Photogenerated donor-donor diazo compounds enable facile access to spirocyclopropanes
Vincent George1, Burkhard König1
1Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg 93040, Germany. burkhard.koenig@chemie.uni-regensburg.de.
Abstract:
Prompted by the increasing interest in strained hydrocarbons as potential drug candidates, we developed a simple and efficient photochemical protocol for (spiro)cyclopropanes from bench stable tosylhydrazones and electron poor olefins. This two-step one-pot transformation proceeds by (3+2)-cycloaddition of in situ formed donor-donor diazo compounds, followed by nitrogen extrusion of the Δ1-pyrazoline intermediates. Notably, kinetic analysis enabled the isolation of intermediary spiro-heterocycles.
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