2936-55-2Relevant academic research and scientific papers
Synergistic Activation of Amides and Hydrocarbons for Direct C(sp3)–H Acylation Enabled by Metallaphotoredox Catalysis
Baik, Mu-Hyun,Choi, Seulhui,Hong, Soon Hyeok,Lee, Geun Seok,Won, Joonghee
, p. 16933 - 16942 (2020/08/03)
The utilizations of omnipresent, thermodynamically stable amides and aliphatic C(sp3)?H bonds for various functionalizations are ongoing challenges in catalysis. In particular, the direct coupling between the two functional groups has not been realized. Here, we report the synergistic activation of the two challenging bonds, the amide C?N and unactivated aliphatic C(sp3)?H, via metallaphotoredox catalysis to directly acylate aliphatic C?H bonds utilizing amides as stable and readily accessible acyl surrogates. N-acylsuccinimides served as efficient acyl reagents for the streamlined synthesis of synthetically useful ketones from simple C(sp3)?H substrates. Detailed mechanistic investigations using both computational and experimental mechanistic studies were performed to construct a detailed and complete catalytic cycle. The origin of the superior reactivity of the N-acylsuccinimides over other more reactive acyl sources such as acyl chlorides was found to be an uncommon reaction pathway which commences with C?H activation prior to oxidative addition of the acyl substrate.
Iron-Catalyzed Ortho C-H Methylation of Aromatics Bearing a Simple Carbonyl Group with Methylaluminum and Tridentate Phosphine Ligand
Shang, Rui,Ilies, Laurean,Nakamura, Eiichi
supporting information, p. 10132 - 10135 (2016/08/31)
Iron-catalyzed C-H functionalization of aromatics has attracted widespread attention from chemists in recent years, while the requirement of an elaborate directing group on the substrate has so far hampered the use of simple aromatic carbonyl compounds such as benzoic acid and ketones, much reducing its synthetic utility. We describe here a combination of a mildly reactive methylaluminum reagent and a new tridentate phosphine ligand for metal catalysis, 4-(bis(2-(diphenylphosphanyl)phenyl)phosphanyl)-N,N-dimethylaniline (Me2N-TP), that allows us to convert an ortho C-H bond to a C-CH3 bond in aromatics and heteroaromatics bearing simple carbonyl groups under mild oxidative conditions. The reaction is powerful enough to methylate all four ortho C-H bonds in benzophenone. The reaction tolerates a variety of functional groups, such as boronic ester, halide, sulfide, heterocycles, and enolizable ketones.
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.
Acylative Suzuki coupling of amides: Acyl-nitrogen activation via synergy of independently modifiable activating groups
Li, Xijing,Zou, Gang
supporting information, p. 5089 - 5092 (2015/03/30)
A highly efficient palladium-catalyzed acylative cross-coupling of carboxylic amides with arylboronic acids has been achieved via synergistic activation of the Cacyl-N bond by independently modifiable activating groups. Coupling of amides features not only good functional group tolerance but also modifiable reactivities to overcome steric hindrance. This journal is
Fe-catalyzed regiodivergent [1,2]-shift of α-aryl aldehydes
Gutierrez-Bonet, Alvaro,Flores-Gaspar, Areli,Martin, Ruben
, p. 12576 - 12579 (2013/09/23)
An Fe-catalyzed conversion of aldehydes to ketones via [1,2]-shift has been developed. This skeletal rearrangement shows a wide substrate scope and chemoselectivity profile while exhibiting an excellent [1,2]-aryl or [1,2]-alkyl shift selectivity that is easily switched by electronic effects.
Friedel-Crafts acylation reaction using carboxylic acids as acylating agents
Kawamura, Masato,Cui, Dong-Mei,Shimada, Shigeru
, p. 9201 - 9209 (2007/10/03)
Dehydrative Friedel-Crafts acylation reaction of aromatic compounds with carboxylic acids as acylating agents was investigated in the presence of Lewis acid- or Br?nsted acid-catalyst. Various metal triflates and bis(trifluoromethanesulfonyl)amides showed catalytic activity at high temperature, among which Eu(NTf2)3 proved to be the most effective and efficiently catalyzed the acylation reaction of alkyl- and alkoxybenzenes with aliphatic and aromatic carboxylic acids at 250 °C. Bi(NTf2)3 was more effective than Eu(NTf2)3 at lower temperature, but proved to be hydrolyzed in the presence of a small amount of water to give HNTf2 and [Bi6O4(OH)4(H2O)6](NTf2)6. The structure of the latter compound was confirmed by a single crystal X-ray analysis. Among five Br?nsted acids, HOTf, HNTf2, HCTf3, TsOH, and Nafion SAC-13, HNTf2 has proved to be the most efficient catalyst and more effective than Eu(NTf2)3 for the acylation of p-xylene with heptanoic acid at 220 °C or lower temperature. HNTf2 catalyzed the acylation of anisole with carboxylic acids in high yields in refluxing toluene with azeotropic removal of water.
Friedel-Crafts Acylation of Arenes Catalysed by Bromopentacarbonylrhenium(I)
Kusama, Hiroyuki,Narasaka, Koichi
, p. 2379 - 2384 (2007/10/03)
The intermolecular Friedel-Crafts acylation of aromatic compounds (such as toluene, m-xylene, and anisole) with various acid chlorides proceeds by using a catalytic amount of bromopentacarbonylrhenium(I) to afford aryl ketones.Intramolecular acylation is also catalyzed by the above-mentioned catalyst to give indanone and tetralone derivatives.
Ruthenium Complex Catalyzed Intermolecular Hydroacylation and Transhydroformylation of Olefins with Aldehydes
Kondo, Teruyuki,Akazome, Motohiro,Tsuji, Yasushi,Watanabe, Yoshihisa
, p. 1286 - 1291 (2007/10/02)
Low-valent ruthenium complexes such as dodecacarbonyltriruthenium (Ru3(CO)12), (η4-1,5-cyclooctadiene)(η6-1,3,5-cyclooctatriene)ruthenium (Ru(COD)(COT)) and bis(η5-cyclooctadienyl)ruthenium showed high catalytic activity for the intermolecular hydroacylation of olefins with various aromatic and heteroaromatic aldehydes at 180-200 deg C for 24-48 h under an initial carbon monoxide pressure of 20 kg cm-2 to give unsymmetric ketones in moderate to good yields.In the reaction of 2-thiophenecarbaldehyde with cyclohexene, cyclohexyl 2-thienyl ketone was obtained in 62 percent yield.On the other hand, when the aliphatic aldehyde, heptanal, was treated with cyclohexene, the corresponding ketone was not obtained at all, and a transhydroformylation reaction proceeded; i.e., the formyl group of heptanal was apparently transformed to cyclohexene to give cyclohexanecarbaldehyde in 29 percent yield, together with their Tishchenko-type reaction products.
