Biobased diamines are excellent precursors for the synthesis of non-isocyanate polyurethanes (NIPUs). The diamines can be reacted with carbonates to access hydroxyalkylcarbamates in good yields of around 80%. We have also developed a method for accessing biscarbamates directly from dialdehydes in good to high yields (70-94%). The hydroxyalkylcarbamates and biscarbamates are valuable precursors of polyurethanes via a phosgene-free route.

The Mukaiyama-Michael (M-M) reaction is a powerful approach for carbon-carbon bond formation and can provide access to all-carbon quaternary centers and vicinal stereocenters. The use of chiral catalysts for this transformation has enabled the development of efficient asymmetric methods in which the reaction proceeds with high enantioselectivity in the presence of only a substoichiometric amount of the chiral promoter. Both chiral Lewis acid catalysts and organocatalysts have been employed. These catalytic methods have afforded improvements in reactivity, selectivity, and substrate scope for the M-M reaction and have enabled the synthesis of complex molecular targets including natural products. In this review, enantioselective M-M methods are surveyed along with their applications in the total synthesis of natural products.

We demonstrated the applicability of two vanillin-derived veratrole monomers, 4-vinyl veratrole (VV) and 3-allyl-5-vinyl veratrole (AVV), as reactive diluents for stereolithography (SLA). As structural analogues of styrene, these nonvolatile biobased monomers enable expanding the applications of styrenics to photocurable systems. Both monomers reduced the viscosity of a commercial oligomeric urethane acrylate resin to the levels acceptable for high-resolution SLA three-dimensional (3D) printing. Compared to two petrochemical controls, 2-phenoxyethyl acrylate and N-vinylpyrrolidone, the veratrole monomers required higher laser exposure to polymerize but allowed achieving high conversion of styrenic double bonds in the SLA process. Participation of the allyl group of AVV in polymerization increased the cross-link density of the 3D printed material, resulting in improved thermal stability and strength characteristics, whereas the VV-containing formulation yielded samples with superior ductility and toughness. Both vanillin-derived monomers demonstrated a significant advantage over 2-phenoxyethyl acrylate, a commercial aromatic diluent, in the thermomechanical properties of the printed materials. Furthermore, VV-based materials had higher elongation at break than the high-performing N-vinylpyrrolidone-containing formulation, whereas AVV showed superior Young's modulus. We expect that the performance demonstrated by the veratrole monomers will accelerate the introduction of biobased styrenics into SLA resin formulations.

Biomass-based diols have been synthesized by a Zn/Bi-mediated Barbier-type of reaction from furanic aldehydes and allyl halides to access allylated diols. The allylated diols can be readily converted into alkylated diols by hydrogenation. These furanic diols could be potential replacements for fossil fuel based bisphenol A (BPA) which has an adverse endocrine-disrupting effect on humans. This mild and green protocol provides symmetric and nonsymmetric diols in high yields. A chemoselective reduction of allylic double bonds provides diols with unique substitution.

Acrylic monomer from high oleic soybean oil (HO-SBM) was combined with vanillin-derived aromatic counterpart, 2-glycidoxy-5-vinylanisole (GVA), in chain copolymerization to design tough biobased thermosets with a dual-curing capability. Under specified conditions, a polymer network can be formed by selective cross-linking of epoxy groups of GVA or HO-SBM allylic groups as well as dual-curing via epoxy-amine and autoxidation mechanisms simultaneously. Glass transition temperature of the synthesized copolymers increases with the GVA content, although the values fall in a rather narrow range (-10 degrees C to 7 degrees C). Thermosets cured via epoxy-amine and dual-curing have a significantly denser network when compared to autooxidation. Such an increase in cross-link density led to improved chemical (solvent) resistance and hardness of thermoset coatings. At the same time, a higher GVA fraction in the chain (from 37 to 44 wt%) noticeably increases Young's modulus of thermosets (up to 235 MPa). A substantial modulus increase at the rubbery plateau was observed for epoxy-amine and dual-curing thermosets with 44 wt% of GVA.

The substantial environmental issues associated with plastic production have prompted researchers to accelerate the development of environmentally friendly biobased alternatives to reduce reliance on petroleum-based resources and mitigate emissions. Epoxidized Sucrose Soyate (ESS), a high-performance biobased epoxy resin obtained from soybean oil and sucrose, has shown promising potential in polymers and coatings applications. The success of ESS performance necessitates further investigations into its industrial-scale production and viability as an environmentally sustainable alternative to conventional petroleum-based resins. This study consists of a comprehensive techno-economic analysis (TEA) and cradle-to-gate life cycle assessment (LCA) to evaluate the technical, economic, and environmental feasibility of industrial-scale ESS production. The minimum selling price (MSP) of ESS at various production scales was estimated which offers insights into cost optimization. The MSP for 0.1, 1.0, and 10 ton/h processing capacity of sucrose soyate was calculated to be $9.57, $6.74, and $6.62 per kg of ESS, respectively. Relative to a comparable petroleum-based epoxy resin with similar functionality, such as bisphenol A diglycidyl ether (with a price range of $1.8 to $5.2 per kg), larger scales of ESS production have the potential to compete economically. The LCA results demonstrated the superior environmental performance of ESS, especially in the global warming potential category, indicating its potential as a compelling sustainable choice for replacing petroleum-based resins. This combined TEA and LCA study demonstrated the economic viability and environmental benefits of ESS, highlighting its promise as a sustainable alternative for industrial applications.

