1129-35-7Relevant articles and documents
Copper-catalyzed cyanation of aryl iodides with α-cyanoacetates via C-CN bond activation
Zhang, Song-Lin,Huang, Lu
, p. 9963 - 9968 (2015)
A Cu(i)-catalyzed cyanation reaction of aryl iodides with α-cyanoacetates is reported herein, which uses α-cyanoacetates as the nontoxic and easy-handling CN source through copper-mediated C-CN bond cleavage. This reaction enables access to aryl nitriles with an array of functional groups on the aromatic ring in good to excellent yields.
Dependence of intramolecular dissociative electron transfer rates on driving force in Donor-Spacer-Acceptor systems
Antonello, Sabrina,Maran, Flavio
, p. 5713 - 5722 (1998)
The voltammetric reduction of a series of phenyl-substituted 4- benzoyloxy-1-methylcyclohexyl bromides has been investigated in DMF. The reduction leads to the cleavage of the C-Br bond. On a thermodynamic ground, the direct reduction of the tertiary C-Br function is easier than that of the selected benzoates by at least 0.5 V. However, since the direct reduction of bromides is affected by a large activation overpotential, the electron is first located in the benzoate moiety. The rate constant for the following exergonic intramolecular dissociative electron transfer was determined by kinetic analysis of the cyclic voltammetry curves. The intermolecular rate constants for the reaction between the radical anions of methyl benzoates and 4-tert-butyl-1-methylcyclohexyl bromide were also determined and found to correlate very well with related literature data pertaining to tert-butyl bromide. The intramolecular rate constants were found to be more sensitive to variation of driving force than the corresponding intermolecular data. This result can be attributed to a shift of the center of the π* orbital of the radical anion donor away from the acceptor moiety, the shift being larger for the most easily reduced donors. The resulting distance increase is therefore envisaged as responsible for a more rapid rate drop, compared to the intermolecular pattern, when smaller driving forces are considered.
A facile and efficient [bmim]N3 catalyzed direct oxidative esterification of arylaldehydes with alcohols
Valizadeh, Hassan,Ahmadi, Mina
, p. 1077 - 1080 (2012)
Task-specific ionic liquid, [bmim]N3 was used as an effective catalyst and reaction medium for the direct oxidative esterification of arylaldehydes with alcohols. The oxidative esterification reaction of a variety of arylaldehydes took place smoothly with some primary and secondary alcohols in [bmim]N3. Satisfactory results were obtained with arylaldehydes containing electron withdrawing groups. Tertiary alcohols did not react under these conditions.
Cyanation of aromatic/vinylic boronic acids with α-cyanoacetates
Wang, Xian-Jin,Zhang, Song-Lin
, p. 14826 - 14830 (2017)
A friendly protocol is reported to achieve cyanation of aromatic and vinylic boronic acids using nontoxic and readily available α-cyanoacetates as a cyano source under aerobic conditions. Many aryl/vinyl boronic acids (as well as some iodides and bromides) are amenable substrates to give aryl nitriles and acrylonitriles. This cyanation method provides a safe and operationally convenient alternative to traditional ones requiring toxic cyanide salts.
Copper-mediated cyanation of aryl boronic acids using benzyl cyanide
Luo, Yan,Wen, Qiaodong,Wu, Zhiyuan,Jin, Jisong,Lu, Ping,Wang, Yanguang
, p. 8400 - 8404 (2013)
An efficient copper-mediated synthesis of aryl nitriles from aryl boronic acids has been achieved using benzyl cyanide as a user-friendly cyanide source. Various aryl boronic acids underwent the reaction smoothly, affording the corresponding aryl nitriles in moderate to good yields. tert-Butyl hydroperoxide (TBHP) was found to be a critical agent facilitating the cyanation reaction.
PHOTOINDUCED ALCOHOLYSIS OF alpha , alpha , alpha -TRIBROMACETOPHENONE TO BENZOYLFORMATE.
Izawa,Ishiguro,Tomioka
, p. 1490 - 1496 (1983)
Irradiation of p-substituted alpha , alpha , alpha -tribromoacetophenones (1) in O//2-saturated alcohols (MeOH, prim. and sec. alcohols) afforded a new alcoholysis product, benzoylformate (2), in good yield (75-85%) along with benzoate and radical (reduction) products. Sensitization experiments showed that 2 was derived from the triplet excited 1. Formation of 2 as well as the decomposition rate of 1 were greatly accelerated by oxygen, presumably as a result of the involvement of the normally forbidden S//o yields T//1 transition of 1 due to the oxygen-1 charge transfer complex. Independent synthesis and reaction of possible intermediates in the photoalcoholysis of 1 leading to 2 suggested that 2 was formed from spontaneous (dark) reactions of initial photoalcoholysis product, alpha alpha -dibromo- alpha -alkoxyacetophenone.
