6317-73-3Relevant academic research and scientific papers
Novel aluminium exchanged dodecatungstophosphoric acid supported on K-10 clay as catalyst: Benzoylation of diphenyloxide with benzoic anhydride
Tiwari, Manishkumar S.,Yadav, Ganapati D.
, p. 49091 - 49100 (2016)
A series of (20% w/w) aluminium exchanged dodeca-tungstophosphoric acids (DTP) (Alx-DTP, x = 0.33-1) supported on montmorillonite K-10 clay were synthesized and completely characterized by sophisticated techniques. These catalysts were used for
Suzuki?Miyaura coupling and O?arylation reactions catalysed by palladium(II) complexes of bulky ligands bearing naphthalene core, Schiff base functionality and biarylphosphine moiety
Arora, Aayushi,Kaushal, Jolly,Kumar, Arun,Nautiyal, Divyanshu,Oswal, Preeti,Singh, Siddhant
, (2022/01/19)
Schiff bases L1 [i.e., 2-(diphenylphosphino)-N-(naphthalen-1-ylmethylene)ethanamine], L2 [i.e., 2- (diphenylphosphino)-N-(naphthalen-2-ylmethylene)ethanamine], L3 [i.e., 2-(1-(2-(diphenylphosphino)ethylim- ino)ethyl)naphthalen-1-ol] and L4 [i.e., 2-((2-(diphenylphosphino)ethylimino)methyl)naphthalen-1-ol] have been synthesized using a straightforward methodology which involves a condensation reaction between H2N?CH2?CH2?PPh2 and appropriate carbonyl compound. Due to the presence of diphenylphosphine (?PPh2) moiety and >C = N? functionality, these compounds behave as ligands and undergo complexation reaction with palladium on treatment with Na2PdCl4 to yield the palladium(II) complexes (1–4). Ligands as well as complexes have been characterized using standard NMR spectroscopic techniques. ESI?MS and single crystal X?ray diffraction studies corroborate the structures of complexes. Crystal structures of complexes 1?3 reveal clearly that the geometry around Pd centre is distorted square planar. Ligands L1 and L2 are coordinated to Pd centre in bidentate (P, N type) mode, however, L3 and L4 act as a tridentate (P,N,O type) ligand and bind with metal in anionic mode. The Pd P and Pd N bond distances in complexes 1?3 are in the ranges 2.204?2.212 ? and 2.023?2.072 ?, respectively. Complex 3 [i.e., PdCl(L3?H)] also has a Pd-O bond, the length of which is found to be 2.009(3) ?. All the complexes have potential for catalysing O-arylation (C-O coupling) of phenol and Suzuki-Miyaura coupling (SMC) reactions. Both bromoarenes and chloroarenes can be used as substrates in Suzuki coupling and converted into biaryl derivatives. For O-arylation reactions of phenol, bromoarenes are used as arylating agents. For catalysis of such reactions (i.e., C-O coupling), high (0.1 mol%) catalyst loading is required. However, Suzuki reactions require low (0.001 mol%) loading of catalysts to occur with bromoarenes and give the products. The high potential of the complexes is also evident from the fact that they also convert different aryl chlorides into the coupled products in Suzuki coupling. 31P{1H} NMR data reveal that the electronic environments of nuclei of phosphorous donors are closely similar in all the four ligands. Similar magnitude of deshielding of the 31P{1H} signals in all the complexes indicate that, while forming the dative bond, the P donor of all the ligands transfer the electron density to the palladium to a similar extent. Hence, the electronic effects created by the ligands through the phosphorous donor are similar in all the complexes. Therefore, it is inferred that variation in their catalytic performance is because of difference in the binding mode of the ligand and/or minor alteration in the architecture of organic ligand. Amongst them, complex 2 shows the highest catalytic activity, and the least active catalyst is complex 3 for C-C coupling reactions. For C-O coupling reactions, the efficiencies of complexes 1 and 2 are slightly higher than those of complexes 3 and 4.
