Abstract
We conducted detailed studies on CO-assisted reductive chemistry with cyclopropyl
ketones as a special type of substrate. Multiple factors influencing the outcome of
the reaction have been studied for both ruthenium and rhodium catalysis. An unusual
rearrangement of aminomethylcyclopropanes was found. We showed that some reductive
reactions, which were believed to proceed through a water–gas shift reaction pathway,
can nonetheless take place even without an external or internal water source, indicating
a more interesting reaction mechanism. Cyclopropylketones were employed as bifunctional
electrophiles and, depending on the conditions, the reaction with an amine can lead
to a number of products, including aminoketones, cyclopropyl methylamines, pyrrolidines
or 1,4-diaminopentanes.
Key words
donor–acceptor cyclopropane - pyrrolidines - carbon monoxide - reductive amination
- water–gas shift reaction - cyