Semiconductor photocatalysis to engineering deuterated N-alkyl pharmaceuticals enabled by synergistic activation of water and alkanols

Selectively Deoxygenative Deuteration of Aldehydes by Superwetting Porous Carbon-Supported Palladium Catalysts

We present a method of deoxygenative deuteration of aldehydes (DDA) over heterogeneously superwetting porous carbon-supported palladium catalyst (Pd/SPC), which is efficient for the synthesis of deuterated aromatic compounds with -CD3 group. Exemplified by the DDA reaction of 2-naphthaldehyde (2-NAL) to 2-methylnaphthalene (2-MNE), the total deuterium incorporation radio in the resultant aromatic hydrocarbons was higher than 95% and the selectivity toward 2-MNE-d3 reached 87%. The impressed catalytic activity was found relevant to the combined effect of surface wettability and the electron-rich properties of Pd species of this kind of heterogeneous Pd/SPC catalyst. Mechanistic studies suggest a successive deuteration pathway, that is, hydrogen isotope exchange (HIE), deuterium addition, and ultimate deoxygenative deuteration over Pd/SPC in the cost-effective D2O/H2 reaction conditions. The in situ-formed D2 from the first step HIE between H2 and D2O can be readily captured by the electron-rich Pd centers, which then boost the subsequent deuterogenolysis of C─O bonds through deuterated alcohol intermediates toward the formation of 2-MNE-d3. This work provides a design principle of heterogeneous catalysts for targeted deuterium labeling from aldehyde substrates and may inspire the development of alternative deuterium labeling techniques beyond dominated homogeneous catalysis.

Electrochemical debrominative hydrogenation/deuteration of 2-bromo-N-arylacetamides

Herein, we report a facile and efficient electro-reductive debrominative hydrogenation/deuteration of 2-bromo-N-aryl acetamides using H2O/D2O as an economical source of hydrogen/deuterium at room temperature. The reactions proceeded efficiently via C-Br bond activation, enabling facile synthesis of a range of N-substituted amides in moderate to high yields with broad functional group compatibility.

Construction of axially chiral molecules enabled by photoinduced enantioselective reactions

Axially chiral molecular scaffolds are widely found in pharmaceutical molecules, functionalized materials, and chiral ligands. The synthesis of these compounds has garnered considerable interest from both academia and industry. The construction of such molecules, enabled by transition metal catalysis and organocatalysis under thermodynamic conditions, has been extensively studied and well-reviewed. In recent years, photoinduced enantioselective reactions have emerged as powerful methods for the catalytic construction of axial chirality. In this review, we provide an overview of various synthetic strategies for the photoinduced construction of axial chirality, with a specific focus on reaction design and catalytic mechanisms. Additionally, we discuss the limitations of current methods and highlight future directions in this field.

Poly(2,2'-Bibenzimidazole)-Supported Iridium Complex: A Recyclable Metal-Polymer Ligand Bifunctional Catalyst for the N-Methylation of Amines with Methanol

The design and development of new types of catalysts is one of the most important topics for modern chemistry. Herein, a polymer-supported iridium complex Cp*Ir@Poly(2,2'-BiBzIm) was designed and synthesized by the coordinative immobilization of [Cp*IrCl2]2 on 2,2'-bibenzimidazoles. In the presence of the catalyst (0.5 mol % Ir) and Cs2CO3 (0.3 equiv), a variety of N-methylated amines were obtained in high yields with complete selectivity. More importantly, the catalyst could be recycled without an obvious loss of activity for six cycles. Apparently, the designed catalyst combines the advantages of both homogeneous and heterogeneous catalysis.

