Ishikawa S, Hudson R, Masnadi M, Bateman M, Castonguay A, Braidy N, Moores A, * Li
C.-J. * McGill University, Montreal and Université de Sherbrooke, Canada
Cyclopropanation of Diazoesters with Styrene Derivatives Catalyzed by Magnetically
Recoverable Copper-Plated Iron Nanoparticles.
Tetrahedron 2014;
70: 8952-8958
Key words
iron nanoparticles - cyclopropanation - diazoesters - alkenes - copper
Significance
Copper-plated iron nanoparticles (Cu@FeNPs) catalyzed the cyclopropanation of alkenes
with diazoesters to give the corresponding substituted cyclopropanes in up to 76%
yield (16 examples). In the reaction of 4-vinylanisole with benzyl diazoacetate, the
catalyst was recovered by magnetic separation and reused four times without significant
loss of catalytic activity.
Comment
The authors reported previously the preparation of Cu@FeNPs and its application to
the Huisgen reaction (Green Chem.
2012, 14, 622). ICP analysis revealed that 12 ppm of copper leached out from the fresh catalyst
during the reaction. The leached copper species showed no catalytic activity.
