Intermolecular Regioselective Alkylarylation of Vinylarenes via Photoredox/Nickel Dual Catalysis.

A novel photoredox/nickel dual catalytic intermolecular alkylarylation of vinylarenes with tertiary and secondary alkyltrifluoroborates and aryl bromides is described, which affords 1,1-diarylalkane frameworks that are found in various natural products as well as functionalized molecules in good to excellent yield and regioselectivity through a radical relay process. Notably, this redox-neutral reaction could proceed efficiently with good tolerance of various substrates, including a great diversity of commercially available (hetero)aryl bromides, alkyltrifluoroborates, and vinylarenes.

Single-staged revascularization and reconstruction after crush injury of the wrist and distal forearm: A protocolized approach.

BACKGROUND: Amputation of the wrist or distal forearm after high-energy trauma due to a crushing mechanism is associated with complex tissue defects, making repair, and reconstruction challenging. Given the difficulty of this type of salvage, patients unfortunately experience a high revision amputation rate. However, a higher quality of life has been reported in patients with successful reconstructions. Herein, we described a protocolized approach for revascularization and reconstruction for functional hand salvage after traumatic amputation from a crushing mechanism using an anterolateral thigh flap (ALT). METHODS: A retrospective review was performed between October 2016 and October 2023 for all patients who underwent single-stage emergent debridement, revascularization, and soft tissue coverage using the ALT after amputation at the level of the wrist or distal forearm secondary to high-energy crush injury. Charts were reviewed for the preoperative Mangled Extremity Salvage Score, intraoperative details including what structures were injured and the reconstructive method performed, and postoperative data such as follow-up duration, outcomes, and complications. RESULTS: Eleven patients met the inclusion criteria with an average age of 35.5 (21-49) years old. The average size of the skin soft tissue defects was 17.3 × 8 cm (range, length: 13-25 cm, width: 6-13 cm), and all cases had associated injury to the underlying bone, nerves, and blood vessels. The average size of the ALT flap used for reconstruction was 19.2 × 9.8 cm (range, length: 14-27 cm, width: 7-15 cm). All patients had survival of the replanted limb. One patient experienced partial flap necrosis that required secondary debridement and skin graft. Nine patients healed without requiring any additional debridement procedures. Patient follow-up averaged 24.6 (12-38) months. All patients achieved satisfactory functional recovery with Grade II to III of Chen's criteria. CONCLUSIONS: For patients with traumatic crush amputation to the wrist with surrounding soft tissue injury, thorough debridement, revascularization, and reconstruction of amputated limbs can be performed in a single stage using the ALT. A protocolized approach from two institutions is presented, demonstrating improved survival and reduced complications of the traumatized limb with improved long-term patient outcomes.

General Method for Selective Three-Component Carboacylation of Alkenes via Visible-Light Dual Photoredox/Nickel Catalysis.

A photoredox/nickel dual catalytic protocol for the regioselective three-component carboacylation of alkenes with tertiary and secondary alkyltrifluoroborates as well as acyl chlorides is described. This redox-neutral protocol can be applied to the rapid synthesis of ketones with high diversity and complexity via a radical relay process. Many functional groups, allowing for various commercially available acyl chlorides, alkyltrifluoroborates, and alkenes, are tolerated under these mild conditions.

A new synthesis of d-lyxose from d-arabinose.

A new synthesis of rare d-lyxose from easily available d-arabinose is disclosed. The route includes 7 steps with a total 40% yield. Inversion of configuration at C3 promoted by DAST reagent is utilized on trans-2,3-di-hydroxy pentofuranose to provide cis-2,3-di-hydroxy pentofuranose, which is hardly synthesized using normal method.

[Polydatin ameliorates myocardial fibrosis in rats by up-regulating SIRT3 and SDF-1].

