118853-33-1Relevant articles and documents
Sila Heterocycles, XXII. - Diels-Alder Reactions of Dichloro(neopentyl)silaethene with Furans and Rearrangement of the Resulting Bicycles into Monocyclic Si-O Seven-Membered Ring compounds.
Auner, Norbert,Wolff, Astrid
, p. 575 - 580 (2007/10/02)
The reaction of trichloro(vinyl)silane (1) and LitBu (2) initially leads to the α-lithio adduct Cl3SiCH(Li)CH2tBu (3) which can be trapped by trimethylsilyl triflate yielding the C-silylated product . 1,2-LiCl elimination from 3 gives dichloro(neopentyl)silaethene as intermediate.This can be established by insertion of 4 into the Si-O bond of Me3SiOMe to Cl2Si(OMe)CH(SiMe3)CH2tBu (6). 4 is a dienophile of high activity and reacts with the furans 7-9 to give the cycloaddition compounds 10-12.These Diels-Alder products are thermally unstable and decompose slowly at room temperature into the starting furans and tetrachlorodisilacyclobutane (15).Under thermolysis conditions (3d/170 deg C) they rearrange into the monocyclic Si-O seven-membered ring compounds 16-18.A mechanism for the 7-Oxa-2-silabicyclohex-5-en -> 1-Oxa-2-silacyclohepta-4,6-diene rearrangement is proposed. Key Words: Silaethene derivatives/Furans/Cycloaddition reactions/Rearrangements/Sila heterocycles/Diels-Alder reactions