Traditional Chinese medicine for post-viral olfactory dysfunction: A systematic review.

Background: Post-viral olfactory dysfunction (PVOD) is the common symptoms of long COVID, lacking of effective treatments. Traditional Chinese medicine (TCM) is claimed to be effective in treating olfactory dysfunction, but the evidence has not yet been critically appraised. We conducted a systematic review to evaluate the effectiveness and safety of TCM for PVOD. Methods: We searched eight databases to identified clinical controlled studies about TCM for PVOD. The Cochrane risk of bias tools and GRADE were used to evaluate the quality of evidence. Risk ratio (RR), mean differences (MD), and 95 % confidence interval (CI), were used for effect estimation and RevMan 5.4.1 was used for data analysis. Results: Six randomized controlled trials (RCTs) (545 participants), two non-randomized controlled trials (non-RCTs) (112 participants), and one retrospective cohort study (30 participants) were included. The overall quality of included studies was low. Acupuncture (n = 8) and acupoint injection (n = 3) were the mainly used TCM therapies. Five RCTs showed a better effect in TCM group. Four trials used acupuncture, and three trials used acupoint injection. The results of two non-RCTs and one cohort study were not statistically significant. Two trials reported mild to moderate adverse events (pain and brief syncope caused by acupuncture or acupoint injection). Conclusions: Limited evidence focus on acupuncture and acupoint injection for PVOD and suggests that acupuncture and acupoint injection may be effective in improving PVOD. More well-designed trials should focus on acupuncture to confirm the benefit. Protocol registration: The protocol of this review was registered at PROSPERO: CRD42022366776.

Chelation-assisted iridium-catalyzed hydroalkenylation and hydroarylation/cyclization with conjugated trienes.

Iridium-catalyzed hydroalkenylation of conjugated trienes by chelation-assisted alkenyl C-H activation of acrylamides has been demonstrated to produce 1,4,6-trienes atom efficiently with excellent regio- and E/Z selectivities. In contrast, the reaction of benzamides and 1,3,5-trienes proceeds by a tandem hydroarylation of the trienes and cyclization via intramolecular 1,2-addition, providing valuable trans-tetrahydroisoquinolinone derivatives. A broad range of aromatic and aliphatic 1,3,5-trienes bearing various functionalities were compatible to deliver target products with high yields and E/Z selectivity. The successful gram-scale preparation and selective hydrogenation to give the alkylation product further demonstrates the practicability of this protocol to potential applications.

Functionality-Directed Regio- and Enantio-Selective Olefinic C-H Functionalization of Aryl Alkenes.

Aryl alkenes represents one of the most widely occurring structural motif in countless drugs and natural products, and direct C-H functionalization of aryl alkenes provides atom- step efficient access toward valuable analogues. Among them, group-directed selective olefinic α- and ß-C-H functionalization, bearing a directing group on the aromatic ring, has attracted remarkable attentions, including alkynylation, alkenylation, amino-carbonylation, cyanation, domino cyclization and so on. These transformations proceed by endo- and exo-C-H cyclometallation and provide aryl alkene derivatives in excellent site- stereo-selectivity. Enantio-selective α- and ß- olefinic C-H functionalization were also covered to synthesis axially chiral styrenes.

Lignin-derived new hydrogen donors for photoinitiating systems in dental materials.

OBJECTIVES: The aim of this study is to develop amine free photo-initiating system (PIs) for the photopolymerization of dental methacrylate resins, using seven new hydrogen donors HDA-HDG derived from ß-O-4 lignin model. METHODS: Seven experimental CQ/HD PIs were formulated with Bis-GMA/TEGDMA (70 w%/30 w%). CQ/EDB system was chosen as the comparison group. FTIR-ATR was used to monitor the polymerization kinetics and double bond conversion. Bleaching property and color stability were evaluated using a spectrophotometer. Molecular orbitals calculations were used to demonstrate C-H bond dissociation energies of the novel HDs. Depth of cure of the HD based systems were compared to the EDB based one. Cytotoxicity was also studied by CCK8 assay using tissue of mouse fibroblasts (L929 cells). RESULTS: Compared to CQ/EDB system, the new CQ/HD systems show comparable or better photopolymerization performances (1 mm-thick samples). Comparable or even better bleaching properties were also obtained with the new amine-free systems. Comparing to EDB, all HDs exhibited significantly lower C-H bond dissociation energies by molecular orbitals calculations. Groups with new HD showed higher depth of cure. OD and RGR values were similar to that of the CQ/EDB group, ensuring the feasibility of the new HDs in dental materials. CLINICAL SIGNIFICANCE: The new CQ/HD PI systems could be potentially useful in dental materials, presenting improvements in restorations' esthetic and biocompatibility.

Synthesis of 3-Oxo Quinolines by Cyclization Using Lignin Models and 2-Aminobenzyl Alcohols.

Phenoxy acetophenones were usually employed as ß-O-4' lignin models for chemical conversion. Herein, an iridium-catalyzed dehydrogenative annulation between 2-aminobenzylalcohols and phenoxy acetophenones was demonstrated to prepare valuable 3-oxo quinoline derivatives, which are hard to prepare using previous methods. This operationally simple reaction tolerated a wide scope of substrates and enabled successful gram-scale preparation.

Ruthenium-catalyzed C-H amination of aroylsilanes.

Acylsilane represents a valuable synthon in synthetic chemistry. We report on ruthenium(ii)-catalyzed ortho-C-H amination of aroylsilanes to provide facile access to synthetically useful imidobenzoylsilanes and tosyl-amidobenzoylsilanes. The protocols, with broad substrate scope and excellent functional group tolerance, are enabled with the weak chelation-assistance of acylsilane via C-H cyclometallation.