Biobased, DNA delivery vectors have been synthesized with a core motif composed of 2,5-bishydroxymethylfuran (BHMF) readily available from an important biomass feedstock 5-hydroxymethyl furfural (HMF). To generate the product, BHMF was first converted to 2,5-furan bishydroxymethyl diacrylate (2,5-FDA), which was later conjugated with different types of secondary amines. Rich in tertiary nitrogen, these oligomeric FDA-amino esters demonstrated stable electrostatic interactions with negatively charged plasmid DNA in an aqueous environment. We evaluated synthetic routes toward these plasmid DNA-binding amino esters (pFASTs), identified their nanoscale features, and attempted to establish their structure-property relationship in the context of the DNA delivery. Our preliminary studies show that the pFASTs formed stable complexes with the plasmid DNA. Dynamic light scattering indicated that the DNA polyplexes of pFASTs have hydrodynamic diameters within the size range of 100-150 nm with a surface charge (zeta-potential) ranging from -10 to +33 mV, depending on pFAST type. These oligomeric amino esters rich in furan motif were also found to successfully transfect the GFP-expressing plasmid DNA intracellularly. Collectively, this study establishes a new route to produce DNA transfection agents from sustainable resources that can be used for transferring genetic materials for humans, veterinary, and agrochemical purposes. Derived from furan diacrylate, the first examples of biobased gene transfection agents.

Glycidyl ethers are prepared from a series of furan-based diols and cured with a diamine to form thermosets. The furan diols demonstrate lower toxicity than bisphenol-A in a prior study. The diglycidyl ethers show improved thermal stability compared to the parent diols. Cured thermosets are prepared at elevated temperature using isophorone diamine (IPDA). Glass transition temperatures are in the range of 30-54 degrees C and depend on the structure of the furan diol. Coatings are prepared on steel substrates and show very high hardness, good adhesion, and a range of flexibility. Properties compare favorably with a control based on a bisphenol-A epoxy resin. The study demonstrates that epoxy resins based on furan diols, which have been shown to have lower toxicity than bisphenol-A, can form thermosets having properties comparable to a standard epoxy resin system; and thus, are viable as replacements for bisphenol-A epoxy resins. Furan-based diols with good toxicology profiles are used to make diglycidyl ethers (DGEs); and then, cured using a model diamine to form thermosets, and the thermal and mechanical properties are evaluated. Coatings based on the DGEs have properties comparable to that of a bisphenol-A based epoxy resin, showing that these DGEs can be used as non-toxic replacements. image

Enoates derived from alpha-substituted acrylates containing 3-pyrazolidinone achiral template with Bronsted basic fluxional substituents were evaluated in chiral Lewis acid catalyzed enantioselective protonation reactions. The tandem 1,4-conjuagte addition/enantioselective protonation reaction catalyzed by chiral Lewis acids was found to depend on the fluxional group present on the achiral template. The enantioselectivity of the protonation step is highly dependent on the position of the Bronsted basic atom with respect to the pyrazolidinone nitrogen. A comparison of fluxional substituents without a Bronsted basic site and their impact on selectivity is also reported here. The results we detail here are in sharp contrast to our previous studies on enantioselective conjugate addition of malononitriles. The reaction showed reasonable substrate scope for varying alpha-substitution. The reactions gave conjugate adducts in good yields and good enantioselectivities up to 83 %.

The molecular structure of a polymer is a key determinant of the properties and thus potential applications of the bulk material. The presence of acetal functional groups in a polymer can impart advantageous characteristics such as reprocessability, degradability, and recyclability. Many biobased monomers contain functional groups amenable to acetal formation, and a variety of polyacetals have been synthesized from renewable starting materials. These polymers range from elastomers to rigid materials, with their diverse mechanical properties depending on both the acetal units and other structural features of the polymers. A partially biobased poly(acetal-ester) with the trade name Akestra is commercially available and can be used in food packaging applications. In this review, the synthesis and properties of biobased polyacetals are surveyed with an emphasis on the sustainability advantages offered by these materials. A brief overview of polythioacetals, the sulfur analogs of polyacetals, is also included.

