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Cu-Catalyzed Stereo- and Regioselective Diborylation and trans-Protoborylation of 1,3-Enynes

Sat, 28 Feb 2026 15:00:00 GMT

Title: Cu-Catalyzed Stereo- and Regioselective Diborylation and trans-Protoborylation of 1,3-Enynes Author(s): Lee, Yeonjoo; Kim, Minseop; Lee, Dohun; Lee, Yunmi; Seo, Sangwon; Jung, Byunghyuck Abstract: As multifunctional chemical tools, organodiboron compounds present an important challenge in organic synthesis, with respect to their synthesis and functionalization. Although readily available 1,3-enynes have been employed as a platform for various regioselective difunctionalization reactions, the diborylation reactions of 1,3-enynes remain limited, and the installation of a CF3 group is often a prerequisite. In this study, we report a copper-catalyzed selective diborylation reaction of 1,3-enynes to access synthetically useful 1,1- and 1,4-diborylalkenes. The synthetic utility of this method is demonstrated by a gram-scale synthesis of a natural antifouling agent. Furthermore, the Cu-catalyzed trans-protoborylation reaction of aryl-substituted (Z)-enynes is reported. The thorough computational studies and the deuterium-labeling experiments provide insights into the reaction mechanism and the regio- and stereoselectivity of diborylated products.

NiH-Catalyzed Enantioconvergent α-Alkenylation of Carbonyl Compounds via Markovnikov Alkyne Hydronickellation

Tue, 31 Mar 2026 15:00:00 GMT

Title: NiH-Catalyzed Enantioconvergent α-Alkenylation of Carbonyl Compounds via Markovnikov Alkyne Hydronickellation Author(s): Nam, Hyeontaek; Jang, Seji; Kim, Dongwook; Seo, Sangwon Abstract: β-Methylene carbonyl motifs constitute privileged structural frameworks that play vital roles as a pharmacophore and serve as key intermediates in the assembly of architecturally complex molecules. Despite their synthetic importance, asymmetric approaches for their preparation remain scarce and are largely confined to substrate-controlled or stoichiometric chiral auxiliary methods. Herein, we report a nickel hydride-catalyzed enantioconvergent α-alkenylation of carbonyl compounds with alkynes, providing a direct and general route to α-chiral β-methylene carbonyl derivatives. The transformation proceeds via Markovnikov-selective alkyne hydronickellation followed by nickel-radical recombination to forge the α-stereogenic center, delivering the desired products with high levels of regio- and enantioselectivity. The protocol accommodates a wide range of alkynes and α-halocarbonyl partners, displays excellent functional group tolerance, and can be applied to the modification of biologically relevant molecules. Mechanistic investigations indicate that a partially protic Ni(II)H species governs the observed regioselectivity, while enantio-discrimination occurs during the radical capture step. This work establishes NiH catalysis as a versatile platform for expanding the synthetic repertoire for enantioenriched β-methylene carbonyl architectures. © 2026 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.

Post-functionalization of polyethers by photoinduced C-H amidation via polar-radical relay

Thu, 31 Jul 2025 15:00:00 GMT

Title: Post-functionalization of polyethers by photoinduced C-H amidation via polar-radical relay Author(s): Baek, Seung Beom; Kim, Youngho; Lee, Wongyu; Seo, Sangwon; Kim, Dongwook; Seo, Myungeun; Chang, Sukbok Abstract: The C-H functionalization of polymers enables the direct incorporation of new functional groups into polymer backbones, presenting significant opportunities for the upcycling of commodity polymers. However, developing reactions that achieve selective functionalization while preserving the intrinsic features of polymers and avoiding undesirable structure deformation remains a considerable challenge. In this study, we present a transition metal-free post-functionalization approach for polyethers via a photoinduced alpha-C-H amidation reaction. This strategy provides a route to previously unattainable alpha-amino polyethers, which exhibit distinct physical properties from those of the parent polymer. By leveraging a polar-radical relay mechanism, we effectively incorporate C-N bonds into the polyether backbone while suppressing degradation and cross-linking. Conducted under mild and convenient conditions, this approach demonstrates significant site selectivity at the ethereal alpha-position, even in the presence of other types of C-H bonds, achieving tailed post-functionalization of macromolecules. Furthermore, the present strategy holds promise for broader applications, including the amidative degradation of commodity polymers and transformation of polyethylene glycol (PEG) network.

Real-Time Visualisation of Reaction Kinetics and Dynamics: Single-Molecule Insights into the Iminium-Catalysed Diels-Alder Reaction

Fri, 31 Oct 2025 15:00:00 GMT

Title: Real-Time Visualisation of Reaction Kinetics and Dynamics: Single-Molecule Insights into the Iminium-Catalysed Diels-Alder Reaction Author(s): Park, Minsoo; Ahn, Yongdeok; Cho, Juhyeong; Jang, Juhee; Lee, Wonhee John; Seo, Sangwon; Lee, Sunggi; Seo, Daeha Abstract: Investigation of the fundamental microscopic processes occurring in organic reactions is essential for optimising both organocatalysts and synthetic strategies. In this study, single-molecule fluorescence microscopy was employed to study the Diels-Alder reaction catalysed by a first-generation MacMillan catalyst, providing direct insights into its kinetic dynamics. This reaction proceeds via a series of reversible processes under equilibrium conditions (S -><- IM1 -><- IM2 -> P, IM1 and IM2: N,O-acetal and iminium ion intermediates, respectively). The individual reaction trajectories of single molecules were directly observed in real-time, and the kinetic transitions between the different states were quantitatively analysed using a hidden Markov model, thereby enabling precise determination of the kinetic rate constants and transition probabilities at the single-molecule level. In particular, the unique structural features of the MacMillan catalyst were probed to reveal how specific interactions stabilise the reaction intermediates and influence their kinetic behaviours. These findings highlight the importance of single-molecule fluorescence microscopy in understanding the fundamental mechanisms of organic reactions and guiding the rational design of more effective catalysts.