Synthesis of Hexahydrobenzo[<i>b</i>]pyrimido[4,5-<i>h</i>][1,6]naphthyridines via an Intramolecular Hetero-Diels−Alder Reaction
作者:Fengzhi Yang、Lianyou Zheng、Jinbao Xiang、Qun Dang、Xu Bai
DOI:10.1021/cc100018b
日期:2010.7.12
Method development was completed for a strategy to access a novel pyrimidine-fused heterocyclic scaffold. The key step for this synthetic route entails an intramolecular inverse electron demand hetero-Diels-Alder reaction of imines or iminiums formed in situ from allylaminopyrimidinealdehydes 3 and anilines. The reactions provided exclusively cis-configuration products 6. Products 6 were readily precipitated
A Cascade Reaction with Iminium Ion Isomerization as the Key Step Leading to Tetrahydropyrimido[4,5-<i>d</i>]pyrimidines
作者:Lianyou Zheng、Fengzhi Yang、Qun Dang、Xu Bai
DOI:10.1021/ol703049j
日期:2008.3.1
A novel cascade reaction of aminopyrimidines 1 with N-alkyl amino acids or analogues was investigated. The keys to this cascade are the isomerization of an iminium ion formed between the aldehyde group in pyrimidine and the secondary amine of an amino acid, and subsequent cyclization to the neighboring amino group. This sequence could be useful in the synthesis of novel tetrahydropyrimido[4,5-d]pyrimidine