Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• graphical format in Figure 2 for the glycolysis reaction of PET, using titanium(IV) n-butoxide as the catalyst. Compared to the uncatalysed process, benefits include milder reaction conditions, higher selectivity and productivity and reduced generation of waste; in short, improved sustainability [84][85

• significant formation of decomposition byproducts may be observed (i.e., dioxane and acetaldehyde for DEG [242]). Because of that, these metal-catalysed depolymerisations cannot be strictly considered as selective, although the overall processes are interesting from a practical and sustainability point of

A sustainable strategy for the straightforward preparation of 2H-azirines and highly functionalized NH-aziridines from vinyl azides using a single solvent flow-batch approach

• Michael Andresini,
• Leonardo Degannaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2021, 17, 203–209, doi:10.3762/bjoc.17.20

• the elements that affect the sustainability of a synthetic method, the choice of the solvent is crucial [5]. In fact, chemical solvents represent most of the total amount of chemical species used in manufacturing processes, and therefore, strongly affect waste disposal requirements and process related

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• a stabilizer to control the size and distribution of the NPs and are able to intensely regulate the photocatalytic performance. 5) To improve the sustainability, noble metals need to be replaced by earth-abundant metals. However, in most cases, earth-abundant metals have a lower photocatalytic

An atom-economical addition of methyl azaarenes with aromatic aldehydes via benzylic C(sp³)–H bond functionalization under solvent- and catalyst-free conditions

• Divya Rohini Yennamaneni,
• Vasu Amrutham,
• Krishna Sai Gajula,
• Rammurthy Banothu,
• Murali Boosa and
• Narender Nama

Beilstein J. Org. Chem. 2020, 16, 3093–3103, doi:10.3762/bjoc.16.259

• atom economy and reduces large amounts of waste generated by the unnecessary utilization of catalysts and solvents. Notably, this reaction is compatible with a gram scale, and further research is yet to be developed towards more sustainability. Benzylic addition of aldehydes to azaarenes using

Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction

• Tony Jin,
• Malickah Hicks,
• Davis Kurdyla,
• Sabahudin Hrapovic,
• Edmond Lam and
• Audrey Moores

Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201

• coupling; heterogeneous catalysis; nanomaterial; Introduction Over the past decades, biomass-based nanomaterials have become a highly prevalent topic of research owing to their sustainability, bioavailability, unique structural and morphological characteristics [1]. Particularly dominant in this field are

A proposed sustainability index for synthesis plans based on input provenance and output fate: application to academic and industrial synthesis plans for vanillin as a case study

• John Andraos

Beilstein J. Org. Chem. 2020, 16, 2346–2362, doi:10.3762/bjoc.16.196

• John Andraos CareerChem, 504-1129 Don Mills Road, Toronto, ON, M3B 2W4, Canada 10.3762/bjoc.16.196 Abstract This paper describes a sustainability index (SI) as a quantitative measure of “sustainability” applicable to synthesis plans based on the provenance of input materials and energy sources

• ) consumption, input enthalpic energy (IEE) consumption, Rowan solvent greenness index (RSGI), and sustainability index (SI). Keywords: Borda count; green chemistry; input enthalpic energy; process mass intensity; poset dominance analysis; Rowan solvent greenness index; sacrificial reagent; sustainability

• ; sustainable chemistry; Introduction The words “sustainable” and “sustainability” are nowadays routinely used throughout common speech and the popular press, including published modern chemistry literature, when discussing topics related to pressing issues such as preservation of the environment, climate

Efficient [(NHC)Au(NTf₂)]-catalyzed hydrohydrazidation of terminal and internal alkynes

• Maximillian Heidrich and
• Herbert Plenio

Beilstein J. Org. Chem. 2020, 16, 2080–2086, doi:10.3762/bjoc.16.175

• performance in anisole was comparable to that in chlorobenzene. According to both the CHEM21 consortium and the GSK solvent sustainability guide the use of anisole is highly favorable [48]. To clarify the role of chlorobenzene and anisole, most substrate screening reactions were performed in both solvents

Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions

• Edgar Peris,
• Raúl Porcar,
• María Macia,
• Jesús Alcázar,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159

• complexes enabling a simpler recovery and reuse of the catalysts by filtration [5]. Furthermore, the immobilized NHC-complexes can be easily adapted to flow processes using a fix-bed reactor set-up increasing simultaneously the sustainability and the efficiency of the C–C coupling reactions [6][7]. In the

Stereoselective Biginelli-like reaction catalyzed by a chiral phosphoric acid bearing two hydroxy groups

• Xiaoyun Hu,
• Jianxin Guo,
• Cui Wang,
• Rui Zhang and
• Victor Borovkov

Beilstein J. Org. Chem. 2020, 16, 1875–1880, doi:10.3762/bjoc.16.155

• compound making its application highly attractive from the viewpoint of sustainability and green chemistry. Recently, our group reported an asymmetric Biginelli reaction catalyzed by a new chiral phosphoric acid derived from natural tartaric acid, that yielded a high enantioselectivity (up to 99% ee) [17

Facile synthesis of 7-alkyl-1,2,3,4-tetrahydro-1,8-naphthyridines as arginine mimetics using a Horner–Wadsworth–Emmons-based approach

• Rhys A. Lippa,
• John A. Murphy and
• Tim N. Barrett

Beilstein J. Org. Chem. 2020, 16, 1617–1626, doi:10.3762/bjoc.16.134

• proceeded well (91% isolated yield) in 2-MeTHF, which offers a preferred alternative if the reaction is performed on a larger scale due to better partitioning with water, stability, and sustainability of production [21]. Of the bases trialled, only s-BuLi was efficient in promoting C-phosphorylation

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• (hetero)aromatic rings. Most of the protocols illustrated herein, however, involved the use of rather expensive transition-metal-based (e.g., on Ru or Ir) photocatalysts, that still represents an issue in terms of sustainability. In this context, the use of photoorganocatalysts [24] is a promising

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• , Universitätsstraße 31, 93040 Regensburg, Germany Technical University of Munich, Campus Straubing for Biotechnology and Sustainability, Schulgasse 16, 94315 Straubing, Germany 10.3762/bjoc.16.104 Abstract The preparation of activated carbon materials is discussed along selected examples of precursor materials, of

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• selectivity, sustainability, and environmentally friendly bond constructions. C–H fluoroalkylation of arenes Fluoroalkylations in earlier reported methods required prefunctionalization of arenes, directing groups, etc. [175][176][177][178][179]. In this context, researchers were trying to find alternatives to

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• renaissance by virtue of its greenness, sustainability, atom economy, step economy and inherent safety. Achieving stereocontrol in such organic electrochemical reactions remains a major synthetic challenge and hence demands great expertise. This review provides a comprehensive discussion of the details of

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• description of the bacterial TPS CotB2, we will therefore refer to the NSE motif only. Using host microorganisms, such as bacteria or baker’s yeast for the heterologous synthesis of terpenes increases the sustainability of bioactive terpene production by saving resources, as the production host can be fed

Naphthalene diimides with improved solubility for visible light photoredox catalysis

• Barbara Reiß and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 2043–2051, doi:10.3762/bjoc.15.201

• light range between 520 nm and 640 nm. The irradiation by visible light together with the use of an organic dye instead of a transition metal complex as photoredox catalyst improve the sustainability and make photoredox catalysis “greener”. Keywords: chromophore; dyes; electrochemistry; photochemistry

• sustainability further, organic compounds, mainly eosin Y [25], rhodamine 6G [26], 9-mesityl-10-methylacridinium perchlorate [27], 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzenes [28] and N-phenylphenothiazines [29] were applied as important alternative photoredox catalysts [30][31]. These studies

• photoredox catalyst improve the sustainability and make photoredox catalysis “greener”. Experimental All experimental details are described in the Supporting Information File 1. Optical properties of NDI 1 and cNDIs 2 and 6: UV–vis absorbance in CH2Cl2 and in DMF (normal lines), normalized fluorescence in

Multicomponent reactions III

• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1974–1975, doi:10.3762/bjoc.15.192

