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Search for "sustainable organic synthesis" in Full Text gives 6 result(s) in Beilstein Journal of Organic Chemistry.
When metal-catalyzed C–H functionalization meets visible-light photocatalysis
- Lucas Guillemard and
- Joanna Wencel-Delord
Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147
- Lucas Guillemard Joanna Wencel-Delord Laboratoire d’Innovation Moléculaire et Applications (UMR CNRS 7042), Université de Strasbourg/Université de Haute-Alsace, ECPM, 25 rue Becquerel, 67087, Strasbourg, France 10.3762/bjoc.16.147 Abstract While aiming at sustainable organic synthesis, over the
- complementary reactivities, the combination of these two activation modes could provide new solutions for sustainable organic synthesis. Indeed, new mutlicatalysis concepts have emerged recently and enabled the achievement of various yet unfeasible reactions [47]. Following this general goal, synergistic
Graphical Abstract
Figure 1: Concept of dual synergistic catalysis.
Figure 2: Classification of catalytic systems involving two catalysts.
Figure 3: General mechanism for the dual nickel/photoredox catalytic system.
Figure 4: General mechanisms for C–H activation catalysis involving different reoxidation strategies.
Figure 5: Indole synthesis via dual C–H activation/photoredox catalysis.
Figure 6: Proposed mechanism for the indole synthesis via dual catalysis.
Figure 7: Oxidative Heck reaction on arenes via the dual catalysis.
Figure 8: Proposed mechanism for the Heck reaction on arenes via dual catalysis.
Figure 9: Oxidative Heck reaction on phenols via the dual catalysis.
Figure 10: Proposed mechanism for the Heck reaction on phenols via dual catalysis.
Figure 11: Carbazole synthesis via dual C–H activation/photoredox catalysis.
Figure 12: Proposed mechanism for the carbazole synthesis via dual catalysis.
Figure 13: Carbonylation of enamides via the dual C–H activation/photoredox catalysis.
Figure 14: Proposed mechanism for carbonylation of enamides via dual catalysis.
Figure 15: Annulation of benzamides via the dual C–H activation/photoredox catalysis.
Figure 16: Proposed mechanism for the annulation of benzamides via dual catalysis.
Figure 17: Synthesis of indoles via the dual C–H activation/photoredox catalysis.
Figure 18: Proposed mechanism for the indole synthesis via dual catalysis.
Figure 19: General concept of dual catalysis merging C–H activation and photoredox catalysis.
Figure 20: The first example of dual catalysis merging C–H activation and photoredox catalysis.
Figure 21: Proposed mechanism for the C–H arylation with diazonium salts via dual catalysis.
Figure 22: Dual catalysis merging C–H activation/photoredox using diaryliodonium salts.
Figure 23: Direct arylation via the dual catalytic system reported by Xu.
Figure 24: Direct arylation via dual catalytic system reported by Balaraman.
Figure 25: Direct arylation via dual catalytic system reported by Guo.
Figure 26: C(sp3)–H bond arylation via the dual Pd/photoredox catalytic system.
Figure 27: Acetanilide derivatives acylation via the dual C–H activation/photoredox catalysis.
Figure 28: Proposed mechanism for the C–H acylation with α-ketoacids via dual catalysis.
Figure 29: Acylation of azobenzenes via the dual catalysis C–H activation/photoredox.
Figure 30: C2-acylation of indoles via the dual C–H activation/photoredox catalysis.
Figure 31: Proposed mechanism for the C2-acylation of indoles with aldehydes via dual catalysis.
Figure 32: C2-acylation of indoles via the dual C–H activation/photoredox catalysis.
Figure 33: Perfluoroalkylation of arenes via the dual C–H activation/photoredox catalysis.
Figure 34: Proposed mechanism for perfluoroalkylation of arenes via dual catalysis.
Figure 35: Sulfonylation of 1-naphthylamides via the dual C–H activation/photoredox catalysis.
Figure 36: Proposed mechanism for sulfonylation of 1-naphthylamides via dual catalysis.
Figure 37: meta-C–H Alkylation of arenes via visible-light metallaphotocatalysis.
