150479-94-0Relevant articles and documents
Organosubstituted 1,1'-Spirobisiloles and 1,1'-Spirobigermoles by Fourfold Organoboration of Tetra-1-alkynylsilanes and -germanes
Koester, Roland,Seidel, Guenter,Klopp, Ingo,Krueger, Carl,Kehr, Gerald,et al.
, p. 1385 - 1396 (2007/10/02)
Si(CCR)4 R)4 nonatetraenes via the mono- and bisethyloboration compounds 3 or 4 (e.g. 3b, 4c) with different rates: Ge >> Si; Me > Ph.For comparison, compounds Sn(CR)4 react with Et3B in the absence of a solvent to mixtures of various spirotin compounds (5f, 5g, 6f, 8f, 9g, 10g, 11g) of which only 9g (R = Ph) corresponds to the spirosilanes and -germanes.This is the result of effective competition between intramolecular and intermolecular organoboration in the case of the tetra-1-alkynyltin compounds.The protodeborylation of 1a, b and 2d, e with MeCO2H leads to 12a, b and 13d, e, respectively. 12a isomerises by UV irradiation to allyl isomers 12a'.From 12a with 2 equiv. of maleic anhydride the 1:2 addition compound 14a is obtained, the autaddition of 12a, d leads to 15a, d.Spiro compound 12a reacts with (OC)5Fe or CpCo(C2H4)2 to give the cyclodiastereomeric η4-complexes 2-12a (16a1-a4; X-ray structure analysis of meso-16a1), (OC)3Fe-12a (17a) and (CpCo)2-12a (18a1-a4). - All products were characterized by multinuclear NMR, including measurements of the coupling constants 1J(13C13C), 2J(29Si29Si), nJ(29Si13C) and nJ(119Sn13C). Key Words: Silanes, tetra-1-alkynyl- / Germanes, tetra-1-alkynyl- / 1,1-Ethyloboration, intermolecular / 1,1-Vinyloboration, intramolecular / Spirosilanes / Spirogermanes / Protodeborylation / Transition metals, η4-complexes of
