Palladium‐Catalyzed Ring‐Opening Addition of Activated Vinyl Cyclopropanes with N‐Tosylhydrazones

Abstract

Ring‐opening addition reaction of activated vinyl cyclopropanes with N‐tosylhydrazones in the presence of palladium(0) and triphenylphosphine affords N‐tosylhydrazone butenylmalonate compounds. Aromatic aldehyde‐derived N‐tosylhydrazones produced terminal and internal N‐allylated products, in which the terminal products are the main. While ketone‐derived tosylhydrazones produced only terminal addition products. The transformation relationship of the terminal and internal N‐allylated products in the reaction was also observed. A reasonable mechanism is proposed based on preliminary experimental results.

Palladium-catalyzed site-selective functionalization of unactivated alkenes with vinylcyclopropanes aided by weakly coordinating native amides

“…Coordination of vinylcyclopropane 2a with intermediate G followed by oxidative addition gives intermediate H which will be in equilibrium with sterically favorable terminal η 1 palladium intermediate I . 9 Finally, intermediate I undergoes reductive elimination to complete the catalytic cycle with the release of the desired product.…”