Organocatalytic Enantioselective Vinylcyclopropane‐Cyclopentene (VCP‐CP) Rearrangement
Gorka Garay, Josebe Hurtado, Manuel Pedrón, Lorena García, Efraím Reyes, Eduardo Sánchez‐Díez, Tomás Tejero, Luisa Carrillo, Pedro Merino, José L. Vicário
Abstract
We have demonstrated that the catalytic and enantioselective vinylcyclopropane-cyclopentene rearrangement can be carried out on (vinylcyclopropyl)acetaldehydes through activation via enamine intermediates. The reaction makes use of racemic starting materials that, upon ring opening facilitated by the catalytic generation of a donor-acceptor cyclopropane, deliver an acyclic iminium ion/dienolate intermediate in which all stereochemical information has been deleted. The final cyclization step forms the rearrangement product, showing that chirality transfer from the catalyst to the final compound is highly effective and leads to the stereocontrolled formation of a variety of structurally different cyclopentenes.