Publications by authors named "Felipe de la Cruz-Martinez"
Article Synopsis
- Novel alkyl zinc complexes with acetamidate/thioacetamidate ligands were synthesized and showed varying coordination modes influenced by their electronic and steric properties.
- These complexes were found to effectively catalyze hydroelementation reactions of alkynyl alcohol/acid substrates, leading to enol ether or unsaturated lactone products under mild conditions.
- Kinetic studies revealed that the reactions are first-order with respect to the catalyst and zero-order in alkynyl substrate, while DFT calculations indicated a mechanism involving an alkoxide-zinc intermediate formed through protonolysis of the Zn-alkyl bond.
Article Synopsis
- The reaction of bis(1,2,3-triazol-1-yl)methane derivatives with BuLi and different aldehydes produced new neutral ligand precursors with alcohol groups.
- The characteristics of these compounds varied based on the steric effects of the aldehydes used, with different functionalization patterns observed.
- The resulting precursors were used to create efficient dinuclear organometallic complexes with aluminum and zinc, which demonstrated potential for catalyzing selective polymerization reactions.
The activation and functionalization of carbon dioxide entails great interest related to its abundance, low toxicity and associated environmental problems. However, the inertness of CO has posed a challenge towards its efficient conversion to added-value products. In this review we discuss one of the strategies that have been widely used to capture and activate carbon dioxide, namely the use of donor-acceptor interactions by partnering a Lewis acidic and a Lewis basic fragment.
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- The text discusses a method for creating new polymer materials by using ring-opening copolymerization with epoxides, carbon dioxide, and cyclic esters.
- New bimetallic chloride indium complexes are introduced as effective catalysts that work well under mild conditions, producing poly(cyclohexene carbonate) without needing a co-catalyst.
- The process allows for adjustable incorporation of carbon dioxide, leading to different copolymer thermal properties depending on the CO pressure and monomer used.
Article Synopsis
- The increasing global population and resource depletion necessitate the development of sustainable materials, particularly from biodegradable and renewable sources.
- Researchers are exploring a "metal-free" copolymerization method to transform biomass-derived carvone into unique luminescent biopolymers.
- The study found that the luminescence characteristics of these copolymers are affected by their structural folding and environment, making them highly sensitive to temperature changes, which could lead to applications in smart photothermal imaging technologies.
Bimetallic motifs mediate the selective activation and functionalization of CO in metalloenzymes and some recent synthetic systems. In this work, we build on the nascent concept of bimetallic frustrated Lewis pairs (FLPs) to investigate the activation and reduction of CO . Using the Fe fragment [(depe) Fe] (depe=1,2-bis(diethylphosphino)ethane) as base, we modify the nature of the partner Lewis acid to accomplish a divergent and highly chemoselective reactivity towards CO .
View Article and Find Full Text PDFA series of Au(I)/Pt(0) combinations that behave as bimetallic frustrated Lewis pairs activates dihydrogen in a cooperative manner. The steric bulk of the terphenyl phosphines that stabilize both fragments allows for the isolation of a rather unique and highly distorted -type dihydride platinum(II) structure.
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- - Novel aluminium complexes with unique helical structures were created using large heteroscorpionate ligands, allowing for the isolation of new intermediates in their formation.
- - These helical aluminium complexes were tested for their ability to catalyze cyclic carbonate production under mild conditions, demonstrating effective performance.
- - The most effective catalyst, combining complex 16 and BuNBr, successfully produced a variety of monosubstituted and disubstituted cyclic carbonates from epoxides and carbon monoxide at room temperature.
Article Synopsis
- Nonisocyanate polyurethane materials were created by reacting bis(cyclic carbonates) with various diamines, using 1,4-butanediol bis(glycidyl ether carbonate) as the main starting material.
- The reactions yielded poly(hydroxyurethane) materials efficiently after 16 hours at 80 °C in MeCN, though L-lysine did not react due to its low reactivity; however, the use of strong bases like DBU or TBD allowed for successful reactions, albeit with some unwanted byproducts.
- Characterization of the resulting materials was conducted using various spectroscopic methods (NMR, IR, MALDI-ToF, GPC), and their thermal properties were analyzed, alongside experiments
The direct reaction of the highly sterically demanding acetamidinate-based NNN'-scorpionate protioligand Hphbpamd [Hphbpamd = ,'-di-p-tolylbis(3,5-di-tertbutylpyrazole-1-yl)acetamidine] with one equiv. of ZnMe proceeds in high yield to the mononuclear alkyl zinc complex [ZnMe(-phbpamd)] (). Alternatively, the treatment of the corresponding lithium precursor [Li(phbpamd)(THF)] with ZnCl yielded the halide complex [ZnCl(-phbptamd)] ().
View Article and Find Full Text PDFThe catalytic activity and high selectivity reported by bimetallic heteroscorpionate acetate zinc complexes in ring-opening copolymerization (ROCOP) reactions involving CO as substrate encouraged us to expand their use as catalysts for ROCOP of cyclohexene oxide (CHO) and cyclic anhydrides. Among the catalysts tested for the ROCOP of CHO and phthalic anhydride at different reaction conditions, the most active catalytic system was the combination of complex with bis(triphenylphosphine)iminium as cocatalyst in toluene at 80 °C. Once the optimal catalytic system was determined, the scope in terms of other cyclic anhydrides was broadened.
