Rhodium-Catalyzed Synthesis of Germoles via the Activation of Carbon–Germanium Bonds

Pd-Catalyzed Hydroxyl-Directed Cascade Hydroarylation/C-H Germylation of Nonterminal Alkenes and Aryl Iodides

Pd-catalyzed cascade hydroarylation and C-H germylation of nonterminal alkenes and aryl iodides enabled by hydroxyl assistance have been developed. The key step in this C-H germylation cascade is the formation of a highly reactive oxo-palladacycle intermediate, which markedly restrained the β-H elimination process. Mechanistically, control experiments indicated that the hydroxyl group played an important role in this process. This transformation shows excellent reactivity and selectivity for most substrates investigated.

Modular access to substituted germoles by intramolecular germylzincation

Intramolecular alkyne germylzincation giving access to a wide range of germoles is achieved from triarylhydrogermanes in the presence of diethylzinc and AIBN as radical initiator. The reaction proceeds through activation of the Ge-H bond, leading to a heteroarylzinc intermediate after cyclisation, which can then be involved in a post-functionalisation reaction. Our results show that only 5-endo-dig cyclizations occur, with benzogermoles being exclusively obtained.

Synthesis of Polysubstituted Germoles and Benzogermoles Using a Substoichiometric Amount of Diisobutylaluminum Hydride

We developed a synthetic route to unsymmetrically polysubstituted germoles bearing different substituents from 1-hydrogermyl-4-silyl-1,3-enynes. The reaction proceeded with 0.5 equiv of diisobutylaluminum hydride. Various 2-silylgermoles including benzogermoles were obtained in good to excellent yields. 2-Germylbenzogermoles could be also successfully synthesized from 1-hydrogermyl-4-germyl-1,3-enynes under the same reaction conditions.

Palladium-Catalyzed Synthesis of 2,3-Disubstituted Benzothiophenes via the Annulation of Aryl Sulfides with Alkynes

A new method has been developed for the synthesis of 2,3-disubstituted benzothiophenes involving the palladium-catalyzed annulation of aryl sulfides with alkynes. This convergent approach exhibited good functional group tolerance, providing rapid access to a diverse array of derivatives from simple, readily available starting materials. This protocol can also be used to synthesize 2-silyl-substituted benzothiophenes, which can be used as versatile platforms for the synthesis of 2,3-unsymmetrically substituted benzothiophenes.

Recent developments in synthetic methods for benzo[b]heteroles

Benzo[b]heteroles containing heteroatoms other than nitrogen and oxygen have received considerable attention for their potential applications in materials science. This poses an increasing demand for efficient, selective, and broad-scope methods for their synthesis. This review article summarizes the recent developments in synthetic methods and approaches to access representative members of the benzoheterole family.