Open AccessPhotoinduced Brook-Type Rearrangement of Acylcyclopolysilanes
Author(s) -
Harald Stueger,
Bernd Hasken,
Michael Haas,
Martin Rausch,
Roland C. Fischer,
Ana Torvisco
Publication year - 2013
Publication title -
organometallics
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.231
H-Index - 172
eISSN - 1520-6041
pISSN - 0276-7333
DOI - 10.1021/om4009845
Subject(s) - chemistry , trimethylsilyl , adduct , ring (chemistry) , methanol , crystallography , nuclear magnetic resonance spectroscopy , double bond , potassium , spectroscopy , stereochemistry , photochemistry , medicinal chemistry , polymer chemistry , organic chemistry , physics , quantum mechanics
Previously unknown 1,1,4-tris(trimethylsilyl)-4-acyldodecamethylcyclohexasilanes (Me 3 Si) 2 Si 6 Me 12 (Me 3 Si)COR ( 16a , R = tert -butyl; 16b , R = 1-adamantyl) have been synthesized by the reaction of the potassium silanides (Me 3 Si) 2 Si 6 Me 12 (Me 3 Si)K with acid chlorides ClCOR, and their photochemical rearrangement reactions have been studied. The molecular structures of 16a , b as determined by single-crystal X-ray diffraction analysis exhibit an unusual twist-boat conformation of the cyclohexasilane ring. When 16a , b were photolyzed with λ >300 nm radiation, they underwent Brook type 1,3-Si → O migration reactions to generate the cyclohexasilanes 17a , b with exocyclic Si=C bonds along with smaller amounts of the ring-enlarged species 19a , b with endocyclic Si=C double bonds. While 17a , b were stable enough to allow characterization by NMR and UV absorption spectroscopy, the less stable products 19a , b could only be observed in the form of their methanol adducts.