Modulation of Electronic Availability in g-C3N4 Using Nickel (II), Manganese (II), and Copper (II) to Enhance the Disinfection and Photocatalytic Properties

Carbon nitrides can form coordination compounds or metallic oxides in the presence of transition metals, depending on the reaction conditions. By adjusting the pH to basic levels for mild synthesis with metals, composites like g-C3N4-M(OH)x (where M represents metals) were obtained for nickel (II) and manganese (II), while copper (II) yielded coordination compounds such as Cu-g-C3N4. These materials underwent spectroscopic and electrochemical characterization, revealing their photocatalytic potential to generate superoxide anion radicals-a feature consistent across all metals. Notably, the copper coordination compound also produced significant hydroxyl radicals. Leveraging this catalytic advantage, with band gap energy in the visible region, all compounds were activated to disinfect E. coli bacteria, achieving total disinfection with Cu-g-C3N4. The textural properties influence the catalytic performance, with copper's stabilization as a coordination compound enabling more efficient activity compared to the other metals. Additionally, the determination of radicals generated under light in the presence of dicloxacillin supported the proposed mechanism and highlighted the potential for degrading organic molecules with this new material, alongside its disinfectant properties.

Direct Cyanoalkylation of Imines Driven by a Photoactive Electron Donor-Acceptor Complex

β-Amino nitriles are important molecular scaffolds. Cyanoalkylation of imines is the most straightforward method for the construction of these scaffolds. In this study, we report the novel cyanoalkylation of imines via radical coupling enabled by a photoactive electron donor-acceptor complex. This strategy is characterized by mild conditions, broad reaction scopes, and high atom economy. The scalability and practicality of this strategy are demonstrated by a 40 g continuous flow system from which a variety of important pharmaceutical-related molecules were obtained.

A Recyclable Inorganic Lanthanide Cluster Catalyst for Chemoselective Aerobic Oxidation of Thiols

Optimizing lanthanide catalyst performance with organic ligands often encounters significant challenges, including susceptibility to water or oxygen and complex synthesis pathways. To address these issues, our research focuses on developing inorganic lanthanide clusters with enhanced stability and functionality. In this study, we introduce the [Sm6O(OH)8(H2O)24]I8(H2O)8 cluster (Sm-OC) as a sustainable and efficient catalyst for the aerobic oxidation of thiols under heating conditions. The Sm-OC catalyst demonstrated remarkable stability, outstanding recyclability, and excellent chemoselectivity across a diverse range of functional groups in 38 different tests. Notably, it enables efficient unsymmetrical disulfide synthesis and prevents the formation of over-oxidized by-products, highlighting its superior performance. This Sm-OC catalyst provides a practical and robust tool for the precise construction of versatile disulfides, thus establishing a template for the broader use of lanthanide clusters in organic synthesis.

Heterogeneous Organocatalysts for Light-Driven Reactions in Continuous Flow

Within the realm of organic synthesis, photocatalysis has blossomed since the beginning of the last decade. A plethora of classical reactivities, such as selective oxidation of alcohol and amines, redox radical formation of reactive species in situ, and indirect activation of an organic substrate for cycloaddition by EnT, have been revised in a milder and more sustainable fashion via photocatalysis. However, even though the spark of creativity leads scientists to explore new reactions and reactivities, the urgency of replacing the toxic and critical metals that are involved as catalysts has encouraged chemists to find alternatives in the branch of science called organocatalysis. Unfortunately, replacing metal catalysts with organic analogues can be too expensive sometimes; however, this drawback can be solved by the reutilization of the catalyst if it is heterogeneous. The aim of this review is to present the recent works in the field of heterogeneous photocatalysis, applied to organic synthesis, enabled by continuous flow. In detail, among the heterogeneous catalysts, g-CN, polymeric photoactive materials, and supported molecular catalysts have been discussed within their specific sections, rather than focusing on the types of reactions.

