Double Isocyanide Cyclization: A Synthetic Strategy for Two-Carbon-Tethered Pyrrole/Oxazole Pairs

A new strategy for the construction of the compounds with two different heterocycles, linked by a C2-tether via a domino process involving [5 + 1] annulation, ring-opening, and subsequent double isocyanide cyclization, from the reaction of ethyl isocyanoacetate with divinyl ketones (DVKs) has been developed. The chemoselective fragmentation of the cyclohexanone intermediate is the key for the formation of not only the C2-tether but also the two different heterocycles.

本研究开发了一种全新的合成策略，可用于构建由C2连接臂（C2-tether）连接的含两种不同杂环的化合物；该策略以异氰基乙酸乙酯（ethyl isocyanoacetate）与二乙烯基酮（divinyl ketones, DVKs）为原料，经由包含[5+1]环合、开环以及后续双异氰基环合的多米诺串联反应实现。其中，环己酮中间体的化学选择性断裂，不仅是C2连接臂形成的关键，亦是两种不同杂环生成的核心环节。