Aromatics from pyrones: Esters of terephthalic acid and isophthalic acid from methyl coumalate
Kraus, George A.,Pollock III, Gerald R.,Beck, Christie L.,Palmer, Kyle,Winter, Arthur H.
, p. 12721 - 12725 (2013)
The Diels-Alder reaction of methyl coumalate with alkenes bearing electron-withdrawing groups provides terephthalates or isophthalates in good yields, with the regioselectivity depending on the electron-withdrawing group. The reaction of methyl coumalate with the salt of acrylic acid gave only the monoester of isophthalic acid. Density functional theory (B3LYP/6-31 + G(d,p)) computations of the energies of the competing transition states of the para-selective Diels-Alder reactions are in good agreement with experiment. The surprising regioselectivity of methyl coumalate with activated alkenes is attributed to a secondary orbital interaction between the pyrone oxygen and the dienophile LUMO, which switches the regiochemistry expected from simple frontier molecular orbital theory arguments. The Royal Society of Chemistry 2013.
Characterization of 2-aryl-1,3,4-oxadiazoles by 15N and 13C NMR spectroscopy
Nowak-Wydra, Barbara,Gierczyk, Blazej,Schroeder, Grzegorz
, p. 689 - 692 (2003)
15N NMR chemical shifts of 2-aryl-1,3,4-oxadiazoles were assigned on the basis of the 1H-15N HMBC experiment. Chemical shifts of the nitrogen and carbon atoms in the oxadiazole ring correlate with the Hammett σ-constants of substituents in the aryl ring (r2 ≥ 0.966 for N atoms). 15N NMR data are a suitable and sensitive means for characterizing long-range electronic substituent effects. Additionally, 13C NMR data for these compounds are presented. Copyright
Pd@CeO2-catalyzed cyanation of aryl iodides with K4Fe(CN)6·3H2O under visible light irradiation
Wang, Shengyu,Wang, Jianqiang,Pan, Junyi,Liu, Cheng,Gong, Xubin,Guo, Cheng
, (2021/01/12)
Cyanation of aryl iodides is still challenging work for chemical researchers because of harsh reaction conditions and toxic cyanide sources. Herein, we have developed a new protocol based on the combination of the catalyst Pd@CeO2, nontoxic cyanide source K4[Fe (CN)6]·3H2O, and driving force visible light irradiation. The reaction is operated at relatively moderate temperature (55°C) and exhibits good catalytic efficiency of product aryl nitriles (yields of 89.4%). Moreover, the catalyst Pd@CeO2 possesses good reusability with a slight loss of photocatalytic activity after five consecutive runs. The reaction system based on the above combination shows a wide range of functional group tolerance under the same conditions. Reaction conditions such as temperature, time, the component of catalyst, and solutions are optimized by studying cyanation of 1-iodo-4-nitrobenzene as model reaction. According to these results, the possible mechanism of Pd@CeO2-catalyzed cyanation of aryl iodides under visible light irradiation is proposed based on the influence of visible light on the catalyst and reactant compounds. In all, we provided an environmental and economic method for preparation of aryl nitriles from cyanation of aryl iodides based on the goal of green chemistry for sustainable development.
Recyclable and Reusable Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O System for Cyanation of Aryl Chlorides with Potassium Ferrocyanide
Cai, Mingzhong,Huang, Bin,Liu, Rong,Xu, Caifeng
, (2021/12/03)
Pd(OAc)2/XPhos–SO3Na in a mixture of poly(ethylene glycol) (PEG-400) and water is shown to be a highly efficient catalyst for the cyanation of aryl chlorides with potassium ferrocyanide. The reaction proceeded smoothly at 100 or 120?oC with K2CO3 or KOAc as base, delivering a variety of aromatic nitriles in good to excellent yields. The isolation of the crude products is facilely performed by extraction with cyclohexane and more importantly, both expensive Pd(OAc)2 and XPhos–SO3Na in PEG-400/H2O system could be easily recycled and reused at least six times without any apparent loss of catalytic efficiency. Graphical Abstract: Palladium-catalyzed cyanation of aryl chlorides with potassium ferrocyanide leading to aryl nitriles by using Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O as a highly efficient and recyclable catalytic system is described.[Figure not available: see fulltext.]
