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Regioselective oxidative ring opening of cyclopropyl silyl ethers: a quantum chemical study.

Research paper by Heiko H Rinderhagen, Jochen J Mattay, Rafael R Nussbaum, Thomas T Bally

Indexed on: 12 May '10Published on: 12 May '10Published in: Chemistry - A European Journal



Abstract

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.