Figure 38: Alternative procedure for meta-C–H alkylation of arenes via metallaphotocatalysis.
Figure 39: Proposed mechanism for meta-C–H alkylation of arenes via metallaphotocatalysis.
Figure 40: C–H borylation of arenes via visible-light metallaphotocatalysis.
Figure 41: Proposed mechanism for C–H borylation of arenes via visible-light metallaphotocatalysis.
Figure 42: Undirected C–H aryl–aryl cross coupling via dual gold/photoredox catalysis.
Figure 43: Proposed mechanism for the undirected C–H aryl–aryl cross-coupling via dual catalysis.
Figure 44: Undirected C–H arylation of (hetero)arenes via dual manganese/photoredox catalysis.
Figure 45: Proposed mechanism for the undirected arylation of (hetero)arenes via dual catalysis.
Figure 46: Photoinduced C–H arylation of azoles via copper catalysis.
Figure 47: Photo-induced C–H chalcogenation of azoles via copper catalysis.
Figure 48: Decarboxylative C–H adamantylation of azoles via dual cobalt/photoredox catalysis.
Figure 49: Proposed mechanism for the C–H adamantylation of azoles via dual catalysis.
Figure 50: General mechanisms for the “classical” (left) and Cu-free variant (right) Sonogoshira reaction.
Figure 51: First example of a dual palladium/photoredox catalysis for Sonogashira-type couplings.
Figure 52: Arylation of terminal alkynes with diazonium salts via dual gold/photoredox catalysis.
Figure 53: Proposed mechanism for the arylation of terminal alkynes via dual catalysis.
Figure 54: C–H Alkylation of alcohols promoted by H-atom transfer (HAT).
Figure 55: Proposed mechanism for the C–H alkylation of alcohols promoted by HAT.
Figure 56: C(sp3)–H arylation of latent nucleophiles promoted by H-atom transfer.
Figure 57: Proposed mechanism for the C(sp3)–H arylation of latent nucleophiles promoted by HAT.
Figure 58: Direct α-arylation of alcohols promoted by H-atom transfer.
Figure 59: Proposed mechanism for the direct α-arylation of alcohols promoted by HAT.
Figure 60: C–H arylation of amines via dual Ni/photoredox catalysis.
Figure 61: Proposed mechanism for the C–H arylation of amines via dual Ni/photoredox catalysis.
Figure 62: C–H functionalization of nucleophiles via excited ketone/nickel dual catalysis.
Figure 63: Proposed mechanism for the C–H functionalization enabled by excited ketones.
Figure 64: Selective sp3–sp3 cross-coupling promoted by H-atom transfer.
Figure 65: Proposed mechanism for the selective sp3–sp3 cross-coupling promoted by HAT.
Figure 66: Direct C(sp3)–H acylation of amines via dual Ni/photoredox catalysis.
Figure 67: Proposed mechanism for the C–H acylation of amines via dual Ni/photoredox catalysis.
Figure 68: C–H hydroalkylation of internal alkynes via dual Ni/photoredox catalysis.
Figure 69: Proposed mechanism for the C–H hydroalkylation of internal alkynes.
Figure 70: Alternative procedure for the C–H hydroalkylation of ynones, ynoates, and ynamides.
Figure 71: Allylic C(sp3)–H activation via dual Ni/photoredox catalysis.
Figure 72: Proposed mechanism for the allylic C(sp3)–H activation via dual Ni/photoredox catalysis.
Figure 73: Asymmetric allylation of aldehydes via dual Cr/photoredox catalysis.
Figure 74: Proposed mechanism for the asymmetric allylation of aldehydes via dual catalysis.
Figure 75: Aldehyde C–H functionalization promoted by H-atom transfer.
Figure 76: Proposed mechanism for the C–H functionalization of aldehydes promoted by HAT.
Figure 77: Direct C–H arylation of strong aliphatic bonds promoted by HAT.
Figure 78: Proposed mechanism for the C–H arylation of strong aliphatic bonds promoted by HAT.
Figure 79: Direct C–H trifluoromethylation of strong aliphatic bonds promoted by HAT.