• Thomas J. J. Muller Heinrich-Heine Universität Düsseldorf, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstraße 1, D-40225 Düsseldorf, Germany 10.3762/bjoc.15.192 Keywords: MCR; multicomponent reactions; In times of steadily increasing relevance of sustainability and

Metal-free mechanochemical oxidations in Ertalyte^® jars

• Andrea Porcheddu,
• Francesco Delogu,
• Lidia De Luca,
• Claudia Fattuoni and
• Evelina Colacino

Beilstein J. Org. Chem. 2019, 15, 1786–1794, doi:10.3762/bjoc.15.172

• (OAc)2, I2, CAN, etc.) has been intensively investigated with varying results in terms of yields, chemical selectivity, and environmental sustainability [10][11][12][13][14][15][16][17][18]. All oxidation procedures have their advantages and their flaws, so the search for efficient, selective, high

• on a mechanochemical activation [28]. In comparison to solution-based techniques, ball-milling procedures provide an ideal solution for overcoming many of the drawbacks described above, due to the simplicity of use, shorter reaction times, large-scale production, low cost and sustainability of this

Enantioselective PCCP Brønsted acid-catalyzed aza-Piancatelli rearrangement

• Gabrielle R. Hammersley,
• Meghan F. Nichol,
• Helena C. Steffens,
• Jose M. Delgado,
• Gesine K. Veits and
• Javier Read de Alaniz

Beilstein J. Org. Chem. 2019, 15, 1569–1574, doi:10.3762/bjoc.15.160

• Sustainability for a fellowship in support of this research. J. M. D. thanks the McNair Foundation for support.

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

• synthesis of 4-acyl-NH-1,2,3-triazoles has been accomplished with high efficiency through the cycloaddition reactions between N,N-dimethylenaminones and tosyl azide. This method is featured with extraordinary sustainability by employing water as the sole medium, free of any catalyst or additive

• present method benefits from unique sustainability not only due to the metal/additive-free cycloaddition reaction, but also by applying the completely green reaction medium water and mild reaction temperature. Scope of the water-mediated synthesis of 4-acyl-NH-1,2,3-triazoles. General conditions

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• pharmaceutical industry. This type of chemistry has also demonstrated a high degree of sustainability, especially when organic dyes can be employed in place of often toxic and environmentally damaging transition metals. The sections are arranged according to the general class of the presented reactions and the

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• iodoarenes, which are released in stoichiometric amounts in any reaction mediated by λ3- or λ5-iodanes. In parallel to the development of solid-supported reagents or reactions catalytic in iodine, a third strategy has emerged to address this issue in terms of sustainability. The atom-economy of

• reactions involving a step that enables the introduction of the iodoarene side-compound into the products. Various sequences combining oxidation reactions, nucleophilic additions, or aromatic couplings, thus, have been reported (Scheme 1b). In addition to address the issue of sustainability, this

• catalytic amount of dimethylethylenediamine. Linear diaryl-λ3-iodanes When compared to cyclic diaryl-λ3-iodanes, the linear analogues inherently raise a more challenging issue to address in terms of sustainability, particularly in the case of non-symmetrical reagents. As mentioned in the introduction, the

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• sustainability and elegancy. Utilizing catalytic nanoreactors for greener reactions, for facilitating multistep synthetic pathways in one-pot procedures, is imperative with far-reaching implications in the field. This review is focused on the applications of some of the most used nanoreactors in catalysis

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

• Fabio Tonin and
• Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

• . An approach that bears great promise is the biotransformation with non-pathogenic, easy-to-manage microorganisms, and their enzymes. Several chemical, chemoenzymatic and enzymatic routes have been proposed for the production of UDCA. In view of sustainability, instead of pursuing a step-wise approach

Mechanochemistry

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 2372–2373, doi:10.3762/bjoc.13.234

• of achieving chemical reactivity under solvent-free conditions. Additionally, the utilization of mechanochemical technology can often further simplify the posterior work-up procedures, having a deeper impact on the sustainability of the global synthetic process (reduction of waste, lower energy