7719-02-0Relevant articles and documents
Silaethane XIII. Erzeugung von SiC-Doppelbindungen in der Koordinationssphaere von Eisencarbonylkomplexen
Auner, Norbert,Grobe, Joseph,Schaefer, Thomas,Krebs, Bernt,Dartmann, Mechtild
, p. 7 - 24 (2007/10/02)
The suitability of the vinylsilyliron complexes RSi(Cl)CH=CH2 t (3), Fe(CO)2cp (4)> and of MeSi(Cl)CMe=CH2 (14) as precursors for the generation of silaethane derivatives has been investigated.The starting compounds 1 to 4 and 14 can be obtained from Me(Vi)SiCl2, Ph(Vi)SiCl2, HSiCl3 and MeSiCl3, respectively, by judicious combination of published procedures.They have been characterized by analytical and spectroscopic studies as well as by comparison with known data.The generation of the Si=C intermediates was attempted by treating the vinylsilyl iron complexes with LiBut at low temperatures (-10 deg C).Only with 1 was a smooth reaction observed with formation of the Z/Z dimer 1,3-bis(cyclopentadienyl-dicarbonyliron)-1,3-dimethyl-2,4-dineopentyl-1,3-disilacyclobutane (16) of the expected silaethane MeSi=CHCH2But.This intermediate also seems plausible on the basis of trapping experiments, using 2,3-dimethyl-1,3-butadiene, isoprene or 1,3-cyclohexadiene.However, since 16 is formed as the main product even in the presence of an excess of these dienes, the cyclization of the lithiated precursor ClSiMeCH(CH2But)SiMeCH(Li)CH2But must be regarded as an alternative route to 16.The crystal and molecular structure of 16 indicate a Z/Z configuration of the bulky ring substituents.The disilacyclobutane skeleton is nonplanar with a dihedral angle of 18.7 deg.Similar to other 1,3-disilacyclobutane derivatives, 16 shows a fairly short transannular Si(1)...Si(2) distance of 2.641(1) Angstroem.Due to the -I effect of the phenyl substituent reaction of 2 with LiBut yields oligomeric coupling products, whereas in 3, 4 or 14 for steric reasons LiBut clearly attacks the carbonyl ligand instead of the CC double bond to give black, pyrophoric solids of low solubility.
Macrocyclic polyether compounds
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, (2008/06/13)
Macrocyclic polyether "crown" compounds of the formula EQU1 WHEREIN T is a C2 -C3 alkylene, A is EQU2 R being H or C1 -C18 alkyl, R2 and R3 being independently C1 -C18 alkyl, C2 -C4 alkenyl, or C6 -C14 aryl; Q and Z are independently 1,2-arylene (or saturated derivatives thereof) or substituted 1,2-arylene (or saturated derivatives thereof); a is 0, 1, 2, or 3; b is an integer from 3 to 20; y is 1 or zero; x1, x2, x3, and x4 are integers independently selected to give a 15-60 atom ring. Such crown compounds are generally useful in the formation of complexes with ionic metal compounds, thus making it possible to use certain chemical reagents in media wherein they are normally insoluble.
