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β-酮腈类化合物合成方法研究进展：从传统离子型策略到酰基自由基氢酰化
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Abstract:
β-酮腈类化合物同时含有羰基和氰基两类重要官能团，是有机合成中极具价值的多功能中间体。文章系统综述了β-酮腈类化合物的主要合成策略，包括腈α-位酰化、酮烯醇盐或其等效体的亲电氰化、β-酮羰基化合物直接α-氰化、过渡金属催化羰基化偶联以及氧化偶联等传统非自由基方法。同时，重点总结了近年来自由基和光化学策略在β-酮腈合成中的应用，尤其是醛、苯并噻唑啉、4-酰基汉斯酯和酰氯等酰基自由基来源参与活化烯烃加氢酰化反应的研究进展。现有方法虽已取得显著发展，但仍存在局限，发展以简单易得芳香醛为直接底物、反应条件更温和简洁、无需金属或复杂前体的新型β-酮腈构建方法，仍具有重要的方法学意义和应用价值。
β-Ketonitriles, bearing both carbonyl and cyano functional groups, are highly valuable multifunctional intermediates in organic synthesis. This article summarizes the major synthetic strategies for β-ketonitriles, including classical non-radical approaches such as α-acylation of nitriles, electrophilic cyanation of ketone enolates or their equivalents, direct α-cyanation of β-keto carbonyl compounds, transition-metal-catalyzed carbonylative coupling, and oxidative coupling reactions. Particular attention is given to recent advances in radical and photochemical strategies, especially hydroacylation reactions of activated alkenes enabled by acyl radicals generated from aldehydes, benzothiazolines, 4-acyl Hantzsch esters, and acyl chlorides. Although significant progress has been made with existing methodologies, limitations remain. Developing novel methods for constructing β-ketonitriles using readily available aromatic aldehydes as direct substrates under milder and simpler conditions, without requiring metals or complex precursors, continues to hold important methodological significance and practical value.
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