Sunday, July 30, 2006

Organometallics, 25 (14), 3428 -3434, 2006

Convergent Synthesis and Characterization of Organotin Dendrimers Sn{(CH2)nSn[(CH2)4SnPh3]3}4 (n = 3, 4)

Herbert Schumann,* Yilmaz Aksu, and Birgit C. Wassermann


The reaction of the haloalkyltin trihalides Br(CH2)3SnBr3 and Br(CH2)4SnBr3 with 3 equiv of but-3-enylmagnesium bromide yielded Br(CH2)3Sn(CH2CH2CH=CH2)3 (3) and Br(CH2)4Sn(CH2CH2CH=CH2)3 (4). Both dendritic branches can be converted into their corresponding Grignard reagents, whose consequent treatment with 0.25 M amounts of SnCl42)3Sn(CH2CH2CH=CH2)3]4 (5) and Sn[(CH2)4Sn(CH2CH2CH=CH2)3]4 (6), respectively. The subsequent hydrostannation of 5 and 6 delivered Sn{(CH2)3Sn[(CH2)4SnPh3]3}4 (7) and Sn{(CH2)4Sn[(CH2)4SnPh3]3}4 (8) as dendrimers of the second generation. All compounds were characterized by elemental analysis, 1H, 13C, and 119Sn NMR spectroscopy, and MALDI-TOF mass spectrometry. resulted in the formation of the dendrimers Sn[(CH

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