Summary: FULL PAPER
On the Question of Cyclopropylidene Intermediates in Cyclopropene-to-Allene
Rearrangements Tetrakis(trimethylsilyl)cyclopropene, 3-Alkenyl-1,2,3-
tris(trimethylsilyl)cyclopropenes, and Related Model Compounds
Armin de Meijere,*[a]
and Yitzhak Apeloig*[d]
Dedicated to Professor Jürgen Troe on the occasion of his 60th birthday
Keywords: Cyclopropenes / Reactive intermediates / Carbenes / Unimolecular reactions / Silyl group effects / Quantum
Several tetrasubstituted cyclopropenes have been prepared
and their pyrolyses and photolyses have been investigated.
Tetrakis(trimethylsilyl)cyclopropene (10), which was ob-
tained in 25% yield from tris(trimethylsilyl)cyclopropenylium
hexachloroantimonate (9), gave tetrakis(trimethylsilyl)allene
(12) as the sole product both thermally and photochemically.
Kinetic studies in [D8]toluene indicated first-order behavior