Assembly of a Benzo‐Fused Bridged Ketone Scaffold from 1, 5, 10‐Enediynes through One‐Pot Ruthenium‐Catalyzed Cyclization/Iodine‐Mediated Oxidative Ring Expansion. Issue 20 (18th April 2017)

• Record Type: Journal Article
• Authors: Yamamoto, Yoshihiko; Nishimura, Kei‐ichiro; Mori, Shota; Shibuya, Masatoshi
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 20(2017)
• Page Start: 5494
• Page End: 5497
• Publication Date: 2017-04-18
• Subjects: bridged ketones -- cyclization -- enediynes -- ring expansion -- ruthenium; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201700493
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: In the presence of a cationic Ru catalyst, 1, 6‐diynes bearing a terminal styryl moiety underwent [2+2+2] cyclization to produce dehydrobiphenylenes fused with a five‐membered ring. Although the cycloadducts were unstable toward purification, their one‐pot iodine‐mediated ring expansion successfully afforded unprecedented bridged ketone products containing a benzo‐fused bicyclo[3.2.1] framework. Abstract : Building bridges : An unprecedented bridged ketone scaffold was assembled by a one‐pot tandem ruthenium‐catalyzed [2+2+2] cyclization/iodine‐mediated oxidative ring expansion. The [2+2+2] cyclization proceeds in the presence of a cationic Ru catalyst in THF at room temperature, and subsequent ring expansion is triggered by the addition of N ‐iodosuccinimide and MeOH to the reaction mixture.