Figure 80: Proposed mechanism for the C–H trifluoromethylation of strong aliphatic bonds.
Heterogeneous photocatalysis in flow chemical reactors
- Christopher G. Thomson,
- Ai-Lan Lee and
- Filipe Vilela
Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125
- irradiation. Herein, we review some important developments of heterogeneous photocatalytic materials and their application in flow reactors for sustainable organic synthesis. Further, the application of continuous flow heterogeneous photocatalysis in environmental remediation is briefly discussed to present
Graphical Abstract
Figure 1: A) Bar chart of the publications per year for the topics “Photocatalysis” (49,662 instances) and “P...
Figure 2: A) Professor Giacomo Ciamician and Dr. Paolo Silber on their roof laboratory at the University of B...
Scheme 1: PRC trifluoromethylation of N-methylpyrrole (1) using hazardous gaseous CF3I safely in a flow react...
Figure 3: A) Unit cells of the three most common crystal structures of TiO2: rutile, brookite, and anatase. R...
Figure 4: Illustration of the key semiconductor photocatalysis events: 1) A photon with a frequency exceeding...
Figure 5: Photocatalytic splitting of water by oxygen vacancies on a TiO2(110) surface. Reprinted with permis...
Figure 6: Proposed adsorption modes of A) benzene, B) chlorobenzene, C) toluene, D) phenol, E) anisole, and F...
Figure 7: Structures of the sulfonate-containing organic dyes RB5 (3) and MX-5B (4) and the adsorption isothe...
Figure 8: Idealised triclinic unit cell of a g-C3N4 type polymer, displaying possible hopping transport scena...
Figure 9: Idealised structure of a perfect g-C3N4 sheet. The central unit highlighted in red represents one t...
Figure 10: Timeline of the key processes of charge transport following the photoexcitation of g-C3N4, leading ...
Scheme 2: Photocatalytic bifunctionalisation of heteroarenes using mpg-C3N4, with the selected examples 5 and ...
Figure 11: A) Structure of four linear conjugated polymer photocatalysts for hydrogen evolution, displaying th...
Figure 12: Graphical representation of the common methods used to immobilise molecular photocatalysts (PC) ont...
Figure 13: Wireless light emitter-supported TiO2 (TiO2@WLE) HPCat spheres powered by resonant inductive coupli...
Figure 14: Graphical representation of zinc–perylene diimide (Zn-PDI) supramolecular assembly photocatalysis v...
Scheme 3: Upconversion of NIR photons to the UV frequency by NaYF4:Yb,Tm nanocrystals sequentially coated wit...
Figure 15: Types of reactors employed in heterogeneous photocatalysis in flow. A) Fixed bed reactors and the s...
Figure 16: Electrochemical potential of common semiconductor, transition metal, and organic dye-based photocat...
Scheme 4: Possible mechanisms of an immobilised molecular photoredox catalyst by oxidative or reductive quenc...
Scheme 5: Scheme of the CMB-C3N4 photocatalytic decarboxylative fluorination of aryloxyacetic acids, with the...
Scheme 6: Scheme of the g-C3N4 photocatalytic desilylative coupling reaction in flow and proposed mechanism [208].
Scheme 7: Proposed mechanism of the radical cyclisation of unsaturated alkyl 2-bromo-1,3-dicarbonyl compounds...
Scheme 8: N-alkylation of benzylamine and schematic of the TiO2-coated microfluidic device [213].
Scheme 9: Proposed mechanism of the Pt@TiO2 photocatalytic deaminitive cyclisation of ʟ-lysine (23) to ʟ-pipe...
Scheme 10: A) Proposed mechanism for the photocatalytic oxidation of phenylboronic acid (24). B) Photos and SE...
Scheme 11: Proposed mechanism for the DA-CMP3 photocatalytic aza-Henry reaction performed in a continuous flow...
Scheme 12: Proposed mechanism for the formation of the cyclic product 32 by TiO2-NC HPCats in a slurry flow re...
Scheme 13: Reaction scheme for the photocatalytic synthesis of homo and hetero disulfides in flow and scope of...
