22407-48-3Relevant academic research and scientific papers
Silaheterocycles, XXV. - (Me3SiO)2Si=CHCH2tBu: A Siloxy-Functionalized Synthetic Equivalent for Dichloropentylsilene
Auner, Norbert,Heikenwaelder, Claus-Ruediger,Ziche, Wolfgang
, p. 2177 - 2186 (2007/10/02)
(Me3SiO)2Si=CHCH2tBu (4) is obtained by the reaction of (Me3SiO)2Si(Cl)CH=CH2 (2) with LitBu.The reaction proceeds via the α-lithiated species 3, which can be intercepted by trimethylsilyl triflate to give 5.Silaethene 4 dimerizes to the E/Z-isomers of disilacyclobutane 7 and adds to Me3SiOMe to give 6.The reactivity of 4 resembles that of Cl2Si=CHCH2tBu (1): A cycloadduct is obtained from the reaction with anthracene, and with 1,3-cyclohexadiene and 1,3-cycloheptadiene mixtures of monosilacyclobutanes (10 and 12) and bicyclic Diels-Alder adducts (9 an 11) are available.Exclusive cycloaddition reactions take place with styrene (formation of 13), 2,3-dimethyl-1,3-butadiene (->19), and 1,3-butadiene (->21).With quadricyclane only the product (14) originating from a cycloaddition is formed, while with 2,5-norbornadiene the and cycloadducts (14 and 15) are formed.In addition the ene products (16, 18, 20, 22) are isolated in some cases from side reactions. - The tendency of 1 and 4 to preferably participate in cycloaddition reactions is ascribed to the polarity of the Si=C bond and the additional influence of the ? donor ligands at silicon.These factors enable a stepwise reaction in which the primary zwitterionic intermediates B are cyclized to yield the SiC fourmembered ring compounds. - Key Words: Silene, neopentyl-/ Me3SiO substituents/ Cycloaddition reactions/ Silaethene derivatives
