Ligands with 1,10-phenanthroline scaffold for highly regioselective iron-catalyzed alkene hydrosilylation

• Published in: Nature communications Vol. 9; no. 1; pp. 221 - 11
• Main Authors: Hu, Meng-Yang, He, Qiao, Fan, Song-Jie, Wang, Zi-Chen, Liu, Luo-Yan, Mu, Yi-Jiang, Peng, Qian, Zhu, Shou-Fei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.01.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 140/58; 639/638/224/685; 639/638/549/933; 639/638/77/888; Aliphatic compounds; Alkenes; Catalysis; Catalysts; Chemical reactions; Dienes; Heavy metals; Humanities and Social Sciences; Hydrosilylation; Iron; Ligands; Metals; multidisciplinary; Regioselectivity; Scaffolds; Science; Science (multidisciplinary); Selectivity; Styrenes
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-02472-6

Transition-metal-catalyzed alkene hydrosilylation is one of the most important homogeneous catalytic reactions, and the development of methods that use base metals, especially iron, as catalysts for this transformation is a growing area of research. However, the limited number of ligand scaffolds applicable for base-metal-catalyzed alkene hydrosilylation has seriously hindered advances in this area. Herein, we report the use of 1,10-phenanthroline ligands in base-metal catalysts for alkene hydrosilylation. In particular, iron catalysts with 2,9-diaryl-1,10-phenanthroline ligands exhibit unexpected reactivity and selectivity for hydrosilylation of alkenes, including unique benzylic selectivity with internal alkenes, Markovnikov selectivity with terminal styrenes and 1,3-dienes, and excellent activity toward aliphatic terminal alkenes. According to the mechanistic studies, the unusual benzylic selectivity of this hydrosilylation initiates from π – π interaction between the phenyl of the alkene and the phenanthroline of the ligand. This ligand scaffold and its unique catalytic model will open possibilities for base-metal-catalyzed hydrosilylation reactions. Hydrosilylation of alkenes poses substantial challenges in terms of regioselectivity. Here, the authors report iron complexes with 1,10-phenantroline ligand scaffolds which  display benzylic selectivity in the hydrosilylation of internal alkenes and Markovnikov selectivity with terminal styrenes and 1,3-dienes.