Regioselective oxidative ring opening of cyclopropyl silyl ethers: a quantum chemical study.
In contrast to the structurally and configurationally stable alkyl- or aryl-substituted cyclopropyl radical cations, cyclopropyl silyl ethers undergo spontaneous ring opening upon oxidation whereby the endocyclic C-C(O-TMS) bond is cleaved with remarkable selectivity. DFT calculations on 1-trimethylsilyloxybicyclo[4.1.0]heptane show that this selectivity arises from the topology of the potential surface of the corresponding radical cation which is initially generated in a very steep region of the potential surface from where the steepest descent leads to cleavage of the endocyclic rather than the lateral C-C(OTMS) bond. Cleavage of the lateral bond leads to interesting conformational changes which are explored in detail.
Rinderhagen
Heiko
H
Department of Chemistry, Bielefeld University, P.O. Box 100131, 33501 Bielefeld, Germany.
Mattay
Jochen
J
Nussbaum
Rafael
R
Bally
Thomas
T