149439-17-8Relevant articles and documents
Silaheterocycles, XXIV. E-Configurated 1-Amino-2-neopentylsilenes: Synthesis and Cycloaddition Reactions
Auner, Norbert,Weingartner, Armin W.,Herdtweck, Eberhardt
, p. 318 - 332 (2007/10/02)
The 1-amino-2-neopentylsilenes 5-8 are formed in the reaction of LitBu with the aminovinylsilanes 1-4 in n-pentane (addition of LitBu to the vinylic double bond with subsequent 1,2-elimination of LiCl).The α-Li adducts initially formed are trapped by Me3SiOSO2CF3 to yield α-SiMe3-silanes.The silenes undergo insertion reactions into the Si-O bond of Me3SiOMe.In the absence of any trapping reagent dimerization occurs.One of the 1,3-disilacyclobutanes thus formed (15) could be examined by X-ray diffraction.Reacting with 1,3-butadienes the chlorosubstituted silene s 5 and 8 yield -cycloaddition products.With 1,3-cyclohexadiene Diels-Alder adducts are also obtained, but with cyclopentadiene the adducts are formed exclusively.Products of an ene-reaction are observed upon treatment of 2,5-norbornadiene with the silenes 5 and 8. The methylsubstituted silene 6 does not undergo any cycloaddition reaction at all, while from silene 7 only traces of the cycloadducts are produced.Both species mainly yield the dimers.The preference for the reaction type, exhibited by the silenes 5 and 8, is due to their polarity.The almost complete absence or low yield of any cycloaddition products from 6 or 7 can be correlated with the energy levels of their frontier molecular orbitals.The distribution of the disilacyclobutanes and cycloaddition product isomers is explained by the characteristics of the stereospecifically E-configurated silenes.The product distribution can also be rationalized considering the ambiphilic nature of the system ViRR'SiCl/LitBu. Key Words: Silaheterocycles, Synthesis, Aminochlorovinylsilanes, Formation of Silenes, Cycloaddition Reactions
