Synthesis and structure of new vinylcoppersiloxanes and stereoregular organocyclosilsesquioxanes based on them†
Abstract
This paper presents an approach for the directed synthesis of new vinylcoppersiloxanes with 10-membered and bicyclic siloxanolate ligands from vinylcoppersodiumsiloxane with a globular structure in the presence of 2.2′-bipyridine. The primary factor influencing the formation of a specific complex was the ratio of vinylcoppersodiumsiloxane to 2,2′-bipyridine. The composition and structure of the resulting complexes were confirmed by elemental analysis and single crystal X-ray diffraction. Trimethylsiloxy-, vinyldimethylsiloxy-, and dimethylsiloxy-derivatives of stereoregular vinylsiloxanes with cis-bicyclic and cis-pentameric configurations, hitherto undescribed in the literature, were successfully synthesized using the obtained vinylcoppersiloxanes. Additionally, the possibility of generating amphiphilic Janus structures was demonstrated through hydrothiolation of the obtained vinylcyclosiloxanes with mercaptoacetic acid. The purity and structures of all cyclic compounds were confirmed by a complex of physico-chemical analytical techniques, including 1H, 13C and 29Si NMR, IR spectroscopy, mass spectrometry, GPC and elemental analysis.