight cycles. The XPS analysis of the catalyst before and after the reaction suggested that the reaction might be performed via a Pd0/PdII catalytic cycle that began with Pd0.
Acid fluorides as acyl electrophiles in suzuki–miyaura coupling
Ogiwara, Yohei,Sakino, Daisuke,Sakurai, Yuka,Sakai, Norio
supporting information, p. 4324 - 4327 (2018/08/28)
The first palladium-catalyzed construction of ketones through Suzuki–Miyaura reaction by using acid fluorides is described. In contrast to typical acyl electrophiles such as acid chlorides, acid fluorides are uncommon acyl electrophiles to use in boron-based coupling reactions, probably due to a high level of stability toward nucleophiles. This first attempt to use acid fluorides as a coupling partner with boronic acids allowed highly functional group tolerance and a wide substrate scope while affording various ketones in effective yields.
Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule
Kulasekharan, Revathy,Maddipatla, Murthy V. S. N.,Parthasarathy, Anand,Ramamurthy
, p. 942 - 949 (2013/04/10)
Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10-8 s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.
Palladium-catalyzed and copper-mediated cross-coupling reaction of aryl- or alkenylboronic acids with acid chlorides under neutral conditions: Efficient synthetic methods for diaryl ketones and chalcones at room temperature
Ogawa, Daisuke,Hyodo, Keita,Suetsugu, Masato,Li, Jing,Inoue, Yoshiaki,Fujisawa, Mamoru,Iwasaki, Masayuki,Takagi, Kentaro,Nishihara, Yasushi
, p. 2565 - 2571 (2013/03/28)
Palladium-catalyzed cross-coupling reaction of aryl- or alkenylboronic acids with acid chlorides in the presence of copper(I) thiophene-2-carboxylate (CuTC) as an activator in diethyl ether at room temperature under strictly non-basic conditions affords the diaryl ketones or chalcones in moderate to excellent yields. A wide range of substrates bearing an electron-donating or an electron-withdrawing substituent on the aromatic ring are compatible.
Room-temperature palladium-catalyzed and copper(I)-mediated coupling reactions of acid chlorides with boronic acids under neutral conditions
Nishihara, Yasushi,Inoue, Yoshiaki,Fujisawa, Mamoru,Takagi, Kentaro
, p. 2309 - 2312 (2007/10/03)
The palladium-catalyzed cross-coupling reactions of acid chlorides with arylboronic acids in the presence of copper(I) thiophene-2-carboxylate (CuTC) as an activator under strictly non-basic and mild reaction conditions afford the unsymmetrical ketones in moderate to excellent yields. A wide range of substrates bearing an electron-donating or an electron-withdrawing substituent on the aromatic ring is compatible. Georg Thieme Verlag Stuttgart.
Tetraphosphine/palladium catalysed Suzuki cross-coupling reactions of aryl halides with alkylboronic acids
Kondolff, Isabelle,Doucet, Henri,Santelli, Maurice
, p. 3813 - 3818 (2007/10/03)
Through the use of [PdCl(C3H5)]2/cis,cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides and chlorides undergoes Suzuki cross-coupling with alkylboronic acids in good yields. Several alkyl substituents such as ethyl, n-butyl, n-octyl, isobutyl or 2,2-dimethylpropyl on the alkylboronic acids have been successfully used. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides.
A comparative product investigation between Grignard reactions of benzophenone and coupling reactions of electrogenerated benzophenone radical anions and alkyl radicals in THF
Lund, Torben,Ohlrich, Ditte,Borling, Pernille
, p. 932 - 937 (2007/10/03)
The 1,6-to 1,2-addition product ratios of the Grignard reactions of benzophenone with t-, s- and n-C4H9MgCl have been compared with the corresponding ratios obtained by the electrolysis of benzophenone in presence of t-, s- and n-C4H9S+(CH3)2, ClO4-in THF. The Grignard reaction ratios 0.81, 0.50 and 0.19, respectively, were obtained whereas the corresponding electrolysis ratios were 2.26, 1.23 and 1.61. From this comparison of product ratios it is concluded that none of the Grignard reactions of benzophenone proceeds through a complete free coupling process of benzophenone radical anions and butyl radicals. The ET character of the Grignard reactions of benzophenone with t-, s- and n-C4H9MgCl was estimated to be 65, 61 and 26%, respectively.
Influence of Solvent and Cation on the Properties of Oxygen-containing Organic Anions. Part 4. Mechanism and Reactivity of Tetraaryloxirane Cleavage with Alkali Metals
Franco, M. Luisa T. M. B.,Herold, Bernardo J.,Maercker, Adalbert
, p. 119 - 129 (2007/10/02)
Six tetraaryloxiranes 1a-f (Scheme 4) were reduced (Schemes 1-3) with alkali metals (M = Li, Na, K, Cs) in eight polar aprotic solvents under an inert atmosphere.The organometallic solutions thus obtained were hydrolysed and the reaction products analysed.Similar experiments were carried out where the same solutions were quenched with D2O or MeI.In some cases the same solutions were studied by NMR and ESR spectroscopy before quenching.A stepwise reduction mechanism was established where the transfer of a first electron produces CO-bond scission in the oxirane ring, yielding a short-lived radical anion 4 or 5 (Scheme 1), i. e., a tetraalkyl-β-oxidoethyl radical.This intermediate can either eliminate oxygen as metal oxide (MO) to produce a tetraarylethylene 24 (Scheme 2) or be further reduced to a dianion 8 or 9 (Scheme 1).This anion yields, upon hydrolysis, low yields,if any, of the corresponding tetraphenylethanol 15 or 16 (Z = H).The larger proportion of the dianion, after the first protonation step, yielding anion 11 or 22, undergoes CC-bond scission which leads eventually to the corresponding ketone and diarylmethane 19 + 20 or 21 + 23 (Z = H) (Scheme 2).Other possible pathways were excluded through experiments where other possible intermediates were generated.These led to different end products.A triparametric linear correlation as a function of solvent parameters ETN and DN, as well as the cationic radius, was established for the influence of the nature of the solvent and counter-ion on the ratio between the rates of formation of products stemming from metal oxide (MO) elimination by the ring-opened radical anion 4 or 5 (Schemes 1 and 2) and rates of formation of products stemming from further reduction of the same radical anion to the dianion 8 or 9, thus confirming the mechanism established.
Norrish Type I and Type II Reactions of Ketones as Photochemical Probes of the Interior of Zeolites
Ramamurthy, V.,Corbin, D. R.,Eaton, D. F.
, p. 5269 - 5278 (2007/10/02)
The Norrish type I and type II reactions of alkylbenzoin ethers, alkyldeoxybenzoins and α-alkyldibenzyl ketones included within the microporous structures of zeolites X and Y have been investigated.Product distributions varied significantly from that observed in benzene.In addition, it differed between various alkali-metal cation-exchanged samples.These variations are interpreted to result from the restriction offered by the zeolite micropores on the motions of the adsorbed organic molecule.Although this study is restricted to ketones, the knowledge gained is expected to be of general value.
