Caseymcallister2023
Reported here for the first time is the Ir-catalyzed γ-selective hydroboration of γ-substituted allylic amides under mild reaction conditions. A variety of functional groups could be compatible with reaction conditions, affording γ-branched amides in good yields with ≤97% γ-selectivity. We have also demonstrated that the obtained borylated products could be used in a series of C-O, C-F, C-Br, and C-C bond-forming reactions.A Brønsted base and Lewis acid cooperatively catalyzed 1,3-dipolar cycloaddition is reported through chiral dinuclear zinc catalysts. An asymmetric exo'-selective [3 + 2] cycloaddition of CF3-containing N-unprotected isatin-derived azomethine ylides is realized. In the presence of 10 mol % of catalyst, azomethine ylides react efficiently with methyleneindolinones, giving a series of trifluoromethyl-substituted 2,3-pyrrolidinyl dispirooxindoles with highly enantio- (up to 99% ee) and exo'-selectivity (>201 dr). Up to four contiguous stereogenic centers, including two adjacent spiro quaternary stereocenters, are constructed in one step.In the past few decades, organic-inorganic hybrid metal halides acting as single-component white light emission diodes (LEDs) have attracted extensive attentions, but most of the studies concentrate on the low-dimensional lead perovskites. Here, by using the nontoxic silver as optically active metal center, a series of hybrid silver halides based on one-dimensional structures were constructed and realized broadband white light emission. Compounds [H2DABCO][Ag2X4(DABCO)] (X = Br (1), I (2)) feature one-dimensional [Ag2X4(DABCO)]2- structures charged balanced by [H2DABCO]2+ cations. Compound 1 exhibits an efficient broadband white-light emission with photoluminescence quantum efficiency (PLQE) of about 2.1% and excellent photochemical stability, while compound 2 gives a broadband yellow-white emission centered at 556 nm. [HDABCO]3Ag5Cl8 (3) gives a strong broadband yellow emission (585 nm) with high PLQE of 6.7%, which can be easily fabricated as a white light emitting device. Sovilnesib clinical trial Based on the temperature-dependent, particle-size-dependent, and time-resolved PL measurements as well as other detailed studies, the broadband white-light emissions are ascribed to the synergetic effects of the organic and inorganic components. Our work provides a unique structural assembly method to explore lead-free single-component white-light illuminants from molecular level.The peculiar surfaces of halloysite nanotubes and their biocompatibility are attracting the interest of researchers based on the wide range of attainable applications. The large aspect ratio of this nanotubular material ensures promising properties as a reinforcing agent in polymeric matrixes, such as cellulose and its derivatives, that entail strengthening due to, for instance, aging-induced degradation. The halloysite cavity has a suitable size for hosting a large variety of active species such as deacidifying (calcium hydroxide) and flame retardant agents (fluorinated surfactants) for a controlled and sustained release relevant to the conservation of cultural heritage. Additionally, anionic surfactants can be selectively adsorbed at the inner surface generating inorganic micelles able to solubilize hydrophobic species in a controlled cleaning protocol. We briefly discuss how the natural halloysite nanotubes can be supportive in various conservation processes of cultural heritage and present an outlook for future perspectives.The initial phases of neuronal differentiation are key to neuronal function. A particularly informative model to study these initial phases are retinoic acid-stimulated SH-SY5Y cells. Although these progressions are associated with redox-sensitive processes, it is largely undefined how the cellular proteome underpins redox dynamics and the management of reactive oxygen species. Here, we map the global cysteine-based redox landscape of SH-SY5Y cells using quantitative redox proteomics. We find evidence that redox alterations occurred early in differentiation and affect the expression of neuronal marker proteins and the extension of neurites. The spatiotemporal analysis of reactive oxygen species suggests a NOX2-dependent peak in cytoplasmic superoxide anions/hydrogen peroxide generation 2 h after retinoic acid stimulation. At the same time point, 241 out of 275 proteins with an altered cysteine redox state are reversibly oxidized in response to retinoic acid. Our analyses pinpoint redox alterations of proteins involved in the retinoic acid homeostasis and cytoskeletal dynamics.This article describes the synthesis of nanoporous silver submicrocubes (Np-Ag) capped with poly(allylamine hydrochloride) PAH/poly(styrenesulfonate) PSS bilayers (Np-Ag(PAH/PSS)n, 1 ≤ n ≤ 4) via layer-by-layer (LBL) assembly for the electrochemical glucose sensing. The consecutive LBL encapsulation of Np-Ag (average size ≈530 nm) with positively charged PAH and negatively charged PSS layers was monitored by using ζ-potential analyses, which showed that the sign of the ζ-potential became positive (+10 mV) or negative (-22 mV) depending on the charge of the encapsulating species. The thickness of two PAH/PSS bilayers on the Np-Ag was estimated to be ∼4 nm (consistent with a literature value of ∼1 nm per PAH or PSS layer) on the basis of a high-resolution transmission electron microscopy image of the Np-Ag(PAH/PSS)2. Moreover, the high quality of the polyelectrolyte capping on Np-Ag was evidenced by the elemental mapping analysis of particles (obtained by using high-angle annular dark-field scanning transmission electron microscopy), which showed a uniform spatial distribution of C, N, and S (derived from PAH and PSS layers). Among the four different Np-Ag(PAH/PSS)n (1 ≤ n ≤ 4) electrodes, Np-Ag(PAH/PSS)2 exhibited the highest electrocatalytic activity toward glucose because of the optimal thickness and density of its polyelectrolyte films (fabricated onto Np-Ag). The (Np-Ag(PAH/PSS)2 electrode demonstrated a detection limit of 20 μM, a sensitivity limit of 472.15 μA mM-1 cm-2, and a wide range of detection for glucose at concentrations as high as 23.3 mM along with good selectivity toward glucose. The findings of this study are expected to contribute to improvements in the fabrication and stability of various particle-type catalysts on an electrode surface and to efforts to optimize the device performance using the LBL encapsulation technique.