This focused collection of papers is devoted to recent developments in ‘green chemistry’, especially the applications of catalytic methods, involving both chemo- and biocatalysis. The development of catalytic processes is an important current theme in organic chemistry, since it aims to reduce the environmental impact of the industrial synthesis of chemicals and polymers by replacing stoichiometric reagents with catalysts and also exchanging harmful organic solvents with less detrimental alternatives. Green processes can also result in lower costs of goods and starting materials as well as in the use of less harmful and toxic reagents, which delivers benefits in terms of safety and disposal of waste byproducts.
See also the Thematic Series:
Green chemistry
Strategies in asymmetric catalysis
Bifunctional catalysis
Graphical Abstract
Scheme 1: Activated derivatives of dicarboxylic acids.
Figure 1: Example of natural compounds selectively acylated with dicarboxylic esters.
Figure 2: C6-dicarboxylic acid diesters derivatives of NAG-thiazoline.
Figure 3: Sylibin dimers obtained by CAL-B catalyzed trans-acylation reactions.
Scheme 2: Biocatalyzed synthesis of paclitaxel derivatives.
Figure 4: 5-Fluorouridine derivatives obtained by CAL-B catalysis.
Scheme 3: Biocatalyzed synthesis of hybrid diesters 17 and 18.
Scheme 4: Hybrid derivatives of sylibin.
Figure 5: Bolaamphiphilic molecules containing (L)- and/or (D)-isoascorbic acid moieties.
Figure 6: Doxorubicin (29) trapped in a polyester made of glycolate, sebacate and 1,4-butandiol units.
Figure 7: Polyesters containing functionalized pentofuranose derivatives.
Figure 8: Polyesters containing disulfide moieties.
Figure 9: Polyesters containing epoxy moieties.
Figure 10: Biocatalyzed synthesis of polyesters containing glycerol.
Figure 11: Iataconic (34) and malic (35) acid.
Figure 12: Oxidized poly(hexanediol-2-mercaptosuccinate) polymer.
Figure 13: C-5-substituted isophthalates.
Figure 14: Curcumin-based polyesters.
Figure 15: Silylated polyesters.
Figure 16: Polyesters containing reactive ether moieties.
Figure 17: Polyesters obtained by CAL-B-catalyzed condensation of dicarboxylic esters and N-substituted dietha...
Figure 18: Polyesters comprising mexiletine (38) moieties.
Figure 19: Poly(amide-co-ester)s comprising a terminal hydroxy moiety.
Figure 20: Polymer comprising α-oxydiacid moieties.
Figure 21: Telechelics with methacrylate ends.
Figure 22: Telechelics with allyl-ether ends.
Figure 23: Telechelics with ends functionalized as epoxides.
Graphical Abstract
Scheme 1: Synthesis of cyclic and polycarbonates.
Figure 1: Bifunctional aluminium–salen complexes, including those studied in this work.
Scheme 2: Synthesis of salen ligands 8a and 8b.
Scheme 3: The preparation of aluminum complexes 1, 2 and 10.
Scheme 4: Possible formation of a dinuclear complex from 1 by treatment with H2O and Et3N.
Figure 2: MALDI–TOF spectrum of poly(hexene carbonate) prepared using catalyst 2. The peak at 565 Daltons cor...
Figure 3: GPC trace of poly(cyclohexene carbonate) prepared using catalyst 2. The chromatogram was obtained i...
Graphical Abstract
Figure 1: Library generation of P450cam[Tyr96Phe]-RhFRed. Active site of the P450cam-RhFRed variant Tyr96Phe ...
Figure 2: Radar plots illustrating the substrate acceptance of P450cam-RhFRed variants from library I. Colour...
Figure 3: Yields of alcohols (R,S)-9-11 (grey bars) and ketone products 13–15 (blue bars) in sub-pools of lib...
Graphical Abstract
Figure 1: Simplified schematic representation of the methanol utilization pathway in Pichia pastoris. The mai...
Figure 2: Representation of the genomic region coding for dihydroxyacetone synthases. The DAS1 and DAS2 codin...
