A palladium-catalyzed methylenation of olefins using halomethylboronate reagents.
Methylenation of electron-rich olefins is a highly challenging reaction, for which we have developed a new methodology exploiting Pd-catalysis and halomethylboronate reagents, the latter replacing diazomethane and zinc carbenoids as methylene donors. Optimization of the reaction for norbornene and extension to several other olefins are reported, with reasonable-to-excellent yields of cyclopropanes in combination with β-H elimination products. Several mechanisms are plausible for this methylenation reaction.
Laboratorium für Organische Chemie, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zürich, Switzerland.
Tim
T
den Hartog
Juan Manuel Sarria
JM
Toro
Peter
P
Chen