Double CHbondactivation took place efficiently upon treatment of 3‐phenylthiophenes with alkynes in the presence of a rhodiumcatalyst and a copper salt oxidant to form the corresponding naphthothiophene derivatives. Dehydrogenative coupling with alkenes was also found to occur on the phenyl moiety rather than the thiophene ring. These reactions provide straightforward synthetic methods for π‐conjugated
Iridium‐Catalyzed Annulation Reactions of Thiophenes with Carboxylic Acids: Direct Evidence for a Heck‐type Pathway
作者:Guangying Tan、Qiulin You、Jingbo Lan、Jingsong You
DOI:10.1002/anie.201802539
日期:2018.5.22
The functionalization of thiophenes is a fundamental and important reaction. Herein, we disclose iridium‐catalyzed one‐pot annulation reactions of (benzo)thiophenes with (hetero)aromatic or α,β‐unsaturated carboxylic acids, which afford thiophene‐fused coumarin‐type frameworks. Dearomatization reactions of 2‐substituted thiophenes with α,β‐unsaturated carboxylic acids deliver various thiophene‐containing
Benzo-fused tri- to heptacyclic heteroarenes were effectively constructed by the rhodium-catalyzed dehydrogenative coupling of phenylheteroarenes with alkynes. Using alkenes as coupling partners, dehydrogenative alkenylation took place selectively on the phenyl moiety of phenylheteroarenes. Several experiments with deuterium-labeled substrates indicated that double C-H bond cleavages take place even in the reaction with alkenes.