Cyclopropanes through C–H activation

Abstract

Organic Chemistry Despite the strain inherent in triangular carbon rings, these cyclopropane motifs are surprisingly common in natural products and pharmaceuticals. Their synthesis often involves the addition of highly reactive carbenes to C=C double bonds. Clemenceau et al. now report an alternative route whereby a palladium catalyst and base pluck hydrogens off of alkyl groups straddling a benzylic center, which then join together to form the third edge of the triangle. The reaction is highly sensitive to the nature of the base, with pivalate yielding the desired product and carbonate leading to a competing cyclobutene motif. J. Am. Chem. Soc. 142 , 15355 (2020).