30611-20-2Relevant articles and documents
A phosphine-free, heterogeneous palladium-catalyzed atom-efficient carbonylative cross-coupling of triorganoindiums with aryl halides leading to unsymmetrical ketones
You, Shengyong,Xiao, Ruian,Liu, Haiyi,Cai, Mingzhong
, p. 13862 - 13870 (2017/11/27)
The first phosphine-free heterogeneous palladium-catalyzed carbonylative cross-coupling of aryl halides with triorganoindiums has been developed that proceeds smoothly under 1 or 2.5 atm of carbon monoxide in THF at 68 °C and provides a general and powerful tool for the synthesis of various valuable unsymmetrical ketones with high atom-economy, good yield, and recyclability of the catalyst. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
A phosphine-free, atom-efficient cross-coupling reaction of triorganoindiums with acyl chlorides catalyzed by immobilization of palladium(0) in MCM-41
Miao, Jiankang,Huang, Bin,Liu, Haiyi,Cai, Mingzhong
, p. 42570 - 42578 (2017/09/11)
The first phosphine-free heterogeneous palladium(0)-catalyzed cross-coupling of triorganoindiums with acyl chlorides has been developed that proceeds smoothly in THF at 68 °C and provides a general and powerful tool for the synthesis of various valuable aryl ketones and α,β-acetylenic ketones with high atom-economy and high yield. This phosphine-free heterogeneous palladium(0) catalyst can be easily prepared from commercially available reagents and recovered by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
Palladium complexes of heterobidentate ligands: Active catalysts for direct acylation of aryl halides with aldehydes via C(sp2)-H activation
Saikia, Kokil,Dutta, Dipak Kumar
, p. 20 - 25 (2015/08/04)
Abstract Heterobidentate P-S donor ligands [P-S = {2-(methylthio) phenyl}diphenylphosphine (a) and {2-((methylthio) methyl) phenyl}diphenylphosphine (b)], and their palladium complexes of the type [Pdη2-(P-S)Cl2] (1a, 1b) have been synthesised and characterised. Single crystal X-ray diffraction shows that in both the complexes, Pd occupies the centre of a slightly distorted square planar geometry. 1a forms a planner ring structure, whereas, the hexagonal ring of 1b bends from planarity to adjust any ring strain. Interesting differences between the complexes were observed in terms of the intermolecular forces. The catalytic activities of the synthesised complexes towards the direct acylation of aryl halides with aldehydes via C(sp2)-H activation were good to excellent. 1b shows better catalytic activity over 1a which may be attributed to the higher stability of the pentagonal ring of 1a. Aryl halides containing electron withdrawing group enhance the reaction, while electron donating substituent tend to retard the desired product formation. The difference in the bond lengths of Pd-P and Pd-S of the chelate complexes may impart hemilabile behaviour in the catalytic cycle by dissociating the weaker bond (Pd-S) to generate vacant coordination site at the metal centre and reassociate after the completion of the reaction.
A general method for the direct transformation of common tertiary amides into ketones and amines by addition of Grignard reagents
Huang, Pei-Qiang,Wang, Yu,Xiao, Kai-Jiong,Huang, Ying-Hong
, p. 4248 - 4254 (2015/06/02)
The direct transformation of amides into ketones by addition of organometallic reagents has attracted the attention of organic chemists for a long time. However limited methods are reliable for common amides and have found synthetic applications. Here we report a method featuring in situ activation of tertiary amides with triflic anhydride (Tf2O) followed by addition of Grignard reagents. The method displays a good generality in scope for both amides and Grignard reagents, and it can be viewed as the acylation of Grignard reagents using amides as stable and selective acylating agents. Moreover, this deaminative alkylation reaction provides a mild method for the N-Deacylation of amides to give free amines.
Copper-catalysed aerobic oxidation of alcohols using fluorous biphasic catalysis
Ragagnin, Gianna,Betzemeier, Bodo,Quici, Silvio,Knochel, Paul
, p. 3985 - 3991 (2007/10/03)
A copper(I) catalysed and TEMPO mediated fluorous biphasic oxidation of primary, secondary, allylic and benzylic alcohols with oxygen in the presence of a bipyridine ligand bearing perfluorinated ponytails is described. High chemoselectivities are observed in the oxidation of substituted cyclohexanols (substituted axial cyclohexanols react 6-8 times faster than the corresponding equatorial cyclohexanols).
The Direct Formation of Functionalized Alkyl(aryl)zinc Halides by Oxidative Addition of Highly Reactive Zinc with Organic Halides and Their Reactions with Acid Chlorides, α,β-Unsaturated Ketones, and Allylic, Aryl, and Vinyl Halides
Zhu, Lishan,Wehmeyer, Richard M.,Rieke, Reuben D.
, p. 1445 - 1453 (2007/10/02)
Highly reactive zinc, prepared by the lithium naphthalenide reduction of ZnCl2, readily undergoes oxidative addition to alkyl, aryl, and vinyl halides under mild conditions to generate the corresponding organozinc compounds in excellent yields.Significantly, the reaction will tolerate a spectrum of functional groups on the organic halides.Accordingly, this approach can now be used to prepare a wide variety of highly functionalized organozinc compounds.In the presence of Cu(I) salts, the organozinc compounds cross-couple with acid chlorides, conjugatively add to α,β-unsaturated ketones, and regioselectively undergo SN2' substitution reactions with allylic halides.They also cross-couple with aryl or vinyl halides with Pd(0) catalysts.
Deactivation of Triplet Phenyl Alkyl Ketones by Conjugatively Electron-Withdrawing Substituents
Wagner, Peter J.,Siebert, Elizabeth J.
, p. 7329 - 7335 (2007/10/02)
Para-cyano, -carbomethoxy, and -acyl substituents decrease the triplet reactivity of valerophenone (γ-hydrogen abstraction), whereas comparable meta substituents increase reactivity.Spectroscopic results are presented which indicate that para-(-R) substituents lower ?,?* triplet energies so much more than n,?* energies that the lowest triplets become largely ?,?* in nature.Meta-(-R) substituents do not stabilize ?,?* triplets enough to invert triplet levels.Both substitution patterns support a largely 1,4-biradical structure for the lowest ?,?* triplet of acylbenzenes.Ortho substituents show the usual steric anomalies: ortho cyano enhances valerophenone triplet reactivity by stabilizing the n,?* triplet; ortho carbomethoxy deactivates valerophenone by stabilizing the ?,?* triplet but not the n,?.*