Enantioselective Synthesis of Bicyclopentane-Containing Alcohols via Asymmetric Transfer Hydrogenation
Vyas, Vijyesh K.,Clarkson, Guy J.,Wills, Martin
supporting information, p. 3179 - 3183 (2021/05/04)
Compounds a containing bicyclo[1.1.1]pentane (BCP) adjacent to a chiral center can be prepared with high enantiomeric excess through asymmetric transfer hydrogenation (ATH) of adjacent ketones. In the reduction step, the BCP occupies the position distant from the η6-arene of the catalyst. The reduction was applied to the synthesis of a BCP analogue of the antihistamine drug neobenodine.
Synthesis of diaryl ketones through oxidative cleavage of the C-C double bonds in N -Sulfonyl enamides
Kim, Hyunseok,Park, Sangjune,Baek, Yonghyeon,Um, Kyusik,Han, Gi Uk,Jeon, Da-Hye,Han, Sang Hoon,Lee, Phil Ho
, p. 3486 - 3496 (2018/04/14)
An oxidative cleavage of a C-C double bond is developed from the photochemical [2+2]-cycloaddition of diaryl N-tosyl enamides, aryl heteroaryl N-tosyl enamides, and N-tosyl cyclic enamides with singlet molecular oxygen, followed by a ring-opening reaction mediated by Cs2CO3 under air and sunlight without the use of photosesitizer, producing symmetrical and unsymmetrical diaryl, heterodiaryl, and cyclic ketones in good to excellent yields. Moreover, the oxidative cleavage of C-C triple bonds from 1-alkynes is demonstrated for the synthesis of symmetrical and unsymmetrical ketones from the Cu-catalyzed [3+2]-cycloaddition, Rh-catalyzed alkoxyarylation, photooxygenation, and ring-opening reaction in one-pot. Because the synthesis of the symmetrical and unsymmetrical diaryl and/or heterodiaryl ketones bearing an electron-donating group is not easy, the present method is notable.
Exploring Tandem Ruthenium-Catalyzed Hydrogen Transfer and SNAr Chemistry
Polidano, Kurt,Reed-Berendt, Benjamin G.,Basset, Ana?s,Watson, Andrew J. A.,Williams, Jonathan M. J.,Morrill, Louis C.
supporting information, p. 6716 - 6719 (2017/12/26)
A hydrogen-transfer strategy for the catalytic functionalization of benzylic alcohols via electronic arene activation, accessing a diverse range of bespoke diaryl ethers and aryl amines in excellent isolated yields (38 examples, 70% average yield), is reported. Taking advantage of the hydrogen-transfer approach, the oxidation level of the functionalized products can be selected by judicious choice of simple and inexpensive additives.
Method for synthesizing aromatic aldehyde, aromatic ketone and aromatic ester through catalytically oxidizing alkyl aromatic compound by iron
-
Paragraph 0062; 0063, (2017/10/13)
The invention discloses a method for synthesizing aromatic aldehyde, aromatic ketone and aromatic ester through catalytically oxidizing an alkyl aromatic compound by iron, and belongs to the technical field of catalytic synthesis. According to the method, a low-cost and environment-friendly iron catalyst is used under a normal pressure; under the action of hydrogen and silicon reagents serving as an accelerant and an oxidant, a side chain of an aromatic hydrocarbon is oxidized into a carbonyl group for generating the corresponding aromatic aldehyde, aromatic ketone and aromatic ester. The method for preparing the aromatic aldehyde, the aromatic ketone and the aromatic ester through a catalytic oxidation reaction, which is provided by the invention, has numerous advantages that a catalyst, reaction raw materials, the oxidant and a silicon reagent are wide in sources and good in stability and is low-cost and environment-friendly; the alkyl aromatic compound is metered to participate in a reaction; the reaction condition is mild; the compatibility of functional groups is good; the scope of application is wide; the reaction selectivity is good; in an optimized reaction condition, the separation yield of a target product can be up to approximately 95 percent.
One pot synthesis of unsymmetrical ketones from carboxylic and boronic acids via PyClU-mediated acylative Suzuki coupling
Garcia-Barrantes, Pedro M.,McGowan, Kevin,Ingram, Steven W.,Lindsley, Craig W.