A modular route toward the synthesis of P,N ligands containing a fluxional group along the pyrazoline ring core is described. The racemic ligands were accessed in three steps from commercially available fluoroacetophenone in overall yields ranging from 18 to 76%. The enantiopure ligands were obtained using semi-preparative chiral high-performance liquid chromatography and chiral enantioselective phase-transfer catalysis. The effectiveness of the new ligands was assessed in palladium-catalyzed allylic alkylation with diphenylpropenyl acetate and dimethylpropenyl acetate. Under optimized conditions, diphenylpropenyl acetate underwent alkylation with dimethyl malonate in 98% yield and 94% ee. In general, the enantioselectivity for the product correlates with the size of the ligand fluxional group; the larger the fluxional group, the higher the selectivity.

This review presents a comprehensive overview of the synthesis of cyclopropanes using enantioselective Michael Initiated Ring Closure (MIRC) reactions. Cyclopropane-containing compounds possess unique structural and chemical properties that render them valuable in various fields, such as medicine, agrochemistry, and materials science. The MIRC approach has emerged as a versatile and efficient method for generating cyclopropane rings with excellent enantioselectivity. The review details fundamental concepts, reaction mechanisms, and synthetic strategies employed in MIRC reactions. A short introduction is provided to highlight the use of chiral substrates and nucleophiles to synthesize enantioenriched cyclopropanes. Additionally, recent advancements, challenges, and future prospects in the field are also discussed. This review serves as a valuable resource for researchers and practitioners interested in harnessing the potential of MIRC reactions for the synthesis of chiral cyclopropane derivatives, offering a comprehensive and up-to-date overview of the subject matter. This review presents a comprehensive overview of the synthesis of cyclopropanes using enantioselective Michael Initiated Ring Closure (MIRC) reactions.

Chemical structure (effect of functional substituents on vinyl bond reactivity) was used as a criterion to evaluate the (co)polymerization behavior of vanillin-derived 3-allyl-5-vinylveratrole, 4-vinylveratrole, and 2-glycidoxy-5vinylanisole in chain-growth polymerization mechanism. After polymerization, allyl and epoxy functional groups of monomer units remain unaffected as macromolecular side groups and can be utilized in post-polymerization reactions (in particular, cross-linking). Due to the intermolecular chain transfer to polymer, a fraction of branched macromolecules can be formed in free radical polymerization of 3-allyl-5-vinylveratrole. At the same time, the kinetic study shows a similar polymerization rate for all the three investigated biobased aromatic vinyl monomers. Determined in copolymerization with methyl methacrylate Q-e values indicate that 3-allyl-5-vinylveratrole, 4vinylveratrole and 2-glycidoxy-5-vinylanisole behave like conventional vinyl monomers and can be copolymerized interchangeably. In this manner, macromolecules with controlled amounts of cross-linkable epoxy and allyl groups incorporated into the backbone can be synthesized. Based on the glass transition temperature of the homopolymers thereof (66-93 degrees C), biobased aromatic vinyl monomers can serve as "rigid" macromolecular fragments and be applied in the formulation of thermoset polymer coatings. Being derived from renewable resources, 3-allyl-5-vinylveratrole, 4-vinylveratrole, and 2-glycidoxy-5-vinylanisole can be considered as a replacement for petroleum-based commodity styrene in the production of various industrial polymeric materials that utilize aromatic monomers.

Tetralone and its derivatives are unique structural motifs found in a wide range of natural products and serve as key scaffolds for the development of new drugs that target various biological end points. The tetralones have received a lot of interest because of their chemical features and their potential as lead molecules in the pharmaceutical sector. The goal of this review is to present the total synthesis of natural products bearing the 1-tetralone subunit, as well as to highlight key transformations for the synthesis of 1-tetralone. It summarizes the total syntheses of several natural products containing the tetralone subunit, such as 10-norparvulenone, catalponol, aristelegone-A, perenniporide A, and actinoranone.

Hydrogen atom transfer (HAT) is one of the important class of radical reactions. Although extensive research into this elementary step has resulted in the discovery of many compounds capable of functioning as HAT reagents, synthetic methods available to control the stereoselectivity of the HAT process remains challenging. This mini review outlines how small molecule chiral HAT reagents and catalysts were used to achieve stereoselectivity (diastereoselectivity and enantioselectivity) in free radical reactions. The review also focuses on the recent surge in photoenzymatic catalysis to achieve efficient HAT reactions.

