A single residue switch leading to hydroxylation has been identified in -kaurene synthases (KSs) from plant gibberellin hormone biosynthesis. In this work, we identified a putative equivalent in the bacterial BjKS from the gibberellin-producing . Notably, this serves as a key residue that can be varied in concert with a surrounding network to redirect product outcome, with a specificity of up to 94%, providing mechanistic insight into not only BjKS but also (di)terpene synthases more generally.

Fine-chemical manufacturing, with its dismal E-factors, has been known for decades as being one of the worst contributors to the well-being of the environment. Further, mining practices that pursue precious metals used in catalysis lead to considerable destruction of the environment. Further contributing to this is the necessity for high catalyst loads due to the limited mortality of organometallic complexes in solution. Bimolecular decomposition (BD), in particular, is a significant contributor to this problem. Assisting in the sustainability of chemical synthesis is flow chemistry, whose "just-in-time" nature produces chemicals as needed, eliminating vast stockpiles of chemicals associated with batch manufacturing. In this work, Pd-PEPPSI-IPent, a high-reactivity, high-selectivity Pd catalyst, has been mounted onto the surface of silica, of which the spacing has eliminated BD. This material has been loaded into packed beds and used in Negishi coupling and Buchwald-Hartwig amination, where the active catalyst has shown tremendous resiliency while producing valuable small-molecule products with deft selectivity and speed with residence time in the order of minutes under mild conditions (e.g., Negishi couplings conducted at room temperature).

A substrate-regulated divergent addition of -sulfonyl ketimines to bicyclo[1.1.0]butanes (BCBs) was developed using a photoinduced energy transfer strategy. The [2π+2σ] cycloaddition of BCBs with saccharin-derived cyclic ketimines yields benzosultam-fused aza-BCHs with good yields and excellent diastereoselectivity. In contrast, reactions of chain -sulfonyl ketimines with BCBs produce 1,3-fully substituted cyclobutanes via energy-transfer-induced N-S bond homolysis. The ease of large-scale synthesis and derivatizations of products highlight their application potentials.

The carbanion derived from chlorodiborylmethane can act as a soft nucleophile, while the halogen substituent can subsequently function as a leaving group. Taking advantage of this feature, we herein have developed an efficient synthesis of -diborylcyclopropyl ketones from a diverse range of enone substrates. We also demonstrated the synthetic utility of this protocol by leveraging the highly transformable nature of the cyclopropyl moiety and the C-B bonds.

We report a novel coupling strategy enabled by cyclic diphenylchloronium salt that facilitates reactions between sulfides and diverse nucleophiles, including oxygen- and nitrogen-based species. The methodology efficiently produces structurally varied valuable compounds, including carbamates, carboxylic esters, aryl ethers, and alkylated amines, under mild, operationally simple conditions. The protocol's synthetic utility was highlighted through modular preparation of five important drugs and five structural analogues, demonstrating significant potential for drug discovery applications.

An efficient and expeditious method to assemble -bridged polycycles bearing up to six contiguous stereocenters from a gold(I)-catalyzed [3 + 2] cycloaddition/unactivated C(sp)-H bond insertion cascade of -1,6-enynyl benzaldehydes at a low catalyst loading of 2 mol % is described.

Here, we report the use of iminosulfur oxydifluorides, derived from SOF and primary amines, for the generation of the unprecedented aza-analogues of fluorosulfury azide (FSON), namely, fluorosulfonimidoyl azide (R-N═SOFN). Unlike FSON, R-N═SOFN acts as a sulfamoyl nitrene precursor, undergoing imidation with sulfoxides and thioethers to from products featuring unique "-N = S(VI)F-N = S(VI)-" linkages without metal catalyst. The fluoride at the S(VI) center can be sequentially exchanged to generate diverse three-deminsional structures with tunable SuFEx reactivity. Mechanistic studies reveal that R-N = SOFN decomposes to the sulfamoyl nitrene intermediate, which is stabilized by the adjacent "-S(VI)=N-" nitrogen atom. This facilitates the formation of three-membered rings that react further with S(IV)/S(II). These novel transformations expand the scope of SOF-based SuFEx chemistry, demonstrating that R-N = SOFN enables dual reactivity through both nitrene-driven and tunable SuFEx-based linkages.

Herein, we report the development of a general ring expansion strategy that involves the formal self-dimerization of benzocyclobutenones (BCBs) through nickel catalysis. These formal self-dimerizations of BCBs are efficient and scalable and provide a facile and unique construction of diverse seven-membered ring ketones and 1-isochromen-1-ones with high structural diversity. Moreover, the solvent effects and CO atmosphere play a crucial role in promoting CO exclusion, which may address regioselectivity control toward the (4 + 4 - 1) product, while NaOAc as an additive under a N atmosphere promoted (4 + 2) product formation.

Modifying the core structure of porphyrin dyes significantly impacts their electronic properties. However, the structure-property relationships of azaacene-fused heteroporphyrins remain underexplored. This study presents the synthesis and electronic properties of novel azaacene-fused 21,23-dithiaporphyrins. These dyes exhibit markedly red-shifted optical properties, reaching the near-infrared (NIR) region upon protonation and emitting in the NIR region in the neutral state.

