Tandem Synthesis of Linear Hydridopolycarbosilanes and Postfunctionalization by a Calcium Catalyst

• Published in: Macromolecules 2023-12, Vol.56 (23), p.9550-9558
• Main Authors: Zhao, Lanxiao, Deng, Peng, Gong, Xun, Cheng, Jianhua
• Format: Article
• Language: English
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.3c02049

Recent years have witnessed great progress in the application of calcium-based catalysts in a variety of organic transformations, including hydrofuctionalization, dehydrogenative coupling, and C–H activation. However, these efficient protocols in polymer synthesis remain much less explored. Here, we report the selective bis-hydrosilylation of dienes with bis-hydrosilanes in the presence of scorpionate-supported calcium benzyl complex [(TpAd,iPr)­Ca­(p-CH2–C6H4-Me)­(THP)] (TpAd,iPr = hydrotris­(3-adamantyl-5-isopropyl-pyrazolyl)­borate, THP = tetrahydropyran) (1) to obtain linear polycarbosilanes containing a reactive SiH2 unit in the main chain. Furthermore, complex 1 can also catalyze the dehydrogenative silylation of terminal alkyne, silylamination of aniline, and C–H activation of 1-methyl-1H-indole, with the Si–H bonds in polycarbosilanes to allow the introduction of 35–65% new side chains in these polymers. The resulting new polymers contain unusual units including SiH–(CCPh), SiH–(NHAr), and SiH–(indole), whose presence is confirmed by NMR and IR spectra.