Jiajia Cheng

• Fuzhou University

Heterogeneous photocatalysis offers potential solutions for energy conversion, yet its effectiveness is compromised by the intermittent nature of solar energy. This research explores the “dark” photocatalysis, with a specific emphasis on the electron storing process in cyanamide‐functionalized carbon nitride. In this study, cyanamide‐functionalized...

This study describes the synthesis and potential applications of pentaaryl-substituted pyrroles.

A photocatalytic process was developed for intermolecular reductive coupling of aliphatic ketones with alkynes/alkenes to furnish tertiary alcohols. Mechanistic studies support that boron carbonitrides (BCN) promote the single electron reduction of unactivated aliphatic ketones to generate ketyl radicals with visible light irradiation, which then r...

The ionic structure of poly(heptazine imides) has astrong implication in photocatalytic hydrogen generation. Fromnumerous reports, it is evident that these materials are also superiorto covalent carbon nitrides in various organic transformations. However, the reason has been remaining vague. Herein, we reportthe design of a molten-salt carbon nitri...

A novel and efficient approach for the synthesis of α, β‐unsaturated sulfones through heterogeneous photocatalyzed C−S coupling reactions have been developed. The use of molten‐salt method derived carbon nitride (MCN), a transition metal‐free polymeric photocatalyst, combined with enhanced crystallinity and potassium iodide as an additive, effectiv...

Carbon nitride (CN) polymers exhibit tunable and fascinating physicochemical properties and are thus an essential class of photocatalytic materials with potential applications. Although significant progress has been made in the fabrication of CN, the preparation of metal‐free crystalline CN via a straightforward method remains a considerable challe...

Light‐driven fixation of CO2 in organics has emerged as an appealing alternative for the synthesis of value‐added fine chemicals. Challenges remain in the transformation of CO2 as well as product selectivity due to its thermodynamic stability and kinetic inertness. Here we develop a boron carbonitride (BCN) with the abundant terminal B/N defects ar...

Light‐driven fixation of CO 2 in organics has emerged as an appealing alternative for the synthesis of value‐added fine chemicals. Challenges remain in the transformation of CO 2 as well as product selectivity due to its thermodynamic stability and kinetic inertness. Here we develop a boron carbonitride (BCN) with the abundant terminal B/N defects...

A visible-light-induced carboxylation of styrenes with CO2 has been developed by a halogen-atom-transfer pathway using alkyl iodides as promoters. Challenging alkyl iodides and CO2 could be assembled into electron-deficient styrenes...

The use of metal-free carbon nitride and light to drive catalytic transformations constitutes a sustainable strategy for organic synthesis. At the moment, enhancing the intrinsic activity of CN catalysts by tuning the interfacial coupling between catalyst and substrate remains challenging. Herein, we demonstrate that urea-derived carbon nitride cat...

Photocatalytic conversion of carbon dioxide (CO2) to valuable products is one of the promising approaches to mitigate climate change and provide chemical fuels. The structural design of photocatalysts has been therefore directed to enhancing the CO2 conversion efficiency and selectivity. Herein, we report that the metalated porous polycarbazoles, m...

The redox‐neutral palladium‐catalyzed dicarbofunctionalization of unactivated alkenes with a variety of functionalized difluoromethyl and perfluoroalkyl halide is presented here. This transformation proceeds smoothly at low temperatures and enables the assembly of diversified fluoroalkylated pyrrolo[1,2‐a]indole derivatives with one all‐carbon quat...

A facile and efficient quinoline-fused 4H-benzo[b][1,4]oxazine has been successfully fabricated through an oxidative O-arylation, Pd-catalyzed double N-arylation of 4-hydroxyquinoline derivatives and trivalent aryl iodides. Diversified fused heterocycles could be easily constructed in overall high isolated yields with great substrate scope. The aff...

Oxidation, especially selective oxidation by a heterogeneous catalyst with molecular oxygen, is a core technology for the conversion of petrochemical feedstock to commodity chemicals and pharmaceuticals. Existing catalytic approaches for efficient aerobic oxidation normally relies on the engagement of organometallic centers or transition-metal nano...

Near-infrared (NIR) light-responsive materials had attracted much attention by virtue of their ability to employ abundant light sources to adapt their properties remotely and spatially in which development of novel NIR light-responsive fillers was the key factor. In this work, cellulose nanocrystals (CNCs) were coated with polydopamine (PDA) to end...

Photocatalytic aerobic oxidation of alcohols for the direct synthesis of esters has received significant attention in recent years, but the relatively low efficiency and selectivity under visible light irradiation is the main challenge for their practical applications. Here, surface acidic sites were imparted onto metal-free heterogeneous photocata...

A Cu-catalyzed aerobic oxidative cyclization of β,γ-unsaturated hydrazones for the preparation of pyrazole derivatives has been developed. The hydrazonyl radical promoted the cyclization, along with a concomitant C═C bond cleavage of β,γ-unsaturated hydrazones. This process has been verified via several control experiments, including a radical-trap...