A simple visible-light-promoted iron-catalyzed aerobic oxidative C-C bond cleavage of vicinal diols was developed. This reaction avoids the use of noble metal catalysts or specialized oxidants, yielding aldehydes and ketones without overoxidation. The new method works under air and at room temperature and features mild conditions and simple operation. Notably, the protocol is applicable for complex natural products, achieving the bioinspired conversion of the natural abundant diterpene oridonin to the natural rare enmein-type diterpene.

We demonstrate that polysulfide anions are capable of catalyzing desulfonylation of sulfonamides having a series of aryl and alkyl substituents in the presence of potassium formate under irradiation with visible light. The developed protocol is operationally concise and cost-effective, representing a practical and sustainable synthetic tool for desulfonylation and expanding the chemical space in secondary amine synthesis.

Five new macrocyclic napyradiomycins with different types of scaffolds were isolated from marine-derived SJ-019. Compounds and are uniquely typified by a spirocyclic core, while , and also contain a unique macrolide structure not known in any other napyradiomycins. Compound is composed of a dearomatized napyradiomycin core and an intramolecular double-arch bridge system. Compound displays potent inhibition of , while C-type napyradiomycin shows notable anti-inflammatory effect.

Alkyl azetidines have been prepared by photochemical modifications of azetidine-2-carboxylic acids and . The reaction has been realized in milligram, gram, and even multigram quantities. The obtained azetidines are valuable building blocks for drug discovery.

Aurantiacin A (), a unique ascorbylated meroditerpenoid composed of an unusual 9--spiro-lactone-type -kaurane diterpenoid core, ascorbic acid (vitamin C), and syringic acid, and three new 9--spiro-lactone-type -kauranoids, aurantiacins B-D (-), were isolated from an untapped species, . Their structures were determined by spectroscopic data analysis, semisynthesis, floating chirality distance geometry calculations, and quantum chemical calculations. Aurantiacin A () was found to induce lysosomal biogenesis, and the potential mechanisms underlying this effect were preliminarily explored.

In the presence of catalytic amounts of PtCl and LiI, alkenylsilanes reacted with dimethyl acetals of aromatic aldehydes in acetonitrile to give allylic methyl ethers. This alkenylation reaction occurred not at the α-carbon bound to silicon but at the β-carbon of alkenylsilanes. Use of chlorotrimethylsilane as an additive was effective in promoting the alkenylation of certain acetals. The PtCl-catalyzed hydrosilylation of terminal alkynes with triethylsilane and subsequent alkenylation of acetals enabled easy and rapid synthesis of allylic ethers.

An efficient electrochemical bromocyclization of allenols has been realized for the synthesis of spirocyclic 2,5-dihydrofurans. The reaction used commercially available and nontoxic KBr as the brominating source in a simple setup under open-air conditions. Notably, optically active products can be obtained from optically active 2,3-allenols without any racemization, further enhancing the synthetic utility.

In the quest for developing catalysts with multiple active sites, we designed a series of methionine-based peptide catalysts prepared by classical peptide coupling. Given the widespread presence of aromatic chloro-substituents and their significant pharmacokinetic properties, the performance of these catalysts were evaluated for the late-stage chlorination of tyrosine residue on peptides up to octamer as well as aromatic drug molecules. The operationally simple reaction conditions, excellent catalyst loading up to 0.25 mol %, and gram-scale reactions are major highlights of this method.

1,2-Difunctionalization of alkynes is an attractive synthetic protocol, because it can achieve a high step economy and provide various complex organic molecules. This study demonstrates the visible-light-induced carbamoylarylation of terminal alkynes using -aryl oxamic acids as bifunctional reagents. The transformation involves the addition of carbamoyl radicals to alkenes, resulting in 1,4-aryl migration via C(aryl)-N bond cleavage to afford the corresponding arylacrylamides in moderate to good yields.

A new synthetic method for the synthesis of bicyclic scaffolds featuring a dihydropyran and tetrahydrofuran (THF) hybrid in the fashion of a fused structure with excellent -selectivity is realized via the reactions of enaminones and THF. In addition to displaying a dual role as both a cyclic fragment and a one-carbon synthon, the current method also shows a rarely known mode of two vicinal C-H bonds' functionalization in THF or analogous oxa-heterocycles.

Nearly 90% of poly(methyl methacrylate) (PMMA) is not recycled and instead ends up in landfills. Conventional pyrolysis of PMMA recovers impure methyl methacrylate (MMA) with low economic value. Here, we present a telescoped dual upcycling strategy that integrates PMMA depolymerization, Diels-Alder cycloaddition, and aromatization to convert AMS-doped PMMA and biomass-derived 2,5-dimethylfuran (DMF) into 1,2,4-trimethylbenzene (pseudocumene), a valuable chemical feedstock. BBr proved effective in promoting the challenging Diels-Alder reaction between MMA and DMF under high pressure of argon.

Herein, we report a visible light-induced synthesis of sulfenamides via the oxidative coupling of amines with thiols using O as an oxidant. The photoreaction was conducted under simple and mild conditions, without any photocatalysts, metals, or additives. Detailed mechanistic studies revealed that a sulfur radical is generated through a single-electron transfer from an in situ-generated sulfur anion to O under visible light irradiation. This radical intermediate couples to form disulfide, which subsequently undergoes aminolysis to produce sulfenamides.