Palladium Catalyzed C3-(sp)-H Alkenylation of Pyrroles via a Benzothiazole Directing Group: A Direct Access to Organic Thermally Activated Delayed Fluorescence Materials.

A Pd (II)-catalyzed direct C3-(sp)-H alkenylation of heteroarenes using benzothiazole as a directing group was successfully achieved. A wide range of 2--alkylpyrroles undergo an oxidative coupling with a variety of acrylates to furnish highly regio- and chemoselective E-alkenylation products at the C3 position. An important intermediate complex has been isolated and characterized so as to have an insight into the mechanism.

Access to Hetero-Benzyl Scaffolds via Transient-Ligand-Enabled Direct γ-C(sp)-H Arylation of 3-Methylheteroarene-2-Carbaldehydes.

An efficient and straightforward method has been developed for the synthesis of β-benzyl-substituted 5-membered heterocyclic carbaldehydes via transient directing-group-enabled direct γ-C(sp)-H arylation of 3-methylheteroarene-2-carbaldehydes. A wide range of 3-methylheteroarene carbaldehydes undergo coupling with a variety of aryl iodides, including less reactive iodo pyridine derivatives to provide a library of highly selective functionalized products in good to excellent yields. Some of these products have been successfully utilized in synthesizing useful synthetic intermediates.