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A series of supported highly dispersed CuNi alloy nanocatalysts were fabricated by a coprecipitation method for the N-alkylation of aniline with 2,5-dihydroxymethylfuran under base-free conditions....

Porous organic frameworks (POFs) catalysts with a combination of the well-developed porosity and highly dispersed of active sites hold promise for boosting catalyst activity and selectivity. Among their many synthetic methods, one-step knitting strategies have gained superiority and potential for development. Here, two copper porphyrin based microporous polymers (SC-Cu and FC-Cu) were directly synthesized through Scholl coupling reaction and Friedel-Crafts alkylation reaction respectively, which possess high surface area and efficient catalytic performance for styrene oxidation. Moreover, the hierarchical pores of SC-Cu gave it a unique catalytic performance with various olefins with excellent conversion rate. The insight achieved by this systematic analysis will contribute to the rational design of other POFs catalysts and widening extent of applications.

The transition-metal-free synthesis of unsymmetrical and highly functionalized triarylmethanes through arylation of the situ generated o-QMs from diarylmethyl p-tolyl sulfones with aryl zinc reagents is described. Alkyl zinc reagents are also well tolerated in this reaction. Additionally, the straightforward synthesis of the analogue of the antituberculosis agent A and the key precursor of the anti-breast-cancer agent B are achieved by this strategy.

A tert-butyl peroxybenzoate (TBPB) mediated direct functionalization of N-propargyl aromatic amine derivatives with ethers has been developed. This procedure provides a new strategy toward the synthesis of 3-alkylated quinolines in one step via a domino radical addition/cyclization reaction under metal-free conditions.

We reported the first example of the construction of C–C bonds using unprotected amino acids as stable alkyl/acyl radical precursors under metal-free conditions. This novel, environmentally friendly, and one-pot procedure was successfully applied to the radical alkylation or acylation/cyclization of isocyanides, which selectively affords 6-alkyl or acyl phenanthridines, depending on the substituent pattern of amino acid side chain groups.

A visible-light-induced oxidative difunctionalization of activated alkenes with simple ethers via selective C(sp3)–H bond cleavage and dual C–C bond formation was developed. The reaction provides mild, efficient and atom economical access to alkylated oxindoles at room temperature under metal-free conditions.

An effective protocol of photoredox catalyzed C2-alkylation of benzothiazoles with aliphatic carboxylic acids was disclosed. In the presence of an acridinium salt as a photocatalyst and air as an oxidant, a wide range of secondary or tertiary aliphatic carboxylic acids were employed as alkylation reagents, providing the desired products in good to excellent yields under mild reaction conditions with a broad substrate scope.

Pure organic, heterogeneous, metal-free, and visible light-active photocatalysts offer a more sustainable and environmentally friendly alternative to traditional metal-based catalysts. Here we report a series of microporous organic polymers containing photoactive conjugated organic semiconductor units as heterogeneous photocatalysts for a visible-light-promoted, highly selective bromination reaction of electron-rich aromatic compounds using HBr as a bromine source and molecular oxygen as a clean oxidant. Via a simple Friedel–Crafts alkylation reaction, the microporous organic polymers were obtained by cross-linking of organic semiconductor compounds with defined valence and conduction band positions. The utilization of the simply prepared porous polymer-based photocatalytic systems opens new opportunities toward a sustainable and efficient material design for catalysis.

A novel Rh(III)-catalyzed direct alkylation of azobenzenes with allyl acetates through C-H activation and functionalization is demonstrated in which the allyl acetates serve as unique alkylation agents. The rhodium-catalyzed alkylation provides a highly efficient and atom-economic approach to a series of azo compounds.

Efficient strategies for the solid phase synthesis of constrained macrocyclic peptides are valuable tools for the generation of potentially biologically active compound libraries. In particular, the use of covalent linkers as hydrogen bond surrogates for the initiation and stabilization of α-helical secondary structures, resulting in the formation of a 13-membered macrocycle, is a validated approach. For these purposes, a straightforward synthetic pathway was developed, employing natural amino acids bearing usual protecting groups and mediated through two Fukuyama–Mitsunobu alkylation reactions on unprotected 1,3-propanediol on solid phase. The linear precursors were obtained in good purity and moderate yields, and the final cyclization step was carried out in solution.