Harnessing alcohols as sustainable reagents for late-stage functionalisation: synthesis of drugs and bio-inspired compounds

Alcohol is ubiquitous with unparalleled structural diversity and thus has wide applications as a native functional group in organic synthesis. It is highly prevalent among biomolecules and offers promising opportunities for the development of chemical libraries. Over the last decade, alcohol has been extensively used as an environmentally friendly chemical for numerous organic transformations. In this review, we collectively discuss the utilisation of alcohol from 2015 to 2023 in various organic transformations and their application toward intermediates of drugs, drug derivatives and natural product-like molecules. Notable features discussed are as follows: (i) sustainable approaches for C-X alkylation (X = C, N, or O) including O-phosphorylation of alcohols, (ii) newer strategies using methanol as a methylating reagent, (iii) allylation of alkenes and alkynes including allylic trifluoromethylations, (iv) alkenylation of N-heterocycles, ketones, sulfones, and ylides towards the synthesis of drug-like molecules, (v) cyclisation and annulation to pharmaceutically active molecules, and (vi) coupling of alcohols with aryl halides or triflates, aryl cyanide and olefins to access drug-like molecules. We summarise the synthesis of over 100 drugs via several approaches, where alcohol was used as one of the potential coupling partners. Additionally, a library of molecules consisting over 60 fatty acids or steroid motifs is documented for late-stage functionalisation including the challenges and opportunities for harnessing alcohols as renewable resources.

Photo-Induced C1 Substitution Using Methanol as a C1 Source

The development of sustainable and efficient C1 substitution methods is of central interest for organic synthesis and pharmaceuticals production, the methylation motifs bound to a carbon, nitrogen, or oxygen atom widely exist in natural products and top-selling drugs. In the past decades, a number of methods involving green and inexpensive methanol have already been disclosed to replace industrial hazardous and waste-generating C1 source. Among the various efforts, photochemical strategy is considered as a "renewable" alternative that shows great potential to selectively activate methanol to achieve a series of C1 substitutions at mild conditions, typically C/N-methylation, methoxylation, hydroxymethylation, and formylation. Herein the recent advances in selective transformation of methanol to various C1 functional groups via well-designed photochemical systems involving different types of catalysts or not is systematically reviewed. Both the mechanism and corresponding photocatalytic system were discussed and classified on specific methanol activation models. Finally, the major challenges and perspectives are proposed.

Transition-metal-free silylboronate-mediated cross-couplings of organic fluorides with amines

C-N bond cross-couplings are fundamental in the field of organic chemistry. Herein, silylboronate-mediated selective defluorinative cross-coupling of organic fluorides with secondary amines via a transition-metal-free strategy is disclosed. The cooperation of silylboronate and potassium tert-butoxide enables the room-temperature cross-coupling of C-F and N-H bonds, effectively avoiding the high barriers associated with thermally induced S_N2 or S_N1 amination. The significant advantage of this transformation is the selective activation of the C-F bond of the organic fluoride by silylboronate without affecting potentially cleavable C-O, C-Cl, heteroaryl C-H, or C-N bonds and CF₃ groups. Tertiary amines with aromatic, heteroaromatic, and/or aliphatic groups were efficiently synthesized in a single step using electronically and sterically varying organic fluorides and N-alkylanilines or secondary amines. The protocol is extended to the late-stage syntheses of drug candidates, including their deuterium-labeled analogs.

Metal-Free Electrochemically Reductive Deuteration of C═N Bonds with D2O toward Deuterated Amines

Environmentally friendly and highly efficient synthesis of α-deuterated amines is achieved via a concise electrochemical process using D₂O as deuterium source without any external reductants or catalysts. Various imines are compatible, affording the desired products in high yields and D-incorporation. Gram-scale synthesis and flow-cell electrochemistry technology are used to synthesize deuterated pharmaceutical amines and their intermediates. Mechanistic studies reveal a plausible process, including the formation of carbanion species followed by deuterium atom transfer.

Catalytic asymmetric deuterosilylation of exocyclic olefins with mannose-derived thiols and deuterium oxide

Metal-free, photoinduced asymmetric deuterosilylation of exocyclic olefins has been achieved using a mannose-derived thiol catalyst.