Objective To investigate the effects and the possible mechanisms of polydatin on the myocardial fibrosis and cytokines of myocardium induced by adriamycin. Methods Twenty male SD rats was divided into four groups, 5 rats in every group. Control group (only fed with conventional diet), adriamycin group (treated with intraperitoneal injection of 2.5 mg/kg adriamycin for twice a week), polydatin treatment group (treated with intraperitoneal injection of 50 mg/kg polydatin for once a day) and nicotinamide treatment group (treated with intraperitoneal injection of 500 mg/kg SIRT3 inhibitor nicotinamide for twice a week). The effects of polydatin on adriamycin induced myocardial fibrosis and collagen expression in myocardium were evaluated by immunohistochemistry. The content of hydroxyproline (HYP) in myocardium was detected by enzyme labeling method. Spectrofluorometry was used to determine the level of superoxide dismutase (SOD) activity, glutathione (GSH) and malonaldehyde (MDA) level. ELISA was used to detect the content of tumor necrosis factor α(TNF-α), interleukin 1(IL-1)and IL-10. The levels of SIRT1, SIRT3, transforming growth factor-ß (TGF-ß) and stromal cell-derived factor-1(SDF-1) were examined by real-time quantitative PCR and Western blotting.Results Treatment with adriamycin promoted the myocardial fibrosis, reduced the level of IL-10, increased the level of TNF-α, IL-1 in myocardial tissue. The mRNA and protein levels of SIRT3 and SDF-1 was inhibited by adriamycin, whereas the expression of TGF-ß was promoted. The results showed that polydatin inhibited the fibrosis of myocardium induced by adriamycin, decreased the level of HYP, collagen III and MDA , whereas the level of SOD and GSH was increased. Treatment with nicotinamide attenuated the inhibitory effects of polydatin on the fibrosis of myocardium, inhibited the expression of SIRT3 and SDF-1, promoted the expression of TGF-ß. Conclusion Polydatin upregulates the expression of SIRT3 to increase the ability of anti-fibrosis and reduce the level of oxidative stress induced by adriamycin, inhibits the relase of cytokines.

Cp*Rh(iii) catalyzed ortho-halogenation of N-nitrosoanilines by solvent-controlled regioselective C-H functionalization.

We present a novel, efficient, and regioselective method for the rhodium-catalyzed direct C-H ortho-halogenation of anilines that involves a removable N-nitroso directing group. This method featured mild reaction conditions, wide substrate scope, good functional group tolerance and satisfactory yields. To maintain the high ortho-regioselectivity and conversion, increasing the steric hindrance of the solvent was critical. Preliminary mechanistic studies suggest that C-H activation may be involved in the rate-determining step.

Access to 2-substituted-2H-indazoles via a copper-catalyzed regioselective cross-coupling reaction.

A CuCl catalyzed C-N cross-coupling reaction using commercially available 1H-indazoles with diaryliodonium salts is described. The methodology features ample structural versatility, affording 2-substituted-2H-indazole in good yields and complete N(2)-regiocontrol. Furthermore, the utility of the reaction was demonstrated in the synthesis of a known estrogen receptor ß agonist. Mechanistic studies using density functional theory calculations suggested that the complete regioselectivity can be attributed to the only weak base TfO- in our system which could not deprotonate indazoles, and the catalyst oxidation process would be the rate-determining step.

Antibacterial effects of cinnamon (Cinnamomum zeylanicum) bark essential oil on Porphyromonas gingivalis.

The objective of this study was to investigate the antibacterial effects of cinnamon (Cinnamomum zeylanicum) bark essential oil (CBEO) and its principal constituent cinnamaldehyde against Porphyromonas gingivalis and to elucidate the antibacterial mechanism. GC-MS analysis showed that cinnamaldehyde was the major constituent in CBEO (57.97%). The minimum inhibition concentrations (MICs) of CBEO and cinnamaldehyde were 6.25 µg/mL and 2.5 µM for P. gingivalis, respectively. Nucleic acid and protein leakage was observed with increasing concentrations of CBEO and cinnamaldehyde. Additionally, propidium iodide uptake assays revealed CBEO and cinnamaldehyde at 1 × MIC impaired P. gingivalis membrane integrity by enhancing cell permeability. Morphological changes in P. gingivalis cells were observed by scanning electron microscopy, which indicated cell membrane destruction. To further determine the anti-biofilm effect, relative biofilm formation and established biofilms were examined, which demonstrated that both CBEO and cinnamaldehyde at sub-MIC levels inhibited P. gingivalis biofilm formation by 74.5% and 67.3% separately, but only CBEO slightly decreased established biofilms by 33.5% at 4 × MIC. These results suggest the potential of CBEO as a natural antimicrobial agent against periodontal disease. Furthermore, cinnamaldehyde was confirmed to be the antibacterial substance of CBEO with inhibitory action against P. gingivalis.