Fundamental research on ionic liquids has promoted their wide applications including catalysis, organic synthesis and materials, which provides new method for developing green catalysis processes. This article reviews some representative ionic liquid-based catalytic reactions, such as CO2 cycloaddition, alkylation, hydroformylation, transesterification, oxidation, CO2 hydrogenation, cross-polymerization and depolymerization, with the aiming of highlighting the roles of ionic liquids on reaction efficiency, the reduction of emissions and separation. Furthermore, the prospective to the development in this field is discussed.

A novel RhIII-catalyzed direct alkylation of azobenzenes with allyl acetates through C–H activation and functionalization is demonstrated in which the allyl acetates serve as unique alkylation agents. The rhodium-catalyzed alkylation provides a highly efficient and atom-economic approach to a series of azo compounds.

An enantioselective Friedel-Crafts alkylation/cyclization cascade reaction of 1-naphthols and alpha,beta-unsaturated aldehydes promoted by diphenylprolinol ether has been developed. The method affords one-pot access to chiral and synthetically useful chromanes and dihydrobenzopyranes in high yields and enantioselectivities from readily available compounds. In addition, the addition/cyclization products could be afterward transformed to various natural products and biologically active derivatives. On the basis of the experimental results and the observed absolute configurations of the products, a plausible mechanism has been proposed to explain the origin of the activation and the asymmetric induction.

The Lewis base-Lewis base bifunctional catalytic system has been developed and successfully applied to the asymmetric Friedel-Crafts alkylation of indoles with α,β-unsaturated aldehydes. The reactions are promoted by chiral diphenylprolinol trimethylsilyl ether in the presence of triethylamine. By this protocol, optically active 3-substituted indoles can be obtained in an organocatalytic process that is free of Lewis or protic acid in high yields with up to 98% ee. Besides, this reaction could be carried out on a gram scale without any loss in the enantioselectivity.

An efficient and convenient method for the direct hydroalkylation of styrene and norborene with 1,3-diketones has been developed by using 12-phosphotungstic acid as an eco-friendly, and air- and moisture-tolerable catalyst. Reactions proceeded without any solvent, providing a clean access to alkylated 1,3-diketones.

Activation parameters are reported for additions of phenylchlorocarbene (PhCCl), pentafluorophenylchlorocarbene (F5-PhCCl), and 3,5-dinitrophenyl-chlorocarbene (3,5-DN-PhCCl) to tetramethylethylene (TME), cyclohexene, and 1-hexene. The order of activation enthalpies is F5-PhCCl > PhCCl > 3,5-DN-PhCCl. Activation enthalpies also increase as the degree of alkene alkylation decreases. In general, the entropies of activation increase in tandem with the enthalpies of activation.

Two chiroptical spectroscopic techniques, namely, electronic and vibrational circular dichroism (ECD and VCD), as well as NMR spectroscopy have been utilized to determine the absolute configurations and geometries of two Frater-Seebach alkylation reaction products with long hydrocarbon chains. The experimental studies have been complemented with density functional theory calculations. Strong characteristic bisignate VCD signatures in the carbonyl stretching region have been observed for both compounds in film state. Truncated models, i.e., without the long CH2 chains, have been utilized to examine different hydrogen-bonding topologies between two monomeric moieties and to simulate the corresponding IR and VCD spectra of the dimers. In addition, the exciton coupling model has also been applied to the -C═O groups of the two monomeric moieties, which can be coupled through intermolecular hydrogen-bonding. On the basis of these simplified approaches, the absolute configurations of the compounds have been unambiguously assigned using VCD and ECD spectroscopy. Spectral simulations in the IR and UV-vis regions have also been carried out with the full dimers to validate the fitness of the truncated model. The study shows that the combination of the film VCD and ECD techniques is a relatively straightforward method to determine the absolution configurations of such synthetic compounds.

An alkylated cage silsesquioxane (1), targeting for a new class of bottom-up-type fabricating materials, was successfully synthesized, and its self-assembled structure is described and discussed herein. Through this, it was found that the intermolecular interaction of long alkyl chains of 1 could be manipulated by thermal annealing to form a long-range straight ordered hierarchical lamellar structure with a periodicity of around 5 nm. Subsequent transmission electron microscopy (TEM) clearly identified polyhedral oligomeric silsesquioxane (POSS) molecules of 1 arranged in a highly ordered fashion, with a "head-to-head" type bilayered structure. The observation of a sublayer structure measuring approximately 0.4 nm in width was attributed to the highly regular packing of isobutyl groups in POSS molecules identified by TEM analysis. Moreover, the formation of a long-range straight structure with sharp interfacial boundaries, which is difficult to achieve with traditional diblock copolymers, is considered to be of significant importance to developing new practical applications of self-assembled nanostructures.

