124044-73-1Relevant academic research and scientific papers
A 1,3-Methyl Shift along the Unsaturated BCSi Skeleton
Paetzold, Peter,Schmitz, Thomas,Tapper, Alexander,Ziembinski, Ralf
, p. 747 - 750 (2007/10/02)
The synthesis of the methoxyboranes X-(MeO)B-C(SiMe3)3 (1a-d; X= Cl, Br, Ph, PhCH2) is described.The methylenoboranes Me-B=C(SiCH3)(SiMe2Hal) (3a, b), the 2,3-dihydro-1H-1-sila-3-boraindene species 6, and the 1,2,3,4-tetrahydro-1-sila-3-boranaphtalene species 7 are formed by the thermal elimination of MeOSiMe3 from 1a/b or 1c or 1d, respectively.The boranes 3a, b undergo cyclodimerization at the B=C bond at 25 and 69 deg C, respectively, the diboretanes 4a, b being formed.The oxaboretanes 5a, b are isolated from the reaction of 3a, b with Ph2CO.The thermal elimination of MeOSiMe3 from M3'-(MeO)B-C(SiMe3)3 (1g'; Me'=CD3) and subsequent addition of Ph2CO gives the oxaboretanes 5g'/5g''in the ratio of 1:6, showing that an equilibrium Me'-B=C(SiMe3)2 Me-B=C(SiMe3)(SiMe2Me') with a statistical distribution of Me' among seven methyl places is established in the hot tube before Ph2CO finally attacks the double bond.All these results are in accord with the primary formation of the methyleneboranes X-B=C(SiMe3)2 from 1a-d, followed by a 1,3-shift of Me along the unsaturated BCSi skeleton and the subsequent transformation into the isolated products.
