Efficient Lewis acid-assisted Brønsted acid (LBA) catalysis in the iron-catalyzed Friedel-Crafts alkylation reaction of indoles

Jiang, Zhenyu; Wu, Jianhua; Li, Li; Chen, Xi-Huai; Lai, Guoqiao; Jiang, Jianxiong; Lü, Yixin; Xu, Li‐Wen

doi:10.2478/s11532-010-0016-0

Cited by 6 publications

(3 citation statements)

References 25 publications

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“…As shown in Figure 1, the chain structure of chlorinated polypropylene is well characterized [12], but fairly complicated, consisting of chain units with isolated chlorine atoms (83.4%) including those at the tertiary (65.9%) and secondary (17.5%) carbon, neighboring chlorine atoms (6.4%), and small amounts of chlorine methane (10.1%). During the Friedel–Crafts alkylation reaction, the chlorine at different carbons causes the formation of different carbocation and gives rise to different chain units incorporated in the PP chain of the resulting copolymer when further reacted with substituted benzene [13,14]. Since the Friedel–Crafts alkylation reaction undergoes a carbocation mechanism, the carbocation intermediate also causes alternative C–C bond cleavage besides reacting with the substituted benzene, resulting in a decrease in the molecular weight of the copolymer.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Propylene-co-Styrenic Monomer Copolymers via Arylation of Chlorinated PP and Their Compatibilization for PP/PS Blend

Liu

Zhang

et al. 2019

Polymers

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A series of propylene-co-styrenic monomer copolymers were synthesized using the Friedel–Crafts alkylation reaction between chlorinated PP and substituted benzene, and the effects of these copolymers on a PP/PS (80/20) blend were investigated by using the impact test, morphology observation, thermo- and dynamic mechanical analysis, and rheology measurements. The results showed that the compatibilization efficiency varied as the variation of the substitute on the benzene ring of the styrenic monomer unit was incorporated in the PP chain in an order of methyl > ethyl > methoxyl. The copolymers bearing a crystalline isotactic polypropylene chain sequence and rubbery propylene-co-styrene-like unit chain segments may prepossess imaginable applications, giving an example for the synthesis and applications of PP-based copolymers, initiating a new way to broaden the polyolefin-based material family.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Propylene-co-Styrenic Monomer Copolymers via Arylation of Chlorinated PP and Their Compatibilization for PP/PS Blend

Liu

Zhang

et al. 2019

Polymers

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“…To act as a Lewis acid it needs to lose a ligand, in accordance with the observation of the [FeA C H T U N G T R E N N U N G (acac) 2 ] + -1 b adduct. The analogous [FeA C H T U N G T R E N N U N G (acac) 2 ] +chalcone adduct has also been observed in the FeCl 3 /acac-catalyzed Friedel-Crafts alkylation of indoles [13].…”

mentioning

confidence: 75%

Organocatalytic versus Iron‐Assisted β‐Boration of Electron‐Deficient Olefins

Bonet¹,

Solé²,

Gulyás³

et al. 2011

Chemistry An Asian Journal

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In the light of current debates surrounding sustainable and green chemistry, iron has now become an attractive alternative to the most commonly used expensive noble metals in a number of homogenous catalytic reactions, as it is abundant, inexpensive, less toxic, and environmentally more acceptable. [1] Despite the intense interest in the homogenous catalytic applications of iron complexes, the only known examples of iron-mediated C À B bond formation are the 1,4-hydroboration of 1,3-dienes to obtain linear (E)-gdisubstituted allylboranes, [2] and the C À H activation/borylation of furans and thiophenes catalyzed by a half-sandwich iron N-heterocyclic carbene complex. [3] Consequently, we became interested in exploring the benefits of iron in the bboration of electron-deficient olefins, [4] comparing it with the known catalytic systems of copper [5] and nickel [6] complexes, and in particular with the most recently developed organocatalytic systems. [7] In this study, we focused on the bboration of a,b-unsaturated esters and imines, which are highly versatile reactions to access polyfunctionalized molecules.We started our study by exploring whether the addition of iron salts has any positive influence on the b-boration of a,b-unsaturated esters and imines with diboron reagents. Therefore, we selected bis(pinacolato)diboron (B 2 pin 2 ) as the boron source, methanol as the proton source, ethylcrotonate 1 a, and (E)-1-phenyl-N-(4-phenylbutan-2-ylidene)methanamine 1 b as the substrates for the model reactions (Scheme 1).

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“…Recently, tremendous efforts have been devoted to the synthesis of aromatic amine derivatives. Catalytic Friedel–Crafts reaction of aromatic amines with alkenes is one of the most efficient and atom-economical strategies to modify aromatic amine skeletons. − With regard to the synthesis of DCDPA, a number of catalytic systems using various catalysts have been reported. − Lately, Zhu and co-workers reported using the borate [Ph 3 C][B(C 6 F 5 ) 4 ] as a metal-free catalyst for hydroarylation of alkenes with primary, secondary, and tertiary aromatic amines (Table , entry 1). This method is applicable to a wide range of substrates and affords monoalkylated products with high ortho regioselectivity.…”

Section: Introductionmentioning

confidence: 99%

Zinc-Catalyzed Alkylation of Aromatic Amines in Continuous Flow

Zhang

Yao

et al. 2020

Org. Process Res. Dev.

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A practical approach to the synthesis of antioxidant 4,4′-dicumyldiphenylamine (DCDPA) and its derivatives by Friedel−Crafts alkylation of aromatic amines was developed under continuous flow conditions. Because of the enhanced mass and heat transfer features of the microreactor, the reaction time was significantly reduced in contrast to a batch mode. The reaction was carried out using a 1:6 v/v ethanol/Cl(CH 2 ) 2 Cl cosolvent system with ZnCl 2 as the catalyst to achieve satisfactory yields. This is an effective method for the synthesis of DCDPA and its derivatives with excellent para selectivity that has the merits of shorter reaction time, easy operation, and straightforward scale-up.

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Efficient Lewis acid-assisted Brønsted acid (LBA) catalysis in the iron-catalyzed Friedel-Crafts alkylation reaction of indoles

Cited by 6 publications

References 25 publications

Synthesis of Propylene-co-Styrenic Monomer Copolymers via Arylation of Chlorinated PP and Their Compatibilization for PP/PS Blend

Synthesis of Propylene-co-Styrenic Monomer Copolymers via Arylation of Chlorinated PP and Their Compatibilization for PP/PS Blend

Organocatalytic versus Iron‐Assisted β‐Boration of Electron‐Deficient Olefins

Zinc-Catalyzed Alkylation of Aromatic Amines in Continuous Flow

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