An efficient method for the copper‐catalyzed selective C−H difluoroalkylation of coumarins and with low cost and readily available ethyl bromodifluoroacetate and N‐phenyl bromodifluoroacetamide has been reported. This reaction exhibits good functional group tolerance with respect to coumarins and difluoroalkylation reagents, and several redox‐sensi...

Photocatalytic reactive oxygen species (ROS)-induced reactions provide an appealing method to solve the environmental and energy issues, whereas the current oxidation reaction generally suffered from low efficiency and poor selectivity due to uncontrollable O2 activation process. In view of the existence of competitive electron and energy transfer...

A green and scalable oxidation of 2-ethyl-3-methylpyrazine (EMP) by tert-butylhydroperoxide was investigated with a catalytic system of cobalt(II) and N-containing ligand. The effects of catalyst, ligand, solvent and temperature were compared, and the catalysis system of cobalt(II) acetylacetonate and 2, 2-bipyridine gave the highest selectivity. M...

An efficient method for visible-light-induced perfluoroalkylaion of quinolin-4-ol has been reported. In the presence of t-BuONa and perfluoroalkyl iodide, quinolin-4-ol underwent CH perfluoroalkylation under the irradiation of green light. Mechanistic studies demonstrated that visible-light promoted intermolecular charge transfer within the transie...

Crystalline carbon nitride (CCN)‐based semiconductors have recently attracted widespread attention in solar energy conversion. However, further modifying the photocatalytic ability of CCN always results in a trade‐off between high crystallinity and good photocatalytic performance. Herein, a facile defect engineering strategy was demonstrated to mod...

A divergent synthetic strategy to 1,6-dihydropyridazines and pyridazines through Cu(II)-catalyzed controllable aerobic 6-endo-trig cyclization was developed. The selectivity can be rationally tuned via the judicious choice of reaction solvent. It was found that the 1,6-dihydropyridazines were obtained in moderate to high yields with CH3CN as the re...

An efficient carbene organocatalyzed route to enantioenriched chromenones, bearing one tri- or difluoromethylated stereogenic center in the β position of the carbonyl group, from o-allyloxybenzaldehydes is described. The one-pot transition-metal-free transformation exhibits a broad substrate scope and excellent enantioselectivity.

A one‐pot transition‐metal free selective iodoarylation of pyrazoles with aryliodine diacetates is developed. The reaction proceeds via the in‐situ generation of NH‐pyrazole‐iodonium salts followed by sequential phen/K2CO3‐mediated intermolecular arylation. When iodonium ylide was directly used as substrate, the difunctionalization products could b...

A simple halogen‐bond‐promoted α‐C−H amination of ether/thioether with a variety of N−H compounds has been accomplished. In the presence of low‐cost and readily available perfluorobutyl iodide, a diverse range of hemiaminal ether derivatives, including the valuable hydrazone hemiaminal ethers, were quickly assembled under thermal or visible‐light i...

An efficient and user‐friendly synthesis of 7H‐chromeno[3,2‐c]quinolines has been developed via a one‐pot oxidative O‐arylation, Pd‐catalyzed C(sp ³ )‐H arylation of readily available arylols and trivalent aryliodine reagents. A variety of valuable and complex fused heterocycles were quickly assembled in high isolated yields with broad substrate sc...

A highly efficient catalytic system, CuSO4·5H2O/1-(4-methoxyphenyl)-3-phenylthiourea, for the copper(I)-catalyzed azide–alkyne cycloaddition reaction (CuAAC) was discovered. In the above catalytic system, substituted thiourea acts both as a reductant and a ligand. CuSO4·5H2O/1-(4-methoxyphenyl)-3-phenylthiourea is both an economical and efficient c...

An efficient and highly practical palladium-catalyzed arylperfluoroalkylation of unactivated olefins is presented here. A variety of perfluoroalkylated heterocyclic derivatives can be obtained in high regioselectivity. The reaction proceeds mildly without the electronic activation of the aryl group and features high generality, low-cost fluoroalkyl...

We report here an indium(III) triflate (In(OTf) 3 )‐catalyzed Prins‐type cyclization of disubstituted β‐allenols in the presence of aldehydes in dichloromethane (CH 2 Cl 2 ) affording different 3,6‐dihydro‐2 H ‐pyran at room temperature or 45 °C. The high efficiency of the reaction and easily available nature of the starting materials/catalyst make...

A facile environmentally-benign approach has been developed for the preparation of dynamic, multi-responsive and self-healing hydrogels from inexpensive bamboo pulp, poly(vinyl alcohol) (PVA) and borax. The microfibrillated cellulose (MFC) reinforced PVA-borax hydrogels were produced through a one-pot route in conjunction with ball milling and phys...

Convenient conditions using TmsCl as dehydrating agent and FeCl3 as the catalyst are developed for the tandem aza-Prins/Friedel—Crafts cyclization of allenes of type (I) and aldehydes.

