Tandem Michael Addition/Aldol Reaction of Allenic Ketones with Alkyl Vinyl Ketones: Versatile Synthesis of 2-Alkynyl 1,5-Diketones, 4-Alkynyl-3-hydroxycyclohexanones and 4-Alkynylcyclohexenones
作者:Deepika Malhotra、Le-Ping Liu、Gerald B. Hammond
DOI:10.1002/ejoc.201001161
日期:2010.12
alkynylenolate was investigated in the reactions of allenic ketones and vinylketones. We found that different products could be obtained under different conditions. The tetrabutylammonium fluoride (TBAF)-mediated Michael addition of allenic ketones to vinylketones gave 2-alkynyl 1,5-diketones as the product. Under stronger basic conditions, a tandem Michael addition/aldol reaction of the two starting materials
在烯酮和乙烯基酮的反应中研究了炔基烯醇酸酯的反应性。我们发现在不同的条件下可以得到不同的产品。四丁基氟化铵 (TBAF) 介导的烯酮与乙烯基酮的迈克尔加成得到 2-炔基 1,5-二酮产物。在强碱性条件下,两种原料在一锅内发生串联迈克尔加成/羟醛反应,低温下可分离出4-炔基-3-羟基环己酮,而室温下可得到4-炔基环己烯酮。应注意的是,即使使用乙基乙烯基酮作为迈克尔受体,也仅从反应中分离出一种 4-炔基-3-羟基环己酮的非对映异构体,如通过 1 H 和 13 C NMR 光谱测定。
Palladium‐Catalyzed Cyclizative Borylation of Allenyl Ketones through Carbene Boryl Migratory Insertion: Access to Densely Substituted Furyl Boronates
作者:Kang Wang、Yan Xu、Jianbo Wang
DOI:10.1002/chem.202203697
日期:2023.3
A highly efficient Pd-catalyzed cyclizative borylation reaction of allenyl ketones has been developed. The transformation is based on carbene boryl migratoryinsertion using starting materials that are modularly assembled from raw building blocks. This borylation reaction is a reliable method to synthesize various borylated furans, from which previously hard-to-obtain tetra-substituted furans can be