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- Zinc complexes haven't been used as catalysts for hydroalkoxylation of alkynyl alcohols until now, but scorpionate zinc complexes have shown promise.
- A specific zinc amide complex serves as an effective precatalyst, enabling a selective reaction that produces exocyclic enol ethers.
- Kinetic studies reveal that the reaction depends on the catalyst concentration and X-ray and NMR analyses helped identify an alkynyl zinc compound as a crucial intermediate, leading to a proposed catalytic cycle.
Article Synopsis
- Bio-derived cyclic carbonates, including those from terpenes and 10-undecenoic acid, were successfully synthesized using terminal epoxides and CO, achieving high yields.
- A catalyst system allowed for the efficient conversion of an epoxidized fatty acid n-pentyl ester into a cyclic carbonate under mild conditions, with variable cis/trans ratios based on the co-catalyst used.
- Two of the cyclic carbonates were utilized to create non-isocyanate poly(hydroxy)urethanes by reacting with 1,4-diaminobutane.
Article Synopsis
- - This study explores the rapid reaction of polar organometallic compounds with cyclic carbonates, using 2-methyltetrahydrofuran as a green solvent at room temperature and in the presence of air and moisture, which is typically not allowed for these reactive substances.
- - The right combination of reagents enables the easy creation of various products like tertiary alcohols, β-hydroxy esters, and symmetric ketones without needing a complicated setup.
- - An innovative one-pot/two-step method combines an aluminum-catalyzed reaction of carbon monoxide with propylene oxide and the fast addition of organolithium reagents, allowing the production of complex alcohols directly from CO without isolating any intermediate compounds.
Cisplatin is one of the most widely used chemotherapeutic agents in the treatment of different tumors but has high toxicity and side effects. Therefore, the synthesis of new chemotherapeutic agents is necessary, so that they are effective in the treatment of cancer while avoiding such toxicity. In this study, we have synthesized and characterized a palladium(II) complex, [PdCl(µ-PyTT)]Cl·4HO (PdPyTT), with 2-(2-pyridyl)imine-N-(2-thiazolin-2-yl)thiazolidine (PyTT) as a ligand; besides, its cytotoxicity and pro-apoptotic capacity was tested in human promyelocytic leukemia HL-60 cell line.
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- Researchers developed new bimetallic zinc acetate complexes using heteroscorpionate ligands for the polymerization processes involving cyclohexene oxide and carbon monoxide (CO).
- The synthesized zinc complexes were confirmed through spectroscopy and X-ray diffraction, leading to successful high yields of the compounds.
- The complexes were tested as catalysts, with one particular complex showing high activity for copolymerizing cyclohexene oxide and CO, and further studies led to effective terpolymerization with additional compounds to create polyester-polycarbonate materials.
Eluding apoptosis represents the hallmark of tumoral cell behavior. Cisplatin (CisPt) is a very common chemotherapeutic agent to treat cancer by reestablishing apoptotic mechanisms of cell death. However, certain patients acquire resistance to CisPt as well as suffer nephrotoxicity, neurotoxicity, nausea and vomiting.
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- - Recent studies have investigated the use of the tyrosine kinase inhibitor dasatinib (DAS) for breast cancer treatment, but its low solubility poses challenges for effective delivery and uptake of the drug.
- - Researchers developed biodegradable polyester nanoparticles (NPs) that successfully encapsulate DAS, showing improved drug release profiles and potential for safer clinical use compared to existing delivery methods.
- - The new DAS-loaded nanoparticles demonstrated enhanced therapeutic efficacy against breast cancer without altering the drug's mechanism of action, highlighting their promise as a drug delivery system for further evaluation.
Article Synopsis
- The text discusses the optimization of an organoaluminum catalytic system to enhance the copolymerization of epoxides and anhydrides.
- It analyzes different process variables, including catalysts, cocatalysts, solvents, and substrates, to determine their effects on the copolymerization.
- The findings include kinetic studies, a proposed catalytic mechanism, complete characterization of the produced copolymers, and the introduction of a new copolymer called poly(limonene succinate).
Article Synopsis
- Helical aluminium complexes were synthesized using scorpionate ligand precursors and trialkylaluminium derivatives, resulting in various structures, including [Al2X4(μ-nbptam)] and [Al3X7(μ-fbpam)] with different alkyl groups.
- Structural analysis was performed through spectroscopic methods, and X-ray crystallography confirmed the structure of one complex, [Al2Me4(μ-nbptam)].
- These complexes showed promising catalytic activity in converting carbon dioxide into cyclic carbonates, with the yield of polyether-polycarbonate being influenced by the choice of cocatalyst and their ratio to the catalyst.
Article Synopsis
- New bifunctional aluminum complexes were developed to investigate how different counterions influence the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO).
- Researchers created four new zwitterionic NNO ligands using a neutral ligand precursor and reacted them with aluminum derivatives, leading to the formation of various mono- and bimetallic complexes.
- Catalytic tests revealed that iodide complex 11 was the most effective for terminal epoxides, while bromide complex 9 excelled with internal epoxides, highlighting the significance of cocatalysts in their activity.