13365-62-3Relevant academic research and scientific papers
An Effective Osmium Precatalyst for Practical Synthesis of Diarylketones: Preparation, Reactivity, and Catalytic Application of [OsH- cis-(CO)2- mer-{κ3- P, B, P′-B(NCH2PPh2)2- o-C6H4}]
Chang, Jiarui,Chen, Xuenian,Fang, Fei,Zhang, Jie
supporting information, p. 3825 - 3832 (2021/11/18)
Developing new approaches for efficient synthesis of diarylketones from commercially available inexpensive substrates via practical procedures is highly desirable. In this work, an effective catalytic system for the synthesis of diarylketones was developed based on a newly synthesized Os PBP pincer complex [OsH-cis-(CO)2-mer-{κ3-P,B,P′-B(NCH2PPh2)2-o-C6H4}] (1). Complex 1 proved to be very stable against many reagents at room temperature; CS2 can only react with 1 at elevated temperatures to produce [Os(κ2-S,S'-S2CH)(CO)-mer-{κ3-P,B,P′-B(NCH2PPh2)2-o-C6H4}] (2). Complex 1 was found to be an efficient precatalyst for the coupling reactions between arylboronic acids and aryl aldehydes. The reactions are tolerant of many functional groups and proceed smoothly in toluene in the presence of K3PO4 and H2O at 100 °C under an air atmosphere to give diaryl ketones in good to excellent yields. It was demonstrated that the reactions were catalyzed by in situ generated osmium nanoparticles. This work would open an avenue of heterogeneous transition metal catalyst system for the synthesis of diarylketones via the coupling reactions between arylboronic acids and aryl aldehydes, which has never been reported before.
Evaluation of Cyclic Amides as Activating Groups in N-C Bond Cross-Coupling: Discovery of N-Acyl-δ-valerolactams as Effective Twisted Amide Precursors for Cross-Coupling Reactions
Bisz, Elwira,Chen, Hao,Dziuk, B?a?ej,Ejsmont, Krzysztof,Lalancette, Roger,Pyle, Daniel J.,Rahman, Md. Mahbubur,Szostak, Michal,Szostak, Roman,Wang, Qi
, p. 10455 - 10466 (2021/07/31)
The development of efficient methods for facilitating N-C(O) bond activation in amides is an important objective in organic synthesis that permits the manipulation of the traditionally unreactive amide bonds. Herein, we report a comparative evaluation of a series of cyclic amides as activating groups in amide N-C(O) bond cross-coupling. Evaluation of N-acyl-imides, N-acyl-lactams, and N-acyl-oxazolidinones bearing five- and six-membered rings using Pd(II)-NHC and Pd-phosphine systems reveals the relative reactivity order of N-activating groups in Suzuki-Miyaura cross-coupling. The reactivity of activated phenolic esters and thioesters is evaluated for comparison in O-C(O) and S-C(O) cross-coupling under the same reaction conditions. Most notably, the study reveals N-acyl-δ-valerolactams as a highly effective class of mono-N-acyl-activated amide precursors in cross-coupling. The X-ray structure of the model N-acyl-δ-valerolactam is characterized by an additive Winkler-Dunitz distortion parameter ?(τ+χN) of 54.0°, placing this amide in a medium distortion range of twisted amides. Computational studies provide insight into the structural and energetic parameters of the amide bond, including amidic resonance, N/O-protonation aptitude, and the rotational barrier around the N-C(O) axis. This class of N-acyl-lactams will be a valuable addition to the growing portfolio of amide electrophiles for cross-coupling reactions by acyl-metal intermediates.
Highly efficient synthesis of aryl ketones by PEPPSI-palladium catalyzed acylative Suzuki coupling of amides with diarylborinic acids
Wang, Chen,Huang, Lingyun,Wang, Fengze,Zou, Gang
supporting information, p. 2299 - 2301 (2018/05/16)
An improved acylative cross-coupling of various N-methyl-N-tosyl amides with diarylborinic acids for synthesis of aryl ketones is developed. In most cases, aryl ketones could be obtained in excellent yields by using 1 mol% 2,6-diisopropylphenylimidazolylidene and 3-chloropyridine co-supported palladium chloride as catalyst in the presence of 3 equiv. K2CO3 as base in refluxing THF. The readily prepared and cost-effective substrates, N-methyl-N-tosylamides and diarylborinic acids, and the commercially available catalyst system promise a practical and efficient access to aryl ketones.