Figure 3: Relative expression levels of the green fluorescent protein (GFP) in the das knock-out strains. GFP...
Figure 4: BDH1-based whole-cell conversions of rac-acetoin. (A) Conversions of 25 mM rac-acetoin in the diffe...
Graphical Abstract
Graphical Abstract
Figure 1: Biocatalytic routes for conversion of CO2 into compounds with carbon in the reduced oxidation state...
Figure 2: Carbonic anhydrase-catalysed rapid interconversion of CO2 and HCO3− in living systems.
Scheme 1: The Calvin cycle for fixation of CO2 with RuBisCO.
Scheme 2: The reductive TCA cycle with CO2 fixation enzymes designated.
Scheme 3: The Wood–Ljungdahl pathway for generation of acetyl-CoA through reduction of CO2 to formate and CO....
Scheme 4: The acyl-CoA carboxylase pathways for autotrophic CO2 fixation. ACC: acetyl-CoA/propionyl-CoA carbo...
Figure 3: RuBisCO CO2-fixing bypass installed in E. coli and S. cerevisiae to increase carbon flux toward pro...
Scheme 5: Integrated biocatalytic system for carboxylation of phosphoenolpyruvate (19), using PEPC and carbon...
Scheme 6: PEPC and pyruvate carboxylase catalysed carboxylation of pyruvate backbone for the generation of ox...
Scheme 7: Decarboxylase catalysed carboxylation of (a) phenol derivatives, (b) indole and (c) pyrrole.
Figure 4: Formate dehydrogenase (FDH) catalysed reversible reduction of CO2 to formate with electron donor re...
Figure 5: Sequential generation of formate, formaldehyde and methanol from CO2 using reducing equivalents sou...
Figure 6: Hydrogen storage as formic acid through biocatalytic hydrogenation of CO2 and subsequent on-demand ...
Figure 7: Schematic showing required flow of reducing equivalents for CO2 fixation through biotechnological a...
Graphical Abstract
Scheme 1: Two-phase reaction of N,N-dialkylamine and sodium hypochlorite.
Figure 1: Calorimeter trace for the single phase reaction of morpholine (aq) and NaOCl (aq). Q Comp: compensa...
Figure 2: Meso-scale static mixer set-up for continuous N-chloramine formation. (a) Pumps, (b) reagent soluti...
Figure 3: Effect of static mixers on biphasic solution.
Figure 4: Progress of reaction for continuous formation of N-chloromorpholine. Morpholine (toluene) 0.9 M 1 m...
Figure 5: CSTR set-up for N-chloramine formation. (a) Syringe pump, (b) collection vessels, (c) reactor (50 m...
Figure 6: Interior of 50 mL CSTR.
Graphical Abstract
Figure 1: Examples of naturally-occurring and synthetic bioactive (amidoalkyl)pyridines.
Scheme 1: Discovery of the azlactone arylation/decarboxylative hydrolysis approach to 2-(1-amidoalkyl)pyridin...
Scheme 2: Substrate scope of the direct amidoalkylation of pyridine N-oxides.
Graphical Abstract
Figure 1: Hydrogen–deuterium exchange through acid-catalyzed imine–enamine tautomerization of 3h (0.5 M) and ...
Scheme 1: Benzylic oxygenation of benzoannulated azines and diazines (5).
Scheme 2: Classical (top) and new formal (bottom) synthesis of Mefloquine.
Scheme 3: Iron-catalyzed aerobic oxidation of papaverine (15).
Graphical Abstract
Figure 1: The immobilization scheme of FDH onto Immobead 150 and modified Immobead 150 supports.
Figure 2: The effect of pH on the activities of free and immobilized FDH preparations. The FDH activity at pH...
Figure 3: The effect of temperature on the activities of free and immobilized FDH preparations. The enzyme ac...
Figure 4: Thermal stability of free and immobilized FDH preparations at 35 °C.
Figure 5: Thermal stability of free and immobilized FDH preparations at 50 °C.
Figure 6: The reusability of immobilized FDHs.