, p. 898 - 901 (2017/02/10)
A synthetic procedure for the preparation of ketones from easily accessible carboxylic acids has been developed. This methodology proceeds via in situ activation of the carboxylic acid with PyClU, followed by the palladium-catalyzed acylative cross-coupling with boronic acids. The reaction is performed in one pot, without the need of phosphine ligands, at room temperature and in reaction times of 2 h or less. The scope of the reaction is robust with aryl boronic and carboxylic acids.
Highly efficient heterogeneous copper-catalysed O-arylation of phenols by nitroarenes leading to diaryl ethers
Du, Yingying,Yao, Fang,Tuo, Yuxin,Cai, Mingzhong
, p. 725 - 729 (2018/01/08)
The heterogeneous O-arylation of phenols by nitroarenes was achieved in DMF at 100 °C by using an MCM-41-immobilised bidentate nitrogen copper(II) complex [MCM-41-2N-Cu(OAc)2] as catalyst, yielding a variety of unsymmetrical diaryl ethers in good to excellent yields. This heterogeneous copper catalyst can be easily prepared by a simple procedure from commercially readily available and inexpensive reagents, recovered by filtration of the reaction solution and recycled at least seven times without significant loss of activity.
A counteranion triggered arylation strategy using diaryliodonium fluorides
Chan,McNally,Toh,Mendoza,Gaunt
, p. 1277 - 1281 (2015/02/05)
A mild and transition metal-free counteranion triggered arylation strategy has been developed using diaryliodonium fluorides. The fluoride counteranion within the hypervalent iodonium species displays unusual reactivity that activates a phenolic O-H bond leading to electrophilic O-arylation. A wide range of phenols and diaryliodonium salts are compatible with this transformation under remarkably mild conditions. Furthermore, we pre-empt the wider implications of this strategy by demonstrating the compatibility of the arylation tactic with latent carbon nucleophiles.
Ion-pairing of phosphonium salts in solution: C-H...halogen and C-H...π hydrogen bonds
Ammer, Johannes,Nolte, Christoph,Karaghiosoff, Konstantin,Thallmair, Sebastian,Mayer, Peter,Devivie-Riedle, Regina,Mayr, Herbert
supporting information, p. 14612 - 14630 (2013/11/06)
The 1HNMR chemical shifts of the C(α)-H protons of arylmethyl triphenylphosphonium ions in CD2Cl2 solution strongly depend on the counteranions X-. The values for the benzhydryl derivatives Ph2CH-PPh3+ X -, for example, range from δH=8.25 (X -=Cl-) over 6.23 (X-=BF4 -) to 5.72ppm (X-=BPh4-). Similar, albeit weaker, counterion-induced shifts are observed for the ortho-protons of all aryl groups. Concentration-dependent NMR studies show that the large shifts result from the deshielding of the protons by the anions, which decreases in the order Cl- > Br- a‰ BF4 - > SbF6-. For the less bulky derivatives PhCH2-PPh3+ X-, we also find C-H...Ph interactions between C(α)-H and a phenyl group of the BPh4- anion, which result in upfield NMR chemical shifts of the C(α)-H protons. These interactions could also be observed in crystals of (p-CF3-C6H4)CH2-PPh 3+ BPh4-. However, the dominant effects causing the counterion-induced shifts in the NMR spectra are the C-H...X- hydrogen bonds between the phosphonium ion and anions, in particular Cl- or Br-. This observation contradicts earlier interpretations which assigned these shifts predominantly to the ring current of the BPh4- anions. The concentration dependence of the 1HNMR chemical shifts allowed us to determine the dissociation constants of the phosphonium salts in CD2Cl2 solution. The cation-anion interactions increase with the acidity of the C(α)-H protons and the basicity of the anion. The existence of C-H...X- hydrogen bonds between the cations and anions is confirmed by quantum chemical calculations of the ion pair structures, as well as by X-ray analyses of the crystals. The IR spectra of the Cl- and Br- salts in CD2Cl2 solution show strong red-shifts of the C-H stretch bands. The C-H stretch bands of the tetrafluoroborate salt PhCH 2-PPh3+ BF4- in CD 2Cl2, however, show a blue-shift compared to the corresponding BPh4- salt.
