Water-Dispersible, Magnetically Recyclable Heterogeneous Cobalt Catalyst for C-C and C-N Cross-Coupling Reactions in Aqueous Media.

A cobalt catalyst supported on an iron oxide core, denoted as γ-FeO@PEG@THMAM-Co, has been prepared and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray mapping, thermogravimetry differential thermogravimetry, vibrating sample magnetometry, and inductively coupled plasma. Polyhydroxy end groups in the shell make the catalyst particles dispersible in water, allowing Hiyama, Suzuki, and C-N cross-coupling reactions of aryl iodides and bromides. The catalyst could be recovered by magnetic decantation and reused for at least five successive runs with a negligent decrease in its activity or changes in its morphology.

Synergistic performance of a new bimetallic complex supported on magnetic nanoparticles for Sonogashira and C-N coupling reactions.

This paper describes the synthesis of a novel Cu-Ni bimetallic system comprising of magnetic nanoparticles, as the core, and 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole (4-ABPT), as a conjugated bridge, between nickel and copper species. With low Cu and Ni loading (0.06 mol% Ni, 0.

Correction: A novel, efficient and magnetically recyclable Cu-Ni bimetallic nanocomposite as a highly active bifunctional catalyst for Pd-free Sonogashira and C-N cross-coupling reactions: a combined theoretical and experimental study.

[This corrects the article DOI: 10.1039/D3RA01965A.].

A novel, efficient and magnetically recyclable Cu-Ni bimetallic alloy nanoparticle as a highly active bifunctional catalyst for Pd-free Sonogashira and C-N cross-coupling reactions: a combined theoretical and experimental study.

In this study, a FeO@SiO@Cyt-Ni/Cu nanocomposite as a novel heterogeneous bimetallic catalyst was synthesized which exhibits efficient performance for the Sonogashira and C-N cross-coupling reactions. The characterization of the catalyst was studied by FT-IR, PXRD, VSM, EDX, TEM, FE-SEM and TGA analyses. The geometry optimization and relative energies of the designed bimetallic complexes were theoretically determined using density functional theory (DFT) calculation at the B3LYP/6-31G**/LANL2DZ level.

Comparison of Robot-Assisted and Manual Cannula Insertion in Simulated Big-Bubble Deep Anterior Lamellar Keratoplasty.

This study aimed to compare the efficacy of robot-assisted and manual cannula insertion in simulated big-bubble deep anterior lamellar keratoplasty (DALK). Novice surgeons with no prior experience in performing DALK were trained to perform the procedure using manual or robot-assisted techniques. The results showed that both methods could generate an airtight tunnel in the porcine cornea, and result in successful generation of a deep stromal demarcation plane representing sufficient depth reached for big-bubble generation in most cases.

Copper adorned magnetic nanoparticles as a heterogeneous catalyst for Sonogashira coupling reaction in aqueous media.

A nanomagnetic hydrophilic heterogeneous copper catalyst, termed γ-FeO@PEG@PAMAM G-Cu, has been successfully prepared and characterized using FT-IR, XRD, FE-SEM, TEM, EDX, mapping, TGA/DTG, VSM and ICP analyses. The catalyst displayed excellent activity for the palladium-free Sonogashira cross coupling reaction of various aryl iodides and bromides with phenylacetylene derivatives in pure water. The presence of polyethylene glycol coupled with hydrophilic character of the Cu-catalyst adorned on γ-FeO MNPs provides the ready dispersion of the catalyst particles in water, leading to higher catalytic performance as well as facile catalyst recovery via simple magnetic decantation.

FeO@Sap/Cu(ii): an efficient magnetically recoverable green nanocatalyst for the preparation of acridine and quinazoline derivatives in aqueous media at room temperature.

Saponin, as a green and available phytochemical, was immobilized on the surface of magnetite nanoparticles then doped with Cu ions (FeO@Sap/Cu(ii)) and used as an efficient nanocatalyst for the synthesis of quinazoline and acridine derivatives, due to their high application and importance in various fields of science. Different spectroscopic and microscopic techniques were used for the catalyst characterization such as FT-IR, XRD, FE-SEM, EDX, TEM, TGA, VSM, BET, DLS, CV, and XPS analyses. All characterization data were correlated with each other so that the structure of the catalyst was accurately characterized.

Dendritic structured palladium complexes: magnetically retrievable, highly efficient heterogeneous nanocatalyst for Suzuki and Heck cross-coupling reactions.

The recyclable nanomagnetic Pd-complex PAMAM G-Pd@γ-FeO is reported for catalytic C-C cross-coupling reactions of challenging substrates. Mainly, a great variety of aryl chlorides can be used as substrates for Suzuki-Miyaura and Mizoroki-Heck reactions under mild reaction conditions (60-90 °C) and low catalyst loading (<1 mol% Pd) in aqueous media. The presence of numerous polar groups in the polymer matrix increases the solubility of the catalyst in water, thus facilitating its operation in aqueous environments.