One-pot H/D exchange and low-coordinated iron electrocatalyzed deuteration of nitriles in D2O to α,β-deuterio aryl ethylamines

Developing a step-economical approach for efficient synthesis of α,β-deuterio aryl ethylamines (α,β-DAEAs) with high deuterium ratios using an easy-to-handle deuterated source under ambient conditions is highly desirable. Here we report a room-temperature one-pot two-step transformation of aryl acetonitriles to α,β-DAEAs with up to 92% isolated yield and 99% α,β-deuterium ratios using D2O as a deuterium source. The process involves a fast α-C - H/C - D exchange and tandem electroreductive deuteration of C ≡ N over an in situ formed low-coordinated Fe nanoparticle cathode. The moderate adsorptions of nitriles/imine intermediates and the promoted formation of active hydrogen (H*) on unsaturated Fe sites facilitate the electroreduction process. In situ Raman confirms co-adsorption of aryl rings and the C ≡ N group on the Fe surface. A proposed H*-addition pathway is confirmed by the detected hydrogen and carbon radicals. Wide substrate scope, parallel synthesis of multiple α,β-DAEAs, and successful preparation of α,β-deuterated Melatonin and Komavine highlight the potential.

Electrocatalytic hydrogenation of quinolines with water over a fluorine-modified cobalt catalyst

Room temperature and selective hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines using a safe and clean hydrogen donor catalyzed by cost-effective materials is significant yet challenging because of the difficult activation of quinolines and H₂. Here, a fluorine-modified cobalt catalyst is synthesized via electroreduction of a Co(OH)F precursor that exhibits high activity for electrocatalytic hydrogenation of quinolines by using H₂O as the hydrogen source to produce 1,2,3,4-tetrahydroquinolines with up to 99% selectivity and 94% isolated yield under ambient conditions. Fluorine surface-sites are shown to enhance the adsorption of quinolines and promote water activation to produce active atomic hydrogen (H*) by forming F⁻-K⁺(H₂O)₇ networks. A 1,4/2,3-addition pathway involving H* is proposed through combining experimental and theoretical results. Wide substrate scopes, scalable synthesis of bioactive precursors, facile preparation of deuterated analogues, and the paired synthesis of 1,2,3,4-tetrahydroquinoline and industrially important adiponitrile at a low voltage highlight the promising applications of this methodology.

Selective hydrogenation of quinolines with easy-to-handle hydrogen donors and cost-effective catalysts is desirable. Here electrocatalytic quinoline hydrogenation to 1,2,3,4-tetrahydroquinolines is reported with water over a fluorine-modified cobalt.

Photocatalytic Applications of g-C3N4 Based on Bibliometric Analysis

To further understand the application of g-C3N4 in the field of photocatalysis, this study focuses on the visualization and analysis of articles in this field using VOSviewer and Citespace. These articles were analyzed in terms of number of articles, journals, authors, countries and keywords, respectively. The results show that there is little collaboration among the core authors in this field and insufficient cross-directional communication; the current applications of g-C3N4 are concentrated on hydrogen evolution, CO2 reduction and water treatment. The developing trend is in the direction of constructing Z-scheme structures, regulating the separation of photogenerated carriers and reducing the recombination rate, to which more and more attention is being paid. In the future, cross-directional communication among scholars can be strengthened to promote faster development of the field of photocatalytic applications of g-C3N4.

Radical deuteration

Deuterated chemicals are becoming irreplaceable in pharmaceutical engineering, material science and synthetic chemistry. Many excellent reviews have discussed acid/base-dependent or metal-catalyzed deuteration reactions, but radical deuterations have been discussed less. With the development of radical chemistry, there has been a rapid growth in radical deuterium-labelling technology. Diverse mild, cheap and efficient strategies for deuterium atom installation have been reported, and this review summarizes the recent achievements of radical deuteration classified by the reaction types.

