Synthesis and characterization of some organo-all-tin dendrimers with different peripheral substituents

The synthesis of the first all-tin-dendrimer Sn[(CH2)4SnPh3]4 (2) results from complete hydrostannation of tetra(but-3-enyl)stannane (1) with triphenyltin hydride. Selective cleavage of one phenyl group from each dendron of 2 with anhydrous HCl results in Sn[(CH2)4Sn(Cl)Ph2]4 (3), which on treatment with LiAlH4 yields the corresponding hydride derivative Sn[(CH2)4Sn(H)Ph2]4 (4) containing four reactive Sn–H bonds. The cyclopentadienyl derivative Sn[(CH2)4Sn(C5H5)Ph2]4 (5) as well as the transition metal substituted derivatives Sn[(CH2)4Sn{Co(CO)4}Ph2]4 (6), Sn[(CH2)4Sn{Fe(CO)2C5H5}Ph2]4 (7), and Sn[(CH2)4Sn{Mn(CO)5}Ph2]4 (8) have been prepared by coupling of 3 with the appropriate Grignard or sodium derivatives of the transition metal moieties. The new compounds were characterized by elemental analyses, IR, 1H-, 13C- and 119Sn NMR spectroscopy and MALDI-TOF mass spectrometry.