Graduate School of Pharmaceutical Sciences , Kyoto University , Sakyo-ku , Kyoto 606-8501 , Japan.
Org Lett. 2018 Aug 3;20(15):4401-4405. doi: 10.1021/acs.orglett.8b01524. Epub 2018 Jul 23.
Gold(I)-catalyzed cascade cyclization of 1,4-diyn-3-ones with a pyridine N-oxide enabled direct construction of a benzo[6,7]cyclohepta[1,2- b]furan scaffold with the formation of four bonds. This reaction would proceed through oxidative cyclization, alkynyl migration, and 5- endo-dig type cyclization. Synthesis of benzotropone-fused naphtho[1,2- b]furans through a two-step sequence, including epoxidation and In(OTf)-catalyzed intramolecular carbon-carbon bond formation, is also presented.
金（I）催化的 1,4-二炔-3-酮与吡啶 N-氧化物的级联环化反应，可直接构建具有四条键形成的苯并[6,7]环庚[1,2-b]呋喃骨架。该反应通过氧化环化、炔基迁移和 5-endo-dig 型环化进行。通过两步序列，包括环氧化和 In(OTf)催化的分子内碳-碳键形成，也展示了苯并噻吩并[1,2-b]呋喃的合成。
