Asian Journal of Organic Chemistry最新文献

The rapid construction of densely functionalized molecules through the exploration of versatile multitasking building blocks holds significant synthetic potential for pharmaceuticals, agrochemicals, and advanced materials. Among these, 1,2,4-oxadiazol-5(4H)-ones have emerged not only as key scaffolds in biologically active molecules but also as highly adaptable synthons, enabling diverse synthetic transformations for the concise and selective assembly of functionalized architectures. Over the past decades, the reactivity profile of 1,2,4-oxadiazol-5(4H)-ones has been greatly expanded, facilitating their use as O- or N-nucleophiles, nitrogen sources for direct C–H functionalization, directing groups, and internal oxidizing directing groups. These attributes allow for the efficient synthesis of diverse heterocyclic systems and complex molecular frameworks under mild and sustainable conditions. This review comprehensively summarizes recent advances in the synthetic applications of 1,2,4-oxadiazol-5(4H)-ones, covering their roles as bifunctional reagents, coupling partners, and redox-active auxiliaries in transition-metal-catalyzed and metal-free transformations. We also provide a critical outlook on future directions, including enantioselective catalysis, photoredox and electrochemical applications, and the integration of oxadiazolones in the synthesis of bioactive molecules and functional materials. It is anticipated that this review will inspire further innovation in the design and application of multitasking building blocks in synthetic chemistry.

The tricyclic ketal scaffold, found in bioactive natural products such as bullataketals A/B, represents a synthetically challenging yet pharmacologically important structural motif. The detailed mechanism to construct the tricyclic ketal core and mechanistic basis for its regioselectivity are unresolved. Here, we employ density functional theory (DFT) calculations to elucidate the plausible reaction pathways and rationalize the observed product distribution. Potential energy surface (PES) analysis reveals the critical intermediates and transition states governing the cycloaddition, and evaluation of the competing transition states demonstrates the regioselectivity of the reaction. Our computational study validates the proposed biosynthetic hypothesis, offering valuable insights for the synthesis design of complex tricyclic ketal core-containing natural products.

The small nucleoside molecule LJ-4827 exhibited potent kinase inhibition and in vitro anticancer activity. Driven by bio-isosteric principles, we synthesized LJ-5157, which also demonstrated high kinase selectivity and anticancer efficacy. To further expand the structural diversity of bioactive nucleoside analogs, we developed a metal-free, late-stage strategy for converting terminal alkynes to nitriles using tert-butyl nitrite (^tBuONO). By substituting 2-picoline N-oxide with N-methylmorpholine N-oxide (NMO) as the oxidant, we accomplished efficient nitrile formation in nucleoside scaffolds. This approach broadens the scope of alkyne cleavage chemistry and offers a practical route for analog diversification.

Among various types of solvents used in organic synthesis for organic transformations, halogenated solvents have been widely used in industries and laboratories. In many reports, it has been noticed that these halogenated solvents have been involved themselves and are utilized as surrogates for the organic reactions, and thus, the examples have been summarized in the present article, covering the commonly used solvents bearing chlorine, like chloroform, dichloromethane, and dichloroethane, which have been discussed in detail.