Alkylthianthrenium salts can be shaken up in a ball mill on a decagram scale

Abstract. Fused cyclopropanes are prominent motifs in bioactive molecules, yet their incorporation into densely functionalized frameworks remains a signifi

Cyclopropanes are organic chemistry's smallest rings. Three carbon atoms are joined in a triangle, creating a compact and unusually strained structure. Despite—or partly because of—this unusual geomet...

Cyclopropanes are organic chemistry's smallest rings. Three carbon atoms are joined in a triangle, creating a compact and unusually strained structure.

Nature Catalysis, Published online: 09 July 2026; doi:10.1038/s41929-026-01566-zEnergy transfer (EnT) catalysed dearomative cycloadditions of bicyclic azaarenes are largely limited to [4+2] pathways, with higher-order cycloadditions being difficult to achieve. Now, the authors circumvent this limitation by establishing a higher-order cycloaddition followed by cascades. This triple EnT-enabled [5+4]/[3,3]/[2+2] cascade with vinyl cyclopropanes enables one-pot access to complex pyridine-fused, bridged pentacycles scaffolds that are widely embedded in bioactive molecules, but whose synthesis has remained challenging owing to scarcity of efficient strategies.

Medium-sized bridged heterocycles are highly attractive structural motifs in bioactive natural products and medicinal chemistry. However, their broader exploration remains limited due to the lack of concise and modular synthetic strategies, as their synthesis is challenged by unfavorable enthalpic and entropic constraints. Herein, we report an energy transfer (EnT)-catalyzed intermolecular (5 + 4) dearomative cycloaddition of furans with vinyl cyclopropanes, providing direct access to (Z)-10-oxabicyclo[5.2.1]deca-3,8-diene scaffolds in a single step. Visible light triplet sensitization unlocks a distinct diene-type 1,4-biradical activation mode in furans. This triplet-state reactivity enables intermolecular higher-order (5 + 4) cycloadditions that remain inaccessible under conventional thermal activation. Mechanistic investigations support an energy transfer pathway and provide insights into the origin of the observed regioselectivity. The resulting partially unsaturated cycloadducts offer multiple synthetic handles for downstream functionalization, enabling rapid and modular incorporation of heterobicyclo[5.2.1]alkane motifs and highlighting their potential as versatile building blocks in synthetic chemistry.

In this review, the synthesis of optically active cyclopropanes from cyclopropenes, via the formation of C–H, C–C and C–heteroatom bonds, is described. The transformations used to access optically act...

Fused cyclopropanes are prominent motifs in bio-active molecules, yet their incorporation into densely functionalized frameworks remains a significant synthetic challenge. Herein, we report a light-mediated dearomative cyclopropanation of ben-...

Communications Chemistry, Published online: 16 April 2026; doi:10.1038/s42004-026-01972-1Functionalized γ-lactones and cyclopropanes with amide substituents are crucial in chemical and pharmacological processes, yet their synthesis poses significant challenges. Here, the authors introduce a high-throughput protocol using amide–sulfoxonium ylides for efficient annulation reactions, offering a versatile method with broad substrate scope and potential for complex molecule diversification, enhanced by machine learning predictions.

Stereoselective construction of fluorinated cyclopropanes is historically difficult. We present a data-driven copper-catalyzed platform that pairs automated high-throughput experiments with machine learning informed by carbene mechanistic descriptors. The workflow reliably produces highly enantio- and diastereoselective fluorocyclopropanes, scales to gram quantities, and accelerates access to fluorinated drug-like scaffolds—showing how AI and automation can make stereochemical optimization faster and more predictive.

Diazo compounds are among the most versatile intermediates in organic synthesis, enabling high-value transformations such as cyclopropanation, X–H insertion, and heterocycle formation. However, their intrinsic instability and hazardous nature have severely restricted their practical use, particularly at scal