Carbosilanes silicon-containing dendrimers

Catalytic hydrosilylation provides a convenient route to silicon-containing den-drimers. Combinations of hydrosilylation with alkenylation (usually allylation and vinylation) and ethynylation give powerful protocols for the rapid and efficient synthesis of silicon-containing dendrimers (mostly carbosilanes and carbosilox-anes) [4]. This topic has recently been reviewed by Majoral [31] and Schlenk and Frey [32], At present carbosilane dendrimers are the most important class of Si-based dendrimers (cf. also Section 3.2.2). 

The group of Van Leeuwen has reported the synthesis of a series of functionalized diphenylphosphines using carbosilane dendrimers as supports. These were applied as ligands for palladium-catalyzed allylic substitution and amination, as well as for rhodium-catalyzed hydroformylation reactions [20,21,44,45]. Carbosilane dendrimers containing two and three carbon atoms between the silicon branching points were used as models in order to investigate the effect of compactness and flexibility of the dendritic ligands on the catalytic performance of their metal complexes. Peripherally phosphine-functionalized carbosilane dendrimers (with both monodentate... 

---