Photocatalytic dehydrogenative C-C coupling of acetonitrile to succinonitrile

The coupling of acetonitrile into succinonitrile, an important terminal dinitrile for value-added nylon production, via a dehydrogenative route is highly attractive, as it combines the valuable chemical synthesis with the production of green hydrogen energy. Here, we demonstrate that it is possible to achieve a highly selective light driven dehydrogenative coupling of acetonitrile molecules to synthesize succinonitrile using anatase TiO₂ based photocatalysts in aqueous medium under mild conditions. Under optimized conditions, the formation rate of succinonitrile reaches 6.55 mmol/(g_cat*h), with over 97.5% selectivity to target product. Mechanism studies reveal that water acts as cocatalyst in the reaction. The excited hole of anatase semiconductor oxidizes water forming hydroxyl radical, which subsequently assists the cleavage of sp³ C-H bond of acetonitrile to generate ·CH₂CN radical for further C-C coupling. The synergy between TiO₂ and Pt cocatalyst is important to enhance the succinonitrile selectivity and prevent undesirable over-oxidation and hydrolysis. This work offers an alternative route to prepare succinonitrile based on renewable energy under mild conditions and avoid the use of toxic reagents and stoichiometric oxidative radical initiators.

Photocatalytic CO2 Reduction Coupled with Alcohol Oxidation over Porous Carbon Nitride

The photocatalytic transformation of CO2 to valuable man-made feedstocks is a promising method for balancing the carbon cycle; however, it is often hampered by the consumption of extra hole scavengers. Here, a synergistic redox system using photogenerated electron-hole pairs was constructed by employing a porous carbon nitride with many cyanide groups as a metal-free photocatalyst. Selective CO2 reduction to CO using photogenerated electrons was achieved under mild conditions; simultaneously, various alcohols were effectively oxidized to value-added aldehydes using holes. The results showed that thermal calcination process using ammonium sulfate as porogen contributes to the construction of a porous structure. As-obtained cyanide groups can facilitate charge carrier separation and promote moderate CO2 adsorption. Electron-donating groups in alcohols could enhance the activity via a faster hydrogen-donating process. This concerted photocatalytic system that synergistically utilizes electron-hole pairs upon light excitation contributes to the construction of cost-effective and multifunctional photocatalytic systems for selective CO2 reduction and artificial photosynthesis.

Sodium alkoxide-mediated g-C3N4 immobilized on a composite nanofibrous membrane for preferable photocatalytic activity

g-C3N4 is a classic photocatalyst not only owing to the metal-free semiconducting electronic structure but also tunable multifunctional properties. However, strategies for chemical exfoliation of g-C3N4 based on organic bases have been rarely reported. A family of sodium alkoxide-mediated g-C3N4 has been prepared via a simple synthesis. The degradation rate of bulk g-C3N4 is 39.8% when irradiation lasts 140 minutes. However, the degradation rate of g-C3N4-MeONa, g-C3N4-EtONa, and g-C3N4- t BuONa is 55.1%, 68.6%, and 79.1%, respectively, under the same conditions. Furthermore, g-C3N4- t BuONa has been immobilized on flexible electrospun PAN nanofibers to prepare floating photocatalysts. SEM analysis shows that the paper-based photocatalyst PAN/g-C3N4- t BuONa becomes a nanofiber membrane (A4 size, 210 mm × 297 mm). The nanofiber is approximately 350 nm in diameter. Interestingly, once synthesized, the g-C3N4- t BuONa particles move into the spinning solution, where the nanofiber wraps around them to form a monodisperse structure that resembles beads, or knots of 1-2 μm, on a string. The degradation efficiency of 10 mg L-1 MB solution can reach 100% for 2 hours until the solution becomes colorless. In addition, the photocatalytic mechanism studies have been validated. Different from H2SO4 or HNO3, this work has proposed a facile strategy for designing preferable floating photocatalysts using sodium alkoxide.