A general approach to intermolecular carbonylation of arene C-H bonds to ketones through catalytic aroyl triflate formation
Kinney, R. Garrison,Tjutrins, Jevgenijs,Torres, Gerardo M.,Liu, Nina Jiabao,Kulkarni, Omkar,Arndtsen, Bruce A.
, p. 193 - 199 (2018/02/06)
The development of metal-catalysed methods to functionalize inert C-H bonds has become a dominant research theme in the past decade as an approach to efficient synthesis. However, the incorporation of carbon monoxide into such reactions to form valuable ketones has to date proved a challenge, despite its potential as a straightforward and green alternative to Friedel-Crafts reactions. Here we describe a new approach to palladium-catalysed C-H bond functionalization in which carbon monoxide is used to drive the generation of high-energy electrophiles. This offers a method to couple the useful features of metal-catalysed C-H functionalization (stable and available reagents) and electrophilic acylations (broad scope and selectivity), and synthesize ketones simply from aryl iodides, CO and arenes. Notably, the reaction proceeds in an intermolecular fashion, without directing groups and at very low palladium-catalyst loadings. Mechanistic studies show that the reaction proceeds through the catalytic build-up of potent aroyl triflate electrophiles.
Palladium-Catalyzed Denitrogenative Synthesis of Aryl Ketones from Arylhydrazines and Nitriles Using O2 as Sole Oxidant
Wang, Xu,Huang, Yubing,Xu, Yanli,Tang, Xiaodong,Wu, Wanqing,Jiang, Huanfeng
, p. 2211 - 2218 (2017/02/26)
An efficient and simple palladium-catalyzed approach for the synthesis of aryl ketones from low-cost nitriles and arylhydrazines using molecular oxygen (O2) as sole oxidant via C-N bond cleavage is reported. Various aryl ketones were synthesized in moderate to good yields under mild conditions. A possible mechanism involving the PdII/Pd0 catalytic cycle process is depicted, and a cationic palladium intermediate was detected by ESI-MS.
Room-Temperature Decarboxylative Couplings of α-Oxocarboxylates with Aryl Halides by Merging Photoredox with Palladium Catalysis
Cheng, Wan-Min,Shang, Rui,Yu, Hai-Zhu,Fu, Yao
supporting information, p. 13191 - 13195 (2015/09/15)
Enabled by merging iridium photoredox catalysis and palladium catalysis, α-oxocarboxylate salts can be decarboxylatively coupled with aryl halides to generate aromatic ketones and amides at room temperature. DFT calculations suggest that this reaction proceeds through a Pd0-PdII-PdIII pathway, in which the PdIII intermediate is responsible for reoxidizing IrII to complete the IrIII-IrIII-IrII photoredox cycle. Like a mergin': Enabled by merging iridium photoredox catalysis and palladium catalysis, palladium-catalyzed decarboxylative coupling of α-oxocarboxylates with aryl halides can proceed at room temperature. DFT calculations suggest that a Pd0-PdII-PdIII catalytic cycle is merged with an IrIII-IrIII-IrII photoredox cycle, in which PdIII is responsible for oxidizing IrII to complete the photoredox cycle.
Palladium-catalyzed acylative cross-coupling of amides with diarylborinic acids and sodium tetraarylborates
Li, Xijing,Zou, Gang
, p. 136 - 145 (2015/07/27)
Abstract A general and efficient acylative Suzuki coupling of active amides with diarylborinic acids has been achieved by using 1 mol% Pd(PCy3)2Cl2/0.6 mol% PCy3 as catalyst system taking advantage of modifiable reactivities of acyl-nitrogen bonds of amides. Both electronic and steric influences from either aryl or acyl counterparts on the coupling proved to be negligible or small. A variety of aryl ketones including sterically hindered ones could be synthesized by the coupling of diarylborinic acids in good to excellent yields. Sodium tetraarylborates could also be used as high atom-economy aryl source in the palladium-catalyzed cross-coupling with active amides.
