Coating photoanodes with transition‐metal hydroxides (TMH) is a promising approach for improving photoelectrochemical (PEC) water oxidation. However, the present system still suffers from high charge recombination and sluggish surface reactions. Herein, effective charge separation is achieved at the same time as boosting the surface catalytic reaction for PEC water splitting through decoration of plasmon metal (Ag) in a semiconductor/TMH coupling system. The kinetic behavior at the semiconductor/TMH and TMH/electrolyte interfaces is systematically evaluated by employing intensity modulated photocurrent spectroscopy, scanning photoelectrochemical microscopy, and oxygen evolution reaction model. It is found that both charge transfer and surface catalysis dynamics are enhanced through local surface plasmon resonance of Ag nanoparticles. The as‐prepared BiVO4/Co(OH)x‐Ag exhibits remarkable activity (≈4.64 times) in PEC water splitting in comparison with pure BiVO4. Notably, this smart approach can be also applied to other TMH (Ni(OH)2), reflecting its universality. This work provides a guiding design method for solar energy conversion with the semiconductor‐TMH system.

Proteolysis targeting chimeras (PROTACs) have emerged as useful chemical probes and potential therapeutics by taking advantage of the ubiquitin−proteasome system to degrade intracellular disease-associated proteins. PROTACs are heterobifunctional molecules composed of a target protein ligand, E3 ubiquitin ligase ligand, and a linker between them. The generation of efficient PROTACs requires screening of many parameters, especially the lengths and types of the linkers. We report our proof-ofconcept study using a two-stage strategy to facilitate the development of PROTACs against the estrogen receptor (ER). In stage one, a library of close to 100 PROTACs was synthesized by simply mixing a library of ERα ligands containing a hydrazide functional group at different positions with a preassembled library of E3 ligase ligands bearing different types and lengths of linkers with a terminal aldehyde group in a 1:1 ratio. Cell-based screening occurred without further purification, because the formation of the acylhydrazone linkage is highly efficient and produces water as the only byproduct. Compound A3 was the most potent ER degrader in two ER+ cell lines (DC 50 = ∼ 10 nM, D max = ≥ 95%). Stage two involved transformation to a more stable amide linker to generate a more drug-like molecule. The new compound, AM-A3, showed comparable biological activity (DC 50 = 1.1 nM, D max = 98%) and induced potent antiproliferation (IC 50 = 13.2 nM, I max = 69%) in MCF-7. This proof-of -concept study demonstrates that the two-stage strategy can significantly facilitate the development of PROTACs against ER without the tedious process of making large numbers of PROTACs one by one. It has the potential to be expanded to many other targets.

The control of the stereochemistry at the anomeric position is still one of the major challenges of synthetic carbohydrate chemistry. We have developed a new strategy consisting of a chiral catalyst-directed acylation followed by a palladium-catalyzed glycosidation to achieve high α- and β-stereoselectivity on the anomeric position. The former process involves a dynamic kinetic diastereoselective acylation of lactols derived from Achmatowicz rearrangement, while the latter is a stereospecific palladium-catalyzed allylic alkylation.

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Figure 3. a) Plausible mechanism. b) Scheme of the TCPP-Fe/Fe ultra-thin metallized film catalyzed oxidative dehydrogenation of aromatic hydrazides reactions. c) Catalytic efficiency in the reaction over the five cycles. 7 of 7) www.advancedsciencenews.com (

We have developed the first intermolecular hetero-[5+ +2] cycloaddition reaction between oxidopyrylium ylides and cyclic imines with excellent control of regio-and stereoselectivity.S urprisingly,d ivergent stereochemistry was observed depending on the substitution pattern of the oxidopyrylium ylide.T his new reaction provides quicka ccess to highly substituted nitrogen-containing seven-membered rings-azepanes.N otably,abroad range of oxidopyrylium ylides and cyclic imines participate in this novel hetero-[5+ +2] cycloaddition reaction and the cycloadducts can be readily transformed into the core skeletons of bioactive natural products.D FT calculations revealed that the cycloaddition proceeds through as tepwise pathway and the imine nitrogen atom serves as the nucleophile to initiate the cycloaddition. Cycloadditionisoneofthemostefficientandpowerfulwaysto build molecular complexity.A lthough various cycloaddition reactions have been developed for the synthesis of complex four-, five-, and six-membered rings with excellent control of regio-and stereoselectivity,far fewer methods are available for the formation of highly substituted sevenmembered rings. [1][2][3] Since the first report by Hendrickson in 1980, [4] oxidopyrylium ylide based [5+ +2] cycloaddition [5] has emerged as apowerful transformation for the construction of seven-membered carbocycles. [2,6,7] Most previous studies have focused on intramolecular oxidopyrylium-alkene cycloaddition with the alkene 2p components tethered to C2 or C6 position, that is,type Ioxidopyrylium-alkene cycloaddition. [6] In 2015, Lisg roup demonstrated that type II [5+ +2] cycloaddition is feasible by tethering the alkene to the C5 position of an oxidopyrylium ylide,w hich leads to various highly functionalized bridged seven-membered carbocycles. [8] This reaction was then applied to the construction of the carbon core of eurifoloid A [9] and the total synthesis of isocyclocitrinol. [10] In contrast, the intermolecular version of the oxidopyrylium-based [5+ +2] cycloaddition is much less studied and the substituent effect of the oxidopyrylium ylide on endo/ exo selectivity remained underexplored. [5][6][7] Furthermore, despite the importance of the oxidopyrylium-based [5+ +2] cycloadditions,t he 2p partners have been to date limited to alkenes,d ienamine,t rienamine,a nd alkynes.T ot he best of our knowledge,n oh etero-[5+ +2] cycloaddition of oxidopyrylium ylides with imines has ever been reported.As part of our continuing efforts in developing novel [5+ +2] cycloaddition reactions, [11] we became interested in the synthesis of highly substituted nitrogen-containing sevenmembered heterocycles-azepanes-through hetero-[5+ +2] cycloadditions as shown in Scheme 1A.Azepanes are present in numerous natural products such as rubenine, [12] cadambine, [13] and banistenoside [14] (Scheme 1B), which possess complex penta-and even hexa-substituted azepane cores.The feasibility,regio-, and stereoselectivty of the proposed hetero-[5+ +2] cycloaddition are entirely unknown. We herein des...

A general method has been developed for the formation of glycosyl chlorides and bromides from picolinic esters under mild and neutral conditions. Benchtop stable picolinic esters are activated by a copper­(II) halide species to afford the corresponding products in high yields with a traceless leaving group. Rare β glycosyl chlorides are accessible via this route through neighboring group participation. Additionally, glycosyl chlorides with labile protecting groups previously not easily accessible can be prepared.

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