A catalytic phenylation reaction of α,β-unsaturated acylazoliums with in-situ-generated phenolates was developed. A combination of N-heterocyclic carbene and potassium ion cooperatively catalyzed the generation of α,β-unsaturated acylazoliums and phenolates from α,β-unsaturated phenolic esters for the efficient [3+3] annulation, which involves a de...

An efficient approach for the synthesis of 1,2,3,4,5,6‐hexahydrobenzo[ f ]isoquinolines via a tandem aza‐Prins/Friedel–Crafts cyclization from 2‐arylethyl‐2,3‐butadienyl tosylamides and aldehydes has been developed. This iron(III) chloride‐catalyzed cascade cyclization at the room temperature with different types of aldehydes, such as aromatic and...

This efficient one-pot reaction leads to a wide range of heterocycles via sequential oxidation, iodination, isomerization, and cyclization steps without purification of any reaction intermediates.

A one‐pot, two‐step cyclization reaction of iodoarenes with diversified arylols, including 4‐hydroxyquinoline, quinolinone, 4‐hydroxypyridine and phenol, has been developed. By using this palladium‐catalyzed formal tandem O‐arylation, dehydrogenative cross‐coupling reaction, a variety of biologically significant fused benzo[4,5]furo heterocycles an...

The reaction mechanism of the γ-carbon addition of enal to imine under oxidative N-heterocyclic carbene catalysis is studied experimentally. The oxidation, γ-carbon deprotonation, and nucleophilic addition of γ-carbon to imine were found to be facile steps. The results of our study also provide highly enantioselective access to tricyclic sulfonyl a...

Pd-Catalyzed C-H functionalization of acyldiazomethanes with aryl iodides has been developed. This reaction is featured by the retention of the diazo functionality in the transformation, thus constituting a novel method for the introduction of diazo functionality to organic molecules. Consistent with the experimental results, the DFT calculation in...

Provided is a process for producing aldehydes or ketones by oxidizing alcohols with oxygen, which comprises oxidizing alcohols to aldehydes or ketones in an organic solvent at room temperature with oxygen or air as an oxidant, wherein ferric nitrate (Fe(NO3)3.9H2O), 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) and an inorganic chloride are used as...

Transition metal and organic catalysts have established their own domains of excellence. It has been expected that merging the two unique domains should provide complimentary or unprecedented opportunities in converting simple raw materials to functional products. N-heterocyclic carbenes alone are excellent organocatalysts. When used with transitio...

The direct sp3 C-H bond functionalization of 2-alkyl azaarenes to isatylidene malononitriles has been achieved using Bi(OTf)3 as the catalyst, resulting in a series of oxindoles containing an all-carbon quaternary center in moderate to good yields. This protocol provided an efficient and convenient method for the construction of potentially useful...

An effective wake-up call: Stable α,β-unsaturated esters were activated by the addition of a chiral N-heterocyclic carbene (NHC) organocatalyst, and the resulting reactive Michael acceptor intermediates reacted with enamide nucleophiles to furnish optically pure products (see scheme; Ts=p-toluenesulfonyl). These products can be converted readily in...

The FeCl3-mediated aza-Prins-cyclization reaction of α-sulfonamido-allenes (I) and (VI) with aldehydes affords selectively tetrahydropyridine (III) or dihydropyrrole derivatives (VIII), respectively.

A FeCl3-catalyzed Prins cyclization reaction of β-sulfonamidoallenes or β-allenols with aldehydes has been developed for the synthesis of 3-chloromethyl-1,2,5,6-tetrahydro-1H-pyridine or 3-chloromethyl-5,6-dihydro-2H-pyran. The reaction is highly selective due to the stability of the allyl cation intermediate.

FeCl(3)-catalyzed aza-Prins-cyclization reaction of α-sulfonamido-allenes with aldehydes afforded 1,2,3,6-tetrahydropyridine or 2,5-dihydro-1H-pyrrole derivatives efficiently and highly selectively. The different regioselectivity is probably caused by the stabilizing effect of the phenyl group on the positively charged allylic intermediate.

A three-component Pd(0)-catalyzed reaction of 1,5-bisallenes with organic halides in the presence of primary amines was observed to afford stereodefined not readily available ten-membered cyclic compounds highly chemo- and regioselectively. A mechanism involving two π-allylic palladium intermediates was proposed to account for the observed regio- a...

The reaction tolerates a wide range of aromatic and aliphatic amines and aromatic and alkenic iodides to afford the target pyrrole derivatives.

Oxidation of alcohols is a fundamental transformation related to our daily life. Traditional approaches with at least one stoichiometric amount of oxidants are expensive and cause serious environmental burdens. There are many reports on the aerobic oxidation of simple alcohols such as alkyl or phenyl carbinols and allylic alcohols, which used oxyge...

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A highly efficient, tetrakis(acetonitrile)copper(I) hexafluorophosphate [Cu(MeCN)4PF6]-catalyzed tandem Cu(I)-carbene NH insertion/Cu(I)-catalyzed hydroamination of alkynes, which leads to sequential formation of two CN bonds to yield isoindole derivatives, has been developed.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.