Recent Developments for the Deuterium and Tritium Labeling of Organic Molecules

Organic compounds labeled with hydrogen isotopes play a crucial role in numerous areas, from materials science to medicinal chemistry. Indeed, while the replacement of hydrogen by deuterium gives rise to improved absorption, distribution, metabolism, and excretion (ADME) properties in drugs and enables the preparation of internal standards for analytical mass spectrometry, the use of tritium-labeled compounds is a key technique all along drug discovery and development in the pharmaceutical industry. For these reasons, the interest in new methodologies for the isotopic enrichment of organic molecules and the extent of their applications are equally rising. In this regard, this Review intends to comprehensively discuss the new developments in this area over the last years (2017-2021). Notably, besides the fundamental hydrogen isotope exchange (HIE) reactions and the use of isotopically labeled analogues of common organic reagents, a plethora of reductive and dehalogenative deuteration techniques and other transformations with isotope incorporation are emerging and are now part of the labeling toolkit.

Synthesis, solid state self-assembly driven by antiparallel π⋯π stacking and {⋯H-C-C-F}2 dimer synthons, and in vitro acetyl cholinesterase inhibition activity of phenoxy pendant isatins

A series of novel phenoxy pendant isatins PI1-12 have been synthesized in excellent yields by a simple nucleophilic substitution reaction involving isatins and 1-(2-bromoethoxy)-4-substituted benzenes, and characterized by their FT-IR, ¹H NMR, ¹³C NMR and GC-MS data, and in the case of PI4 by its single crystal X-ray analysis. The solid-state structure of PI4 showed an intriguing and unique 1D-supramolecular chain-based self-assembled structure, the driving force of which is mainly the strong antiparallel π⋯π stacking and {⋯H-C-C-F}₂ dimer synthons. This compound not only highlights the potential of the isatin moiety in forming strong antiparallel π⋯π stacking interactions but also provides a platform to have considerable insight into the nature, strength and directionality of much debated π-π and C-H⋯F-C interactions. The in vitro biological studies revealed that three phenoxy pendant isatins PI1, PI2 and PI4 are highly potent inhibitors of acetylcholinesterase enzyme with IC₅₀ values of 0.52 ± 0.073 μg ml^-1, 0.72 ± 0.012 μg ml^-1 and 0.68 ± 0.011 μg ml^-1, respectively, showing comparable activity to the standard drug, donepezil (IC₅₀ = 0.73 ± 0.015 μg ml^-1). A simple and efficient synthesis of phenoxy pendant isatins PI1-12 from inexpensive and commercially available starting materials, and their high potential of acetyl cholinesterase inhibition provide an attractive opportunity to find more effective medication for Alzheimer's disease (AD).

Platinum on Carbon-Catalysed Site-Selective H-D Exchange Reaction of Allylic Alcohols Using Alkyl Amines as a Hydrogen Source

We developed platinum on carbon-catalysed deuteration reaction of tert-allylic alcohols using deuterium oxide as a deuterium source. Amylamine was dehydrogenated by platinum on carbon to generate an appropriate amount of...

Current Electrochemical Approaches to Selective Deuteration

The selective deuteration of organic molecules through electrochemistry is proving to be an effective alternative to conventional 2H labelling strategies, which traditionally require high temperatures, high pressures of deuterium gas...

Copper-catalysed low-temperature water-gas shift reaction for selective deuteration of aryl halides

The introduction of deuterium atoms into organic compounds is of importance for basic chemistry, material sciences, and the development of drugs in the pharmaceutical industry, specifically for identification and quantification of metabolites. Hence, methodologies for the synthesis of selectively labelled compounds continue to be a major area of interest for many scientists. Herein, we present a practical and stable heterogeneous copper catalyst, which permits for dehalogenative deuteration via water–gas shift reaction at comparably low temperature. This novel approach allows deuteration of diverse (hetero)aryl halides with good functional group tolerance, and no reduction of the aromatic rings or other easily reducible formyl and cyano groups. Multi-gram experiments show the potential of this method in organic synthesis and medicinal chemistry.