Scheme 14: Reaction scheme for the MoOx/TiO2 HPCat oxidation of cyclohexane (34) to benzene. The graph shows t...
Scheme 15: Proposed mechanism of the TiO2 HPC heteroarene C–H functionalisation via aryl radicals generated fr...
Scheme 16: Scheme of the oxidative coupling of benzylamines with the HOTT-HATN HPCat and selected examples of ...
Scheme 17: Photocatalysis oxidation of benzyl alcohol (40) to benzaldehyde (41) in a microflow reactor coated ...
Figure 17: Mechanisms of Dexter and Forster energy transfer.
Scheme 18: Continuous flow process for the isomerisation of alkenes with an ionic liquid-immobilised photocata...
Scheme 19: Singlet oxygen synthetic step in the total synthesis of canataxpropellane [265].
Scheme 20: Scheme and proposed mechanism of the singlet oxygen photosensitisation by CMP_X HPCats, with the st...
Scheme 21: Structures of CMP HPCat materials applied by Vilela and co-workers for the singlet oxygen photosens...
Scheme 22: Polyvinylchloride resin-supported TDCPP photosensitisers applied for singlet oxygen photosensitisat...
Scheme 23: Structure of the ionically immobilised TPP photosensitiser on amberlyst-15 ion exchange resins (TPP...
Scheme 24: Photosensitised singlet oxygen oxidation of citronellol (46) in scCO2, with automatic phase separat...
Scheme 25: Schematic of PS-Est-BDP-Cl2 being applied for singlet oxygen photosensitisation in flow. A) Pseudo-...
Scheme 26: Reaction scheme of the singlet oxygen oxidation of furoic acid (54) using a 3D-printed microfluidic...
Figure 18: A) Photocatalytic bactericidal mechanism by ROS oxidative cleavage of membrane lipids (R = H, amino...
Figure 19: A) Suggested mechanisms for the aqueous pollutant degradation by TiO2 in a slurry flow reactor [284-287]. B)...
Figure 20: Schematic of the flow system used for the degradation of aqueous oxytetracycline (56) solutions [215]. M...
Scheme 27: Degradation of a salicylic acid (57) solution by a coupled solar photoelectro-Fenton (SPEF) process...
Figure 21: A) Schematic flow diagram using the TiO2-coated NETmix microfluidic device for an efficient mass tr...
Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide
- Lu Yang,
- Yuwei Wu,
- Yiming Yang,
- Chengping Wen and
- Jie-Ping Wan
Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210
- , including those reactions involving valuable C–C [7][8][9][10][11], C–heteroatom [12][13][14][15][16], heteroatom–heteroatom [17][18] bond formation as well as divergent cascade reactions [19][20][21][22][23], are presently taking place to guide the progress of sustainable organic synthesis. 1,2,3-Triazole
Graphical Abstract
Figure 1: Scope of the water-mediated synthesis of 4-acyl-NH-1,2,3-triazoles. General conditions: enaminone 1...
Scheme 1: The gram scale synthesis of 3a: (a) before reaction; (b) completed reaction; (c) the purified produ...
Scheme 2: The proposed reaction mechanism.
An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation
- Carolina S. García,
- Paula M. Uberman and
- Sandra E. Martín
Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166
- make this protocol a great option for stilbene syntheses by Mizoroki–Heck reaction. Keywords: aqueous reaction medium; MAOS; Mizoroki–Heck reaction; Pd nanoparticle; sustainable organic synthesis; Introduction Palladium-catalyzed reactions have emerged as an important tool for organic synthesis
Graphical Abstract
Scheme 1: Synthesis of (E)-pterostilbene (19) catalyzed by PVP-Pd NPs.
Figure 1: Reuse experiments of PdNPs in the coupling reaction between 4-bromoacetophenone (1a) and styrene (2a...
Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis
- Flavio Fanelli,
- Giovanna Parisi,
- Leonardo Degennaro and
- Renzo Luisi
Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51
- organic synthesis, very recent examples have been selected and will be discussed here. In the context of green chemistry [11], protecting-group free organic synthesis has received particular attention in the last years, because of atom economy [12][13][14][15] and reduction of synthetic steps [16]. It has
- both organic and sustainable synthesis involving chemical transformations that are very difficult or practically impossible to conduct using conventional batch conditions. With the aim to show how flow microreactor technology and flash chemistry could contribute to the development of a sustainable
Graphical Abstract
Figure 1: Microreactor technologies and flow chemistry for a sustainable chemistry.
