Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
Org Biomol Chem. 2022 Sep 21;20(36):7188-7215. doi: 10.1039/d2ob01326f.
Spiro-connected hexahydropyrimidine-2,4,6-trione heterocyclic rings have received increasing attention from the viewpoint of biological activity and synthetic methods due to the importance of the rigid heterocyclic system and unique orientation of the functional substituents. Since 1900, numerous studies have exploited the synthesis of various spirobarbiturate-fused carbo- and heterocycles by applying different strategies. Due to the importance of barbiturate-based olefins as activated alkenes, these substrates have been utilized in many reactions. In addition, the nucleophilic addition of 1,3-disubstituted barbituric acid to different electrophiles has been applied to prepare highly functionalized spirobarbiturate scaffolds. This short review highlights various strategies for synthesizing spirobarbiturate-fused 3- to 7-membered carbo- and heterocyclic rings and some catalytic diastereoselective and enantioselective chemical reactions to access chiral compounds. The sections are divided by the incorporation of 3- to 7-membered heterocyclic or carbocyclic rings into a spirobarbiturate scaffold, and are presented in different subsections depending on the mechanistic details.
螺环连接的六氢嘧啶-2,4,6-三酮杂环由于刚性杂环系统和独特的功能取代基取向的重要性，从生物活性和合成方法的角度受到越来越多的关注。自 1900 年以来，人们通过应用不同的策略，对各种螺巴比妥酸稠合碳环和杂环的合成进行了大量研究。由于基于巴比妥酸的烯烃作为活化烯烃的重要性，这些底物已被用于许多反应中。此外，1,3-二取代巴比妥酸对不同亲电试剂的亲核加成已被应用于制备高度功能化的螺巴比妥酸支架。这篇简短的综述重点介绍了合成螺巴比妥酸稠合的 3 至 7 元碳环和杂环的各种策略，以及一些催化的非对映选择性和对映选择性化学反应，以获得手性化合物。各部分根据 3 至 7 元杂环或碳环并入螺巴比妥酸支架的情况进行划分，并根据详细的机理在不同小节中呈现。