Palladium(II)-catalyzed desulfitative synthesis of aryl ketones from sodium arylsulfinates and nitriles: Scope, limitations, and mechanistic studies
Skillinghaug, Bobo,Sk?ld, Christian,Rydfjord, Jonas,Svensson, Fredrik,Behrends, Malte,S?vmarker, Jonas,Sj?berg, Per J. R.,Larhed, Mats
, p. 12018 - 12032 (2015/01/16)
A fast and efficient protocol for the palladium(II)-catalyzed production of aryl ketones from sodium arylsulfinates and various organic nitriles under controlled microwave irradiation has been developed. The wide scope of the reaction has been demonstrated by combining 14 sodium arylsulfinates and 21 nitriles to give 55 examples of aryl ketones. One additional example illustrated that, through the choice of the nitrile reactant, benzofurans are also accessible. The reaction mechanism was investigated by electrospray ionization mass spectrometry and DFT calculations. The desulfitative synthesis of aryl ketones from nitriles was also compared to the corresponding transformation starting from benzoic acids. Comparison of the energy profiles indicates that the free energy requirement for decarboxylation of 2,6-dimethoxybenzoic acid and especially benzoic acid is higher than the corresponding desulfitative process for generating the key aryl palladium intermediate. The palladium(II) intermediates detected by ESI-MS and the DFT calculations provide a detailed understanding of the catalytic cycle. (Figure Presented).
A phosphane-free, atom-efficient cross-coupling reaction of triarylbismuths with acyl chlorides catalyzed by MCM-41-immobilized palladium complex
Zhao, Hong,Yin, Lin,Cai, Mingzhong
, p. 1337 - 1345 (2013/04/10)
The first phosphane-free, heterogeneous, atom-efficient cross-coupling reaction of triarylbismuths and acyl chlorides was achieved in N-methylpyrrolidone (NMP) with Bu3N as the base at 80 °C in the presence of 1.5 mol-% MCM-41-immobilized bidentate nitrogen palladium complex [MCM-41-2N-Pd(OAc)2, MCM = mobile crystalline material] to yield a variety of unsymmetrical biaryl ketones in good to excellent yields. This heterogeneous palladium catalyst exhibited a high activity, which was similar to that of Pd(PPh3)4. The catalyst can be recovered by a simple filtration of the reaction solution and recycled in at least 10 consecutive trials without any decrease in activity. Our system not only avoids the use of phosphane ligands, but also solves the basic problem of palladium catalyst recovery and reuse. The first phosphane-free, heterogeneous, atom-efficient cross-coupling reaction of triarylbismuth compounds and acyl chlorides was achieved in N-methylpyrrolidone with Bu3N as the base at 80 °C in the presence of 1.5 mol-% MCM-41-immobilized bidentate nitrogen palladium complex [MCM-41-2N-Pd(OAc)2] to yield a variety of unsymmetrical biaryl ketones in good to excellent yields. Copyright
Development of decarboxylative coupling processes for the synthesis of azomethines and ketones
Collet, Florence,Song, Bingrui,Rudolphi, Felix,Goossen, Lukas J.
, p. 6486 - 6501 (2011/12/05)
A bimetallic catalyst system has been developed that allows the synthesis of azomethines by a one-pot three-component decarboxylative coupling, starting from simple, nontoxic precursors, i.e. potassium α-oxo carboxylates, aryl halides and primary amines. In the presence of 15 mol-% copper/phenanthroline and 1 mol-% Pd/dppf, a wide range of valuable imines is conveniently accessible in high yields at 100 °C, an unprecedentedly low temperature for redox-neutral decarboxylative cross-coupling reactions. Hydrogenation of the azomethine products leads to secondary amines. Alternatively, they can be hydrolyzed in situ to aryl ketones. The resulting ketone synthesis via azomethine intermediates is also of interest as it gives higher yields at much lower temperatures than the direct decarboxylative coupling of α-oxo carboxylates with aryl halides. A convenient synthesis of azomethines by a one-pot three-component decarboxylative coupling, starting from potassium α-oxo carboxylates, aryl halides and primary amines is described. Combined with in situ hydrolysis, ketones are obtained. Thisamine-mediated ketone synthesis gives higher yields at lower temperatures than the direct coupling of α-oxo carboxylates. Copyright
