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Alkylation

About: Alkylation is a research topic. Over the lifetime, 29915 publications have been published within this topic receiving 464944 citations. The topic is also known as: alkylation reaction.


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Journal ArticleDOI
TL;DR: The robust cooperative cobalt(III) catalysis proved tolerant of valuable electrophilic functional groups, including hydroxyl, bromo, and iodo substituents and revealed a considerable additive effect on kinetics and on a negative non-linear-effect.
Abstract: The enantioselective cobalt(III)-catalyzed C-H alkylation was achieved through the design of a novel chiral acid. The cobalt(III)-catalyzed enantioselective C-H activation was characterized by high position-, regio- and enantio-control under exceedingly mild reaction conditions. Thereby, the robust cooperative cobalt(III) catalysis proved tolerant of valuable electrophilic functional groups, including hydroxyl, bromo, and iodo substituents. Mechanistic studies revealed a considerable additive effect on kinetics and on a negative non-linear-effect.

138 citations

Journal ArticleDOI
TL;DR: Sulfonic acid group (SO3H)-bearing amorphous carbon/mesoporous silica composites were studied for use as solid acid catalysts in this paper.
Abstract: Sulfonic acid group (SO3H)-bearing amorphous carbon/mesoporous silica composites were studied for use as solid acid catalysts. Sugar-derived amorphous carbon with SO3H cannot catalyze hydrophobic acid-catalyzed reactions, such as the dimerization of α-methylstyrene, because of the small surface area. However, SO3H-bearing sugar-derived amorphous carbon supported on mesoporous silica exhibits remarkable catalytic performance for the dimerization of α-methylstyrene. Under optimal conditions, the selectivity of the composite catalysts for unsaturated dimers exceeds 98%. Structural and reaction analyses revealed that SO3H-bearing carbon particles with large surface areas are formed in the mesopores and prevent intramolecular Friedel−Crafts alkylation, resulting in high catalytic activity.

138 citations

Journal ArticleDOI
TL;DR: Eight new iridium complexes containing anionic P,N ligands are synthesised, resulting in a highly active catalyst for the selective monoalkylation of anilines with primary alcohols, under mild reaction conditions.
Abstract: The synthesis of eight new iridium complexes containing anionic P,N ligands is described. These complexes have been investigated as catalysts for amine alkylation reactions, resulting in a highly active catalyst for the selective monoalkylation of anilines with primary alcohols, under mild reaction conditions. Nearly quantitative conversion was observed at 70 °C with a catalyst loading as low as 0.05 mol % iridium.

137 citations

Journal ArticleDOI
TL;DR: An unprecedented base-promoted deborylative alkylation of pyridine N-oxides using 1,1-diborylalkanes as alkyl sources is reported, which can serve as a powerful method for late-stage functionalization.
Abstract: Reported herein is an unprecedented base-promoted deborylative alkylation of pyridine N-oxides using 1,1-diborylalkanes as alkyl sources. The reaction proceeds efficiently for a wide range of pyridine N-oxides and 1,1-diborylalkanes with excellent regioselectivity. The utility of the developed method is demonstrated by the sequential C-H arylation and methylation of pyridine N-oxides. The reaction also can be applied for the direct introduction of a methyl group to 9-O-methylquinine N-oxide, thus it can serve as a powerful method for late-stage functionalization.

137 citations

Journal ArticleDOI
TL;DR: A novel synthetic method for spirocyclic molecules based on palladium-catalyzed intramolecular ipsoFriedel–Crafts alkylation of phenols and indoles is reported, which results in the formation of aza-spirocycles.
Abstract: Spirocyclohexadienones are recognized as versatile intermediates for complex molecule syntheses. Functionalization of the cyclohexadienone unit provides efficient and rapid access to multicyclic molecular frameworks. A number of natural product syntheses have been achieved using spirocyclohexadienones as key intermediates. The development of an innovative method for synthesizing spirocyclohexadienones is therefore in high demand because of its potential impact on synthetic organic chemistry. Dearomatization of phenols is one of the most straightforward approaches to the synthesis of spirocyclohexadienones. Among such methods, transition-metal-catalyzed intramolecular nucleophilic dearomatization of phenols has attracted recent attention. 4] Key to the success of this dearomatization process is whether the intramolecular C alkylation can be preferentially promoted over the competitive intermolecular O alkylation. We recently demonstrated that the present chemoselectivity issue was successfully controlled in a palladium-catalyzed intramolecular ipso-Friedel–Crafts allylic alkylation of para-substituted phenols with an allylic carbonate unit to give spiro[4.5]cyclohexa-dienones in excellent yield. Reaction of propargyl carbonates with a palladium catalyst provides an equilibrium mixture of h-allenylpalladium(II) complexes and h-propargyl-palladium(II) complexes. Various catalytic transformations have been developed based on the electrophilic reactivity of these palladium complexes. We envisioned that these complexes would be adaptable to palladium-catalyzed intramolecular nucleophilic dearomatization of phenols, thus providing novel access to functionalized spirocyclohexadienones (Scheme 1). Moreover, the use of indole variants in the same catalytic process would result in the formation of aza-spirocycles. Herein, we report a novel synthetic method for spirocyclic molecules based on palladium-catalyzed intramolecular ipsoFriedel–Crafts alkylation of phenols and indoles. Mechanistic studies revealed that the reaction proceeds through an unprecedented rearomatization-assisted oxidative addition. Our studies began with the model substrate 1 a (Table 1). We first examined the reaction using 5 mol% [Pd(dba)2] and 12 mol% PPh3 in CH2Cl2, which are the

137 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023652
20221,161
2021561
2020516
2019630
2018631