Direct Syn Addition of Two Silicon Atoms to a C≡C Triple Bond by Si−Si Bond Activation: Access to Reactive Disilylated Olefins

Synthetic strategies to access silacycles

In comparison with all-carbon parent compounds, the incorporation of Si-element into carboskeletons generally endows the corresponding sila-analogues with unique biological activity and physical-chemical properties. Silacycles have recently shown promising application potential in biological chemistry, pharmaceuticals industry, and material chemistry. Therefore, the development of efficient methodology to assemble versatile silacycles has aroused increasing concerns in the past decades. In this review, recent advances in the synthesis of silacycle-system are briefly summarized, including transition metal-catalytic and photocatalytic strategies by employing arylsilanes, alkylsilane, vinylsilane, hydrosilanes, and alkynylsilanes, etc. as starting materials. Moreover, a clear presentation and understanding of the mechanistic aspects and features of these developed reaction methodologies have been high-lighted.

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.