Synthesis of Azabicyclic Building Blocks for Daphniphyllum Alkaloid Intermediates Featuring N‐Trichloroacetyl Enamide 5‐endo‐trig Radical Cyclizations

Abstract

A general procedure is reported for the synthesis of cis ring fused azapolycyclic compounds bearing an all‐carbon quaternary stereocenter at the ring fusion and an adequate functionalization for the assembly of new rings leading to advanced synthetic intermediates for Daphniphyllum alkaloid synthesis. The key carbon−carbon bond‐forming step in this approach is a radical cyclization of an N‐cycloalkenyl trichloroacetamide derivative involving a tetrasubstituted enamide to achieve polyfunctionalized lactams.

Construction of diverse polycyclic N-heterocycles via cascade allylic amination/Diels–Alder reaction

“…Importantly, this reaction provided rapid access to the hydrobenzo[ cd ]indole skeleton, a key structural motif widely present in a large number of natural products and pharmaceutical agents. 13 …”

Recent progress in the total synthesis of calyciphylline A-type <italic>Daphniphyllum</italic> alkaloid himalensine A

“…、Fukuyama/Yo-koshima课题组 [17] 、翟宏斌课题组 [18] 和邱发洋课题 组 [19] 等先后报道了多个含相邻双季碳及含苯环结构的 Dixon课题组 [36] 和高栓虎课题组 [37] 也先后漂亮地完成 了himalensine A的全合成工作. 此外, Bonjoch课题 组 [38,39] 、Stockdill课题组 [40] 、Hudlicky课题组 [41] 等也 先后开展了一系列适用于himalensine A全合成的关键 骨架构筑探索. 下面将聚焦于介绍2017~2020年针对himalensine A及相关结构的合成研究进展.…”

“…下面将聚焦于介绍2017~2020年针对himalensine A及相关结构的合成研究进展. 图 2 Stockdill课题组 [40] 对于ABC三环骨架的合成研究 Figure 2 Synthesis of the ABC tricyclic ring system by the Stockdill group [40] 图 3 Bonjoch课题组 [38] 对于ABC三环骨架的合成研究 Figure 3 Synthesis of ABC tricyclic ring system by the Bonjoch group [38] 评 述…”