For over a century, the structures and reactivities of strained organic compounds have captivated the chemical community. Whereas triple-bond-containing strained intermediates have been well studied, cyclic allenes have received far less attention. Additionally, studies of cyclic allenes that bear heteroatoms in the ring are scarce. We report an experimental and computational study of azacyclic allenes, which features syntheses of stable allene precursors, the mild generation and Diels–Alder trapping of the desired cyclic allenes, and explanations of the observed regio- and diastereoselectivities. Furthermore, we show that stereochemical information can be transferred from an enantioenriched silyl triflate starting material to a Diels–Alder cycloadduct by way of a stereochemically defined azacyclic allene intermediate. These studies demonstrate that heteroatom-containing cyclic allenes, despite previously being overlooked as valuable synthetic intermediates, may be harnessed for the construction of complex molecular scaffolds bearing multiple stereogenic centres.

一个多世纪以来，紧张的有机化合物的结构和反应活性吸引了化学界。尽管已经对含三键的应变中间体进行了充分的研究，但环状亚丙基却很少受到关注。另外，缺乏对在环中带有杂原子的环状烯的研究。我们报告了对氮杂环丁烯的实验和计算研究，其特征在于合成了稳定的烯异戊烯前体，所需环烯的温和生成和Diels-Alder捕集，以及对所观察到的区域和非对映选择性的解释。此外，我们表明，立体化学信息可以通过立体化学定义的氮杂环丁烯中间体从富集对映体的三氟甲磺酸硅酯原料转移至Diels-Alder环加合物。