Silaheterocyclen. VI. Erzeugung und -Cycloadditionsreaktionen von 1-Vinyl-1-chlor-2-neopentylsilaethen

Article abstract of DOI:10.1016/0022-328X(89)80079-8

Vi2SiCl2 (3) reacts with LiBu^t to give 1-vinyl-1-chloro-2-neopentylsilaethene (2), which in the absence of suitable partners cyclodimerizes to 1,3-divinyl-1,3-dichloro-2,4-dineopentyl-1,3-disilacyclobutane (6).With C5H6, C5Me5H or anthracene 2 is trapped by formation of the <2+4> cycloadducts, which in a similar reaction with LiBu^t yield the "norbornene-, pentamethylnorbornene"- and"dibenzo-2-silabicyclooctanesilaethenes" (30, 35 and 36) respectively.These undergo reactions with dienes affording <2+2> and/or <2+4> cycloadducts.The observed products and their distribution are best explained by assuming the silaethenes 30, 35 and 36, respectively together with their α-lithio precursors as reactive intermediates.Probably because of steric hindrance 30 and 36 do not dimerize to 1,3-disilacyclobutane derivatives.