Cobalt(III)-Catalyzed Redox-Neutral Coupling of Acrylamides with Activated Alkenes via C–H Bond Activation

Abstract

A cobalt(III)-catalyzed coupling of substituted acrylamides with maleimides in the presence of 30 mol% pivalic acid providing olefin-migrated succinimide derivatives in a redox-neutral manner is described. The coupling reaction was examined with various substituted acrylamides and maleimides. The scope of the C–H alkylation reaction was also examined with substituted acrylates. A possible reaction mechanism involving a five-membered cobaltocycle as a key intermediate is proposed.

Synthesis of Selenoflavones via Ruthenium-Catalyzed Selenylation of Unsaturated Acids

“…Treatment of selenylated acrylic acids 3 with triflic acid at 120 °C for 4 h afforded the selenoflavones 4 in good yields (Scheme ). The structure of 4e was confirmed by single-crystal X-ray analysis (CCDC 2234651; see the Supporting Information). Furthermore, the scope of the present C–H selenylation reaction was examined with various N-substituted acrylamides 5a – 5l under the optimized reaction conditions (Scheme ).…”

Dehydrogenative Cross-Coupling of α,β-Unsaturated Compounds with Unactivated Olefins via Co(III) Catalysis

“…A transition-metal-catalyzed C–H olefination reaction would bypass the need for such functionalized molecules and facilitates the synthesis of the dienes in a high atom and step economical manner . This transformation is already well explored with precious second and third row transition metals such as Pd, Rh, Ir, and Ru. , The exploration of these techniques with less expensive and readily accessible first-row metal catalysts such as cobalt salts has received much attention because of their unique reactivity patterns and low toxicity. In this context, aminoquinoline-assisted cobalt-based C–H activation techniques have been explored using the bidentate template, which can stabilize first-row transition metals at a high oxidation state.…”