Rhodium(III)-Catalyzed Directed C-H Amidation of N-Nitrosoanilines and Subsequent Formation of 1,2-Disubstituted Benzimidazoles.

An efficient rhodium-catalyzed direct C-H amidation of N-nitrosoanilines with 1,4,2-dioxazol-5-ones as amidating agents has been developed. This method featured mild reaction conditions, a wide substrate scope and satisfactory yields. Besides, the amidated products could be readily converted to pharmaceutically valuable 1,2-disubstituted benzimidazoles via an HCl-mediated deprotection/cyclization process in one pot.

Improved Synthesis of 1-O-Acyl-ß-d-Glucopyranose Tetraacetates.

An improved synthesis of 1-O-acyl glucosyl esters that avoids the use of expensive Ag reagents as well as the hydrolysis of unstable glucosyl bromides is reported. Notably, ß-configuration products were obtained exclusively in good yields.

Rhodium-Catalyzed Regioselective C7-Olefination of Indazoles Using an N-Amide Directing Group.

A rhodium-catalyzed regioselective C-H olefination of indazole is described. This protocol relies on the use of an efficient and removable N,N-diisopropylcarbamoyl directing group, which offers facile access to C7-olefinated indazoles with high regioselectivity, ample substrate scope and broad functional group tolerance.

Asymmetric total syntheses of marine cyclic depsipeptide halipeptins A-D.

Halipeptins A-D (1 a-d) are a family of natural cyclic depsipeptides isolated from marine sponges. Total syntheses of these four compounds are detailed in this report. The key elements in this synthesis include the elaboration of the polysubstituted decanoic acid parts by two asymmetric aldol reactions, assembly of the N-methyl-delta-hydroxyisoleucine residue by using either aza-Claisen rearrangement or methylation of aspartates as the key steps, and macrocyclization at the polysubstituted decanoic acid alanine site.

CuI/N,N-dimethylglycine-catalyzed coupling of vinyl halides with amides or carbamates.

The CuI-catalyzed coupling reaction of vinyl halides with amides or carbamates proceeds well at room temperature to 80 degrees C in dioxane to give enamides using N,N-dimethylglycine as the promoter and Cs(2)CO(3) as the base. The geometry of the C-C double bond is retained during the reaction course. [reaction: see text]

Polyaniline-uricase biosensor prepared with template process.

Polyaniline (PANI) uricase biosensor prepared with template process is reported first in this paper. The fabrication process is as follows. Firstly, a PANI-uricase electrode is obtained using one-step process. Secondly, the electrode is hydrolyzed in 6.0 mol/dm(3) hydrochloric acid solution to remove the uricase that may be affected by aniline monomer from PANI film. Finally, active uricase is immobilized into the PANI film based on the principle of the doping and undoping of the conducting polymer and a PANI-uricase biosensor is obtained. Some factors that affect response current are studied, such as temperature, pH, potential and substrate concentration. The determination of biosensors indicates that the response current of the biosensor prepared by template process decreases only by about 18% for 60 days, but that prepared by two-step process decreases by approximately 39% for 40 h. The uricase in PANI-uricase biosensor prepared by template process mainly interacts with the nitrogen linked to the quinoid ring. The biosensor is characterized with FTIR, UV-Vis and SEM for the first time.