A practical and stable heterogeneous copper catalyst has been developed for dehalogenative deuteration via water–gas shift reaction at low temperature, allowing deuteration of diverse (hetero)aryl halides with good functional group tolerance.

Tandem H/D Exchange-SET Reductive Deuteration Strategy for the Synthesis of α,β-Deuterated Amines Using D2O

α,β-Deuterated amines are crucial for the development of deuterated drugs. We intend to introduce the novel tandem H/D exchange-single electron transfer (SET) reductive deuteration strategy with high pot- and reagent-economy by the synthesis of α,β-deuterated amine using nitrile as the precursor. The H/D exchange of the -CH₂CN group was achieved by D₂O/Et₃N, which were also the required reagents in the tandem SmI₂-mediated SET reductive deuteration of the α-deuterated nitrile. The potential application of this method was further showcased by the synthesis of bevantolol-d₄.

Photoredox-Catalyzed Simultaneous Olefin Hydrogenation and Alcohol Oxidation over Crystalline Porous Polymeric Carbon Nitride

Booming of photocatalytic water splitting technology (PWST) opens a new avenue for the sustainable synthesis of high-value-added hydrogenated and oxidized fine chemicals, in which the design of efficient semiconductors for the in-situ and synergistic utilization of photogenerated redox centers are key roles. Herein, a porous polymeric carbon nitride (PPCN) with a crystalline backbone was constructed for visible light-induced photocatalytic hydrogen generation by photoexcited electrons, followed by in-situ utilization for olefin hydrogenation. Simultaneously, various alcohols were selectively transformed to valuable aldehydes or ketones by photoexcited holes. The porosity of PPCN provided it with a large surface area and a short transfer path for photogenerated carriers from the bulk to the surface, and the crystalline structure facilitated photogenerated charge transfer and separation, thus enhancing the overall photocatalytic performance. High reactivity and selectivity, good functionality tolerance, and broad reaction scope were achieved by this concerted photocatalysis system. The results contribute to the development of highly efficient semiconductor photocatalysts and synergistic redox reaction systems based on PWST for high-value-added fine chemical production.

Photocatalytic Water-Splitting Coupled with Alkanol Oxidation for Selective N-alkylation Reactions over Carbon Nitride

Photocatalytic water splitting technology (PWST) enables the direct use of water as appealing "liquid hydrogen source" for transfer hydrogenation reactions. Currently, the development of PWST-based transfer hydrogenations is still in an embryonic stage. Previous reports generally centered on the rational utilization of the in situ generated H-source (electrons) for hydrogenations, in which photogenerated holes were quenched by sacrificial reagents. Herein, the fully-utilization of the liquid H-source and holes during water splitting is presented for photo-reductive N-alkylation of nitro-aromatic compounds. In this integrate system, H-species in situ generated from water splitting were designed for nitroarenes reduction to produce amines, while alkanols were oxidized by holes for cascade alkylating of anilines as well as the generated secondary amines. More than 50 examples achieved with a broad range scope validate the universal applicability of this mild and sustainable coupling approach. The synthetic utility of this protocol was further demonstrated by the synthesis of existing pharmaceuticals via selective N-alkylation of amines. This strategy based on the sustainable water splitting technology highlights a significant and promising route for selective synthesis of valuable N-alkylated fine chemicals and pharmaceuticals from nitroarenes and amines with water and alkanols.

Recent advances in visible-light photocatalytic deuteration reactions

The recent advances in visible-light photocatalytic deuteration of X–H, C–halogen, CC, and other bonds for the synthesis of deuterium-labeled organic molecules have been summarized according to the type of bond deuterated in the reactions.

Visible-light-promoted thiocyanation of sp2 C–H bonds over heterogeneous graphitic carbon nitrides

Mesoporous graphitic carbon nitride (mpg-C₃N₄) is developed as a practical heterogeneous photocatalyst for C–S bond formation.