A direct and selective synthesis of α,β-unsaturated piperidones by a new palladium-catalyzed cascade carbonylation is described. In the presented protocol, easily available propargylic alcohols react with aliphatic amines to provide a broad variety of interesting heterocycles. Key to the success of this transformation is a remarkable catalytic cleavage of the present carbon–carbon triple bond by using a specific catalyst with 2-diphenylphosphinopyridine as ligand and appropriate reaction conditions. Mechanistic studies and control experiments revealed branched unsaturated acid 11 as crucial intermediate.

中文翻译：

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钯催化通过选择性裂解碳-碳三键进行级联羰基化生成 α,β-不饱和哌啶酮

描述了通过新型钯催化级联羰基化直接选择性合成 α,β-不饱和哌啶酮。在所提出的方案中，容易获得的炔丙醇与脂肪胺反应，提供多种有趣的杂环。这种转化成功的关键是通过使用以 2-二苯基膦吡啶为配体的特定催化剂和适当的反应条件，对现有的碳-碳三键进行显着的催化裂解。机理研究和控制实验表明支链不饱和酸11是关键的中间体。