Unwringing the ring: Methylenecyclopropanes reacted with vinyl and aryl Grignard reagents in the presence of a nickel catalyst to afford vinyl‐ and arylmagnesation products, respectively, through a selective CC bondcleavage (see scheme). The reaction provides a new method for the preparation of substituted homoallyl and allyl Grignard reagents.
Mechanistic and exploratory organic photochemistry. LXXXVII. Photochemical rearrangement of 4-aryl-substituted cyclopentenones. Low-temperature photochemistry and direct observation of reaction intermediates