Pd-Catalyzed Regioselective Si–C Bond Cleavage: Maximizing Chemo-Divergence in (4 + 2) Silacyclization Reactions of Alkynals

• Published in: ACS catalysis Vol. 15; no. 12; pp. 10808 - 10817
• Main Authors: Wang, Xing-Ben, Si, Jia-Wei, Pu, Meng-Ling, Guo, Jun-Jie, Xu, Zheng, Li, Li, Shi, Zhuangzhi, Kwong, Fuk Yee, Xu, Li-Wen
• Format: Journal Article
• Language: English
• Published: American Chemical Society 20.06.2025
• Subjects: palladium catalysis; silacycles; Si−C bond activation; cyclization; divergent catalysis
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.5c02870

Precise control of catalyst systems to achieve chemodivergent synthesis from identical starting materials remains a fundamental challenge in catalysis and synthetic chemistry. Herein, we report a ligand-driven Pd-catalyzed regio- and chemodivergent (4 + 2) silacyclization reactions of benzosilacyclobutenes with unsymmetric alkynals, enabling the synthesis of all four dihydrobenzo­[c]­siline derivatives with remarkable selectivity. Each phosphine ligand uniquely dictates the reaction pathway, demonstrating unparalleled chemo-control and addressing long-standing challenges, including uncontrollable Si–C­(sp 2 ) or Si–C­(sp 3 ) bond cleavage and selective α-site or β-site addition to unsymmetrical alkynes. By leveraging steric and electronic properties of ligands, we achieve high yields and good selectivities, supported by mechanistic insights from DFT calculations. This strategy establishes a versatile platform for silacycle synthesis, with broad potential for atom-economics, chemistry, and materials science.