| Abstract
| - A new methodology, which is compatible with the use of reactive organometallic reagents, hasbeen developed for the use of carbosilane dendrimers as soluble supports in organic synthesis.Hydroxy-functionalized dendritic carbosilanes Si[CH2CH2CH2SiMe2(C6H4CH(R)OH)]4 (G0-OH,R = H or (S)-Me) and Si[CH2CH2CH2Si[CH2CH2CH2SiMe2(C6H4CH(R)OH)]3]4 (G1-OH, R = H or(S)-Me) were prepared and subsequently converted into the esters Si[CH2CH2CH2SiMe2(C6H4CH(R)OC(O)CH2Ph)]4 (R = H or (S)-Me) and Si[CH2CH2CH2Si[CH2CH2CH2SiMe2(C6H4CH(R)OC(O)CH2C6H4R‘)]3]4 (R = H and R‘ = H or R = (S)-Me and R‘ = H or R = H and R‘ = Br). As anexample the latter compound was functionalized under Suzuki conditions. The functionalizedcarboxylic acid was obtained in high yield after cleavage from the dendritic support. Moreover, theester functionalized dendrimers were converted to the corresponding zinc enolates followed by acondensation reaction with an imine to a β-lactam in excellent yield and purity. Furthermore, itwas demonstrated that a small combinatorial library of β-lactams could be prepared starting froma carbosilane dendrimer functionalized with different ester moieties. These results show thatcarbosilane dendrimers can be applied as soluble substrate carriers for the generation of lowmolecular weight organic molecules. In combination with nanofiltration techniques, separation andrecycling of the dendrimers can be realized.
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