Notizen: Synthesis and Structure of an 1,3-Dibora-2,5-disilacyclohexane Derivative

Abstract

Hydroboration, 3,3-Dimethyl-(e)-1-chlorodimethylsilyl-1-chloro-dimethylaminoboryl-butene-1,1,3-Bis(dimethylamino-2,2,5,5-tetramethyl-4,6-bis-(t-butylethylene)-1,3-dibora-2,5-disilacyclohexane Hydroboration of chlorodimethyl(3.3-dimethylbutynyl)silane with HBCl2/BCl3 yields 3.3-dimethyl-(e)-1-chlorodimethylsilyl-1-dichloroboryl)-butene-1 (1 a), in which a chlorine atom at the boron can be substituted using Me3SiNMe, to give the corresponding chlorodimethylaminoboryl derivative 1 b. Dehalogenation of 1 b with Na/K alloy does not lead to the three-membered ring compound 2, but surprisingly yields the 1,3-dibora-disilacyclohexane derivative 3. The X-ray structure analysis shows a six-membered ring with a chair conformation, a small angle B 1–Si 2–B 1′ = 95.4(1)°, and long Si–B bonds (2.038 Å).