Substituent effects in the insertion of cyclopropylidenes into 3,4-related C–H-bonds

Abstract

The carbenes (4, R = aryl)(or related carbenoids) undergo competitive rearrangement to allenes (2) and insertion into a C–H bond 3,4-related to the carbene centre to produce (3); the product ratio can be correlated with substituent σ-constants, leading to a ρ-value of –0·50 ± 0·01 for the insertion.