The first synthetic attempt commencing from an eight-membered ring to approach the [5.3.1] bicyclic core of vinigrol has demonstrated the feasibility of using the conformational bias of the cyclooctane-ring system to realize highly diastereoselective reactions. The synthetic potential of the newly disclosed access to in/out isomerism may stimulate broader interests.

Activation parameters are reported for ClCCF3 additions to three alkenes (tetramethylethylene, cyclohexene, and 1-hexene). The results are compared to those for CCl2, CClF, and CF2. Activation enthalpies decrease as the carbene stability decreases and its electrophilicity increases, and also as alkene reactivity (degree of alkylation) increases. Activation entropies decrease in parallel with activation enthalpies, suggesting the operation of enthalpy–entropy compensation in these carbene additions.

A broad spectrum of transformations is investigated in the presence of the different catalytic systems.

Direct application of benzyl alcohols (or their magnesium salts) as electrophiles in various reactions with Grignard reagents has been developed via transition metal-catalyzed sp(3) C-O bond activation. Ni complex was found to be an efficient catalyst for the first direct cross coupling of benzyl alcohols with aryl/alkyl Grignard reagents, while Fe, Co, or Ni catalysts could promote the unprecedented conversion of benzyl alcohols to benzyl Grignard reagents in the presence of (n)hexylMgCl. These methods offer straightforward pathways to transform benzyl alcohols into a variety of functionalities.

A variety of secondary and tertiary alcohols, linear and cyclic ethers react with benzothiazole, benzoxazole and benzimidazole.

A metal-free novel, simple, and highly efficient method for the direct C2-alkylation of azoles with alcohols and ethers has been developed on the basis of an oxidative C-H activation process. The dehydrogenative C-C cross-coupling reactions of α-position sp(3) C-H in alcohols and ethers with the 2-position sp(2) C-H in azoles proceeded smoothly in the presence of tert-butyl hydroperoxide (TBHP) under neat reaction conditions, which generated the corresponding products in good yields.

The Lewis base-Lewis base bifunctional catalytic system has been developed and successfully applied to the asymmetric Friedel-Crafts alkylation of indoles with α,β-unsaturated aldehydes. The reactions are promoted by chiral diphenylprolinol trimethylsilyl ether in the presence of triethylamine. By this protocol, optically active 3-substituted indoles can be obtained in an organocatalytic process that is free of Lewis or protic acid in high yields with up to 98% ee. Besides, this reaction could be carried out on a gram scale without any loss in the enantioselectivity.

An enantioselective Friedel-Crafts alkylation of 4,7-dihydroindoles and alpha,beta-unsaturated aldehydes has been developed. The process is promoted by diphenylprolinol ether to afford 2-substituted 4,7-dihydroindoles in high yields and enantioselectivities. After a subsequent oxidation of the products, the optically active 2-substituted indoles could be obtained smoothly in high yields without any loss of enantioselectivity.

An efficient and convenient method for the direct hydroalkylation of styrene and norborene with 1,3-diketones has been developed by using 12-phosphotungstic acid as an eco-friendly, and air- and moisture-tolerable catalyst. Reactions proceeded without any solvent, providing a clean access to alkylated 1,3-diketones.

A series of 2,3;6,7-tetra(methoxy)-9,10-di(aryl)anthracene derivatives have been readily synthesized by acid-catalyzed Friedel-Crafts alkylation of aromatic aldehydes with veratrole. These compounds have good thermal and morphological stability. Their highest occupied molecular orbital (HOMO: −5.23– −5.28 eV)/lowest unoccupied molecular orbital (LUMO: −2.11– −2.28 eV) energy levels are energetically favorable for use as hole-transporting/electron-blocking layers in organic light-emitting devices (OLEDs). Device performance of these non-amine based hole-transporting materials were comparable to or better than that of the traditional arylamine derivative NPB. The optimized green doped three-layer device based on 2,3;6,7-tetra(methoxy)-9,10-di(1-naphthyl)anthracene (TMOADN) exhibited a current efficiency of 25.6 cd A−1 (13.4 lm W−1) at 20 mA cm−2 with an external quantum efficiency of 7.05%.