13155-00-5Relevant articles and documents
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Brooks, C. J. W.,Harvey, D. J.
, p. 193 - 204 (1971)
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Oxo(trisyl)borane (Me3Si)3C-BO as an Intermediate
Paetzold, Peter,Neyses, Stephan,Geret, Laurence
, (2008/10/08)
The acyclic trisylboranes R-B(OSiMe3)-Cl (4a) and R-B(OH)-H (5a) and thecyclic boranes (-RB-O-CO-CO-O) (1a) and (-RB-O-RB-O-SO2-O-) (6a) [R=(Me 3Si)3C, Trisyl ] are thermolyzed in the gasphase to give well-defined products. The tris(trisyl)boroxine (-RB-O-)3 (2a) is formed from 4a and 5a at 140 and 160°C, respectively, besides Me3SiCl and H2, respectively, whereas the six-membered ring [-BMe-CH(SiMe3)-SiMe2-O-SiMe2-CH2-](8) is the product from 1a and 6a at 600 and 700°C, respectively , besides CO/CO2 and SO3, respectively. The oxoborane R-BO is presumablya common intermediate. It is stabilized at the lower temperature by cyc lotrimerization to give 2 and at the higher temperatur by a sequence of several intramolecular steps: a 1,3-silyl shift along the chain C-B-O, an exchange of Me and Me3SiO along the chain Si-C-B, and a C-H addition to the B=C double bond; the steps can be rationalized by analogous known reactions. The gas-phase thermolysis at 600°C of the dioxaboracyclohexenes (-BR-O-CH'=CH-CRR'-O-) (7b-d; R=Me, iPr, tBu; R'=Me) yields the boroxines (RBO)3 and the enones Me-CO-CH=CHR-Me; the cyclohexene 7e (R=Me; R'=CF3) is not decomposed at 600°C.
