1198-01-2Relevant articles and documents
Hydrostannation of 1,1-bis(trimethylstannyl)ethylene and some related olefins: First steps toward constructing a karplus-type curve for 3J(Sn-Sn)
Mitchell, Terence N.,Reimann, Werner,Nettelbeck, Christa
, p. 1044 - 1048 (2008/10/08)
Four trimethylstannyl-substituted alkenes, Me3SnCR=CH2 (R = Ph, t-Bu, Me3Si, Me3Sn), were hydrostannated by trimethyltin hydride. Though all four olefins reacted, that with R = t-Bu was consumed only very slowly. The major product was, as expected, the 1,2-distannylalkane RCHSnMe3CH2SnMe3; however, for R = Me3Sn 40% of the regioisomer (Me3Sn)2CRCH3 was obtained compared with at most 5% in the other cases. On the basis of NMR data (1H, 13C, 29Si, 119Sn) for distannylalkanes and for Me3SnCH2CH2SiMe3 the preferred rotamers in solution (CDCl3) at room temperature have been determined. The value of 3J(Sn-Sn) corresponding to a dihedral angle of 180° is ca. 1100 Hz, while an angle of 90° apparently corresponds to a value near zero: values of this magnitude are shown by allene-hexamethylditin adducts. First results on bromodemethylated derivatives show that the effect of increasing the electronegativity of the tin moiety is not straightforward.
