A Dual Cobalt-Photoredox Catalytic Approach for Asymmetric Dearomatization of Indoles with Aryl Amides via C-H Activation.

In this study, we unveil a novel method for the asymmetric dearomatization of indoles under cobalt/photoredox catalysis. By strategically activating C-H bonds of amides and subsequent migratory insertion of π-bonds present in indole as reactive partner, we achieve syn-selective tetrahydro-5H-indolo[2,3-c]isoquinolin-5-one derivatives with excellent yields and enantiomeric excesses of up to >99 %. The developed method operates without a metal oxidant, relying solely on oxygen as the oxidant and employing an organic dye as a photocatalyst under irradiation.

Rhodium-Catalyzed Annulations and Heck Coupling/Aza-Michael Addition for the Synthesis of Benzothiadiazinoisoquinoline 6,6-Dioxides and Benzothiadiazinoisoindole 5,5-Dioxides, Respectively.

A new and efficient protocol has been demonstrated for the synthesis of benzothiadiazinoisoquinoline 6,6-dioxides and benzothiadiazinoisoindole 5,5-dioxides in good to excellent yields. These compounds are formed through a sequential Rh(III)-catalyzed C-H cyclization of dihydrophenylbenzothiadiazine 1,1-dioxides with alkynes and oxidative Heck coupling/aza-Michael addition of dihydrophenylbenzothiadiazine 1,1-dioxides with acrylates, respectively.

Rh(III)-Catalyzed Oxidative C-2 Coupling of -Pyridinylindoles with Benzo[]thiophene 1,1-Dioxides via C-H Bond Activation.

An efficient Rh(III)-catalyzed cross-dehydrogenative coupling of -pyridinylindoles with benzo[]thiophene 1,1-dioxides has been developed through directing-group-assisted C-H activation. This transformation constructs a new C-C bond from two inert C-H bonds in a one-pot reaction. The present reaction is compatible with various functional groups with respect to indoles and benzothiophene[] 1,1-dioxides.

Catalyst-free 1,6-conjugate addition of indoles and 4-hydroxycoumarins to -quinone methides: synthesis of unsymmetrical triarylmethanes.

The catalyst-free 1,6-conjugate addition of indoles and 4-hydroxycoumarins to para-quinone methides is reported. This protocol allowed us to access a range of unsymmetrical triarylmethanes in good to excellent yields. The outlined procedure is operationally simple, efficient, atom and step economical.