Scheme 1: A flow microreactor system for the generation and trapping of highly unstable carbamoyllithium spec...
Scheme 2: Flow synthesis of functionalized α-ketoamides.
Scheme 3: Reactions of benzyllithiums.
Scheme 4: Trapping of benzyllithiums bearing carbonyl groups enabled by a flow microreactor. (Adapted with pe...
Scheme 5: External trapping of chloromethyllithium in a flow microreactor system.
Scheme 6: Scope for the direct tert-butoxycarbonylation using a flow microreactor system.
Scheme 7: Control of anionic Fries rearrangement reactions by using submillisecond residence time. (Adapted w...
Figure 2: Chip microreactor (CMR) fabricated with six layers of polyimide films. (Reproduced with permission ...
Scheme 8: Flow microreactor system for lithiation, borylation, Suzuki–Miyaura coupling and selected examples ...
Scheme 9: Experimental setup for the flow synthesis of 2-fluorobi(hetero)aryls by directed lithiation, zincat...
Scheme 10: Experimental setup for the coupling of fluoro-substituted pyridines. (Adapted with permission from [53]...
Scheme 11: Continuous flow process setup for the preparation of 11 (Reproduced with permission from [54], copyrigh...
Scheme 12: Continuous-flow photocatalytic oxidation of thiols to disulfides.
Scheme 13: Trifluoromethylation by continuous-flow photoredox catalysis.
Scheme 14: Flow photochemical synthesis of 6(5H)-phenanthridiones from 2-chlorobenzamides.
Scheme 15: Synthesis of biaryls 14a–g under photochemical flow conditions.
Scheme 16: Flow oxidation of hydrazones to diazo compounds.
Scheme 17: Synthetic use of flow-generated diazo compounds.
Scheme 18: Ley’s flow approach for the generation of diazo compounds.
Scheme 19: Iterative strategy for the sequential coupling of diazo compounds.
Scheme 20: Integrated synthesis of Bakuchiol precursor via flow-generated diazo compounds.
Scheme 21: Kappe’s continuous-flow reduction of olefines with diimide.
Scheme 22: Multi-injection setup for the reduction of artemisinic acid.
Scheme 23: Flow reactor system for multistep synthesis of (S)-rolipram. Pumps are labelled a, b, c, d and e; L...
Figure 3: Reconfigurable modules and flowcharts for API synthesis. (Reproduced with permission from [85], copyrig...
Figure 4: Reconfigurable system for continuous production and formulation of APIs. (Reproduced with permissio...
Selective synthesis of thioethers in the presence of a transition-metal-free solid Lewis acid
- Federica Santoro,
- Matteo Mariani,
- Federica Zaccheria,
- Rinaldo Psaro and
- Nicoletta Ravasio
Beilstein J. Org. Chem. 2016, 12, 2627–2635, doi:10.3762/bjoc.12.259
- wide as other systems only convert propargylic alcohols [30] or benzhydrol and electron-deficient thiols [31] in agreement with the high electrophilicity of these substrates. Conclusion Amorphous solid acid catalysts are very promising materials in the roadmap to green and sustainable organic synthesis
Graphical Abstract
Figure 1: Overview of the structures of the alcohols 1a–i used in the present work.
Figure 2: Structures of thiols 2a–f used in the present work.
Figure 3: Structures of thioethers 3a–p synthesized.
Figure 4: Product distribution during reaction of 5b and 2a over a solid acid catalyst.
Figure 5: Product distribution during reaction of 1c and 2e.
Scheme 1: Racemization of (R)-1-phenylethanol during the reaction with benzylmercaptan (2a) in the presence o...
Scheme 2: Reaction of cinnamyl alcohol 1i and benzylmercaptan (2a).
Figure 6: Recyclability test of SiAl 0.6 catalyst in the reaction of 1a and 2a.
