Anion cascade reactions Ⅲ:Synthesis of 3-isoquinuclidone bridged polycyclic lactams

Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridged polycyclic lactams from readily available malonamides and 1,4‑dien-3-ones.Various highly substituted bridged polycyclic lactams were synthesized in good to excellent yields by tandem nucleophilic sequences in the presence of t BuOK in commercially available EtOH solvent at 60℃.Notably,the simple reactions can be run on a gram scale.Mechanistically,bis-Michael addition reaction and hemiaminalization reactions are involved in the tandem transformation.

Metal-free nucleophilic 7,8-dearomatization of quinolines:Spiroannulation of aminoquinoline protected amino acids

Atom-and step-economy in IBX assisted diversity-oriented synthesis is achieved with a versatile AQ auxiliary α-amino acid analogs offering rapid access to polycyclic spiro-quinolines featuring a quaternary stereocenter in 20%–91% yields under mild conditions via 7,8-dearomatization of quinolines. Free of a preinstalled activation group is highlight of this intramolecular oxidation spiroannulation tandem reaction. This type of N-heterospirocycles, traditionally difficult to access, may open the door to a potentially interest scaffold for synthetic and medicinal chemistry.

Regulated adsorption-diffusion and enhanced charge transfer in expanded graphite cohered with N,B bridge-doping carbon patches to boost K-ion storage

The great challenges are remained in constructing graphite-based anode with well built-in structures to accelerate kinetics and enhance stability in the advanced K-ion batteries(KIBs).Here,we firstly report the design of expanded graphite cohered by N,B bridge-doping carbon patches(NBEG)for efficient K-ion adsorption/diffusion and long-term durability.It is the B co-doping that plays a crucial role in maximizing doping-site utilization of N atoms,balancing the adsorption-diffusion kinetics,and promoting the charge transfer between NBEG and K ions.Especially,the robust lamellar structure,suitable interlayer distance,and rich active sites of the designed NBEG favor the rapid ion/electron transfer pathways and high K-ion storage capacity.Consequently,even at a low N,B doping concentration(4.36 at%,2.07 at%),NBEG anode shows prominent electrochemical performance for KIBs,surpassing most of the advanced carbon-based anodes.Kinetic studies,density functional theory simulations,and in-situ Raman spectroscopy are further performed to reveal the K-ion storage mechanism and confirm the critical actions of co-doping B.This work offers the new methods for graphite-electrode design and the deeper insights into their energy storage mechanisms in KIBs.

Visible-light-induced direct 3-ethoxycarbonyl- methylation of 2-aryl-2H-indazoles in water

A visible-light-driven rhodamine B-catalyzed transition-metal-free 3-ethoxycarbonylmethylation of 2-aryl-2H-indazoles and imidazo[1,2-a]pyridines(40 examples)using commercially availableα-bromoesters was realized in water.This protocol features sustainability,operational simplicity,mild reaction conditions,and remarkable substrate scope.Importantly,α-bromoamides are also appropriate substrates for affording 3-carbamylmethylation products.It could be used for the synthesis of the drug zolpidem and the late-stage modification of natural products.

Multi-Functional Supramolecular-Polymeric Hybrid Hydrogel for Promoting Cutaneous Wound Repair

Supramolecular-polymeric hybrid hydrogels combining advantages of the assembled supramolecular networks and polymeric networks have attracted considerable attention recently.However,they are rarely used as multi-functional wound dressing materials.In this work,we report a supramolecular-polymeric hybrid hydrogel consisting of a co-assembled DBS-COOH/Naproxen network(DBS/NAP)and a polymeric gelatin(G)/quaternary ammonium group(Q)and phenylboronic acid groups(PBA)-grafted chitosan(QCS-PBA)network(G/QCS)for accelerating skin wound healing.The polymeric networks could obviously enhance the mechanical properties of the drug-derived supramolecular networks.Q groups endowed the hydrogel with enhanced antibacterial properties.Borate ester crosslinking between PBA groups and diol groups in DBS-COOH could effectively scavenge reactive radicals.The hybrid hydrogel exhibited tunable mechanical and adhesive properties due to the temperature-responsive gelatin networks.NAP could gradually release from hybrid hydrogel networks thus continuously relieving inflammation.Finally,the biocompatible,adhesive,antibacterial and antioxidant hybrid G/QCS-DBS/NAP gel could promote the in vivo healing stages in a full-thickness wounds with increased collagen deposition,upregulated CD31 expression and down-regulated TNF-αexpression.Overall,this multi-functional supramolecular-polymeric hybrid hydrogel exhibited great potential for treating skin defects as promising wound dressing materials.