A Tool for High-Resolution Volumetric Optical Coherence Tomography by Compounding Radial-and Linear Acquired B-Scans Using Registration.

Optical coherence tomography (OCT) is a medical imaging modality that is commonly used to diagnose retinal diseases. In recent years, linear and radial scanning patterns have been proposed to acquire three-dimensional OCT data. These patterns show differences in A-scan acquisition density across the generated volumes, and thus differ in their suitability for the diagnosis of retinal diseases.

Selective oxidation of alcohols and sulfides O using a Co(ii) salen complex catalyst immobilized on KCC-1: synthesis and kinetic study.

The aim of this study was to immobilize a Co(ii) salen complex on KCC-1 as a catalyst that can be recovered (Co(ii) salen complex@KCC-1). Field-emission transmission electron microscopy, FT-IR spectroscopy, thermogravimetric analysis, elemental analysis, atomic absorption spectroscopy, and XRD were used to confirm the structure and chemical nature of Co(ii) salen complex@KCC-1. The oxidation efficiency was obtained for an extensive range of sulfides and alcohols using this sustainable catalyst, alongside O as an oxygen source and isobutyraldehyde (IBA) as an oxygen acceptor, with superior selectivity and conversion for the relevant oxidation products (sulfoxides and ketones or aldehydes) under moderate conditions.

A Co-Cu bimetallic magnetic nanocatalyst with synergistic and bifunctional performance for the base-free Suzuki, Sonogashira, and C-N cross-coupling reactions in water.

A novel magnetically recyclable bimetallic catalyst was prepared by anchoring imidazolium moiety and PEG chains on Fe3O4 NPs and named as Fe3O4@PEG/Cu-Co. It was found to be a powerful catalyst for the Sonogashira, Suzuki, and C-N cross-coupling reactions in water as a green solvent without the need for any external base. Fe3O4@PEG/Cu-Co was well characterized with FT-IR, FE-SEM, TEM, VSM, EDX, ICP, UV-visible, CV, and XPS analyses.

Functionalized magnetic PAMAM dendrimer as an efficient nanocatalyst for a new synthetic strategy of xanthene pigments.

A green protocol has been developed for preparation of the wide variety of colored xanthene derivatives using a new efficient magnetic solid acid catalyst bearing polyamidoamine dendrimer moiety as a nanoscopic compound. Dendrimers, highly symmetric molecules around a core and 3D spherical morphology, show interesting traits based on their functionalized groups on the branched surface. They can be designed to provide water soluble structures or pseudo-active sites of biomolecules.

The CuFeO@SiO@ZrO/SO /Cu nanoparticles: an efficient magnetically recyclable multifunctional Lewis/Brønsted acid nanocatalyst for the ligand- and Pd-free Sonogashira cross-coupling reaction in water.

Herein, the synthesis and application of copper-incorporated sulfated zirconium oxide supported on CuFeO NPs (CuFeO@SiO@ZrO/SO /Cu NPs) as a novel Lewis/Brønsted acid nanocatalyst were studied for the Sonogashira C-C cross-coupling reaction. The fabricated CuFeO@SiO@ZrO/SO /Cu catalyst exhibited efficient activity for a large variety of aryl iodides/bromides and, most importantly, aryl chlorides in water and in the presence of NaOH as a base in short reaction times. The catalyst was fully characterized by FTIR, TG-DTG, VSM, XRD, EDX, FE-SEM and TEM analyses.

Fast 5DOF needle tracking in iOCT.

Purpose: Intraoperative optical coherence tomography (iOCT) is an increasingly available imaging technique for ophthalmic microsurgery that provides high-resolution cross-sectional information of the surgical scene. We propose to build on its desirable qualities and present a method for tracking the orientation and location of a surgical needle. Thereby, we enable the direct analysis of instrument-tissue interaction directly in OCT space without complex multimodal calibration that would be required with traditional instrument tracking methods.

Synthesis of dual-action parthenolide prodrugs as potent anticancer agents.

Cancer stem cells are responsible for the failure of a large number of cancer treatments and the re-emergence of cancer in patients. Parthenolide is a potent anticancer sesquiterpene lactone that is also able to kill cancer stem cells. The main problem with this compound is its poor solubility in water.

Magnetic nanoparticle supported hyperbranched polyglycerol catalysts for synthesis of 4-benzo[]pyran.

Abstract: A magnetic nanoparticle supported hyperbranched polyglycerol catalyst was prepared readily from inexpensive starting materials in aqueous medium that catalyzed the synthesis of 4-benzo[]pyran under solvent-free conditions at room temperature. X-ray diffraction, transmission electron microscopy, thermal gravimetric analysis, vibrating sample magnetometry, and selected-area electron diffraction were employed to characterize the properties of the synthesized catalyst. Its high catalytic activity and ease of recovery from the reaction mixture using an external magnet, and the possibility of reusing several times without significant loss of performance are additional eco-friendly attributes of this catalytic system.