We have successfully demonstrated the capability of six bioderived furanic (meth)acrylates to perform as reactive diluents in stereolithography resin compositions. Produced from 5-hydroxymethylfurfural, a biobased platform chemical, via a series of simple transformations, the furanic diluents can reduce the viscosity of commercial stereolithography resins, participate in photocuring with high conversion of polymerizable groups, and satisfy performance requirements. Compared to 1,6-hexanediol diacrylate, a widely used petroleum-based difunctional diluent, several furanic acrylate and methacrylate monomers offer significantly improved thermal and mechanical properties (glass transition temperature, Young's modulus, tensile strength, tensile, and fracture toughness). Incorporating a long n-butyl substituent as a side chain into the diluent structure increases the fracture strain of the 3D printed samples compared to the unsubstituted counterpart but causes a reduction in strength, glass transition temperature, and thermal stability. Using an allyl group as a side chain improves the cross-link density of the system but increases brittleness. Of the six furanic diluents, 2,5-bis(hydroxymethyl)tetrahydrofuran diacrylate and 2,5-bis(hydroxymethyl)furan dimethacrylate demonstrated the best combination of properties. After the necessary optimization, the production of furanic (meth)acrylates has the potential to become more sustainable than the manufacturing of 1,6-hexanediol diacrylate. The potential for sustainability and the high performance of the biobased furanic monomers make them promising alternatives to petroleum-derived components in sustainable stereolithography resin compositions.

A novel monomer, 2-eugenoloxy ethyl vinyl ether (EEVE), was produced from a renewable bio-based compound, eugenol. EEVE was homopolymerized and copolymerized with cyclohexyl vinyl ether (CHVE) via carbocationic polymerization to produce linear polymers. These eugenol-based polymers were evaluated for their ability to produce alkyd-type surface coatings via autoxidative crosslinking. The EEVE-based polymers can provide several advantages over conventional air-drying alkyd resins such as energy-efficient polymerization, precise control over composition and molar mass, and elimination of issues associated with gelation during polymerization. The EEVE-based coatings showed significantly higher chemical resistance, hardness, glass transition temperature, and Young's modulus compared to a commercial alkyd coating. The base resistance of EEVE-based coatings was significantly improved compared to conventional air-drying alkyd resins. As expected, incorporation of the CHVE to the poly(vinyl ether) polymer backbone significantly increased the glass transition temperature and mechanical properties of the crosslinked networks. The optimum physical and thermomechanical properties for the EEVE/CHVE copolymers were obtained at 25 wt% loading of CHVE monomer. Overall, the results of the study suggest a high potential for these eugenol-derived biobased monomers and polymers for applications in airdrying coatings.

Benefiting from the impressive increase in fundamental knowledge, the last 20 years have shown a continuous burst of new ideas and consequently a plethora of new catalytic methods for enantioselective radical reactions. This review aims to provide a complete survey of progress achieved over this latter period. The first part of this review focuses on the use of chiral organocatalysts, and these include catalysts covalently linked to the substrate and those that interact with the substrate by weaker interactions like hydrogen bonds. The second part of the review is devoted to transition-metal redox catalysis which is organized according to increasing atomic number for the first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- and iron-mediated hydroxylations and oxidations are also discussed. A specific section is dedicated to the reactivity of Ru, Rh, and Ir complexes as Lewis acids with a special focus on complexes chiral at metal. Absorption of photons result in different events such as energy transfer, single-electron transfer, and hydrogen-atom transfer facilitating the formation of radicals. Organocatalysis has been successfully combined with photocatalysts, a reactivity which has opened new pathways enlarging the number of radical precursors available. The merger of photocatalysis with organo- or metalla-photocatalysis has brought novelty and allowed for the discovery of a large number of original transformations. The use of enzyme-catalyzed reactions involving radical intermediates which also largely benefit from visible-light irradiation are included in the review. This review provides a comprehensive inventory of progress in enantioselective radical reactions with a goal of detailing the reaction mechanisms involved in these transformations such that any nonspecialist could find their own creativity to invent yet unknown applications.

Photodegradable, recyclable, and renewable, crosslinked polymers from bioresources show promise towards developing a sustainable strategy to address the issue of plastics degradability and recyclability. Photo processes are not widely exploited for upcycling polymers in spite of the potential to have spatial and temporal control of the degradation in addition to being a green process. In this report we highlight a methodology in which biomass-derived crosslinked polymers can be programmed to degrade at ≈300 nm with ≈60 % recovery of the monomer. The recovered monomer was recycled back to the crosslinked polymer.

[34822-90-9] C5H5Tl (MW 269.48) InChI = 1S/C5H5.Tl/c1-2-4-5-3-1;/h1-5H; InChIKey = RKLJDPOVAWGBSD-UHFFFAOYSA-N (cyclopentadienyl ligand) Physical Data: mp >300 °C. Solubility: sol organic solvents. Form Supplied in: light yellow solid readily prepared from thallium hydroxide and dicyclopentadiene2; commercially available. Drying: purified by sublimation. Handling, Storage, and Precautions: stable for several months if stored under nitrogen in a Schlenk flask kept in the dark. All thallium compounds are extremely toxic to inhalation, skin contact, and ingestion. Toxicity is cumulative. Extreme caution should be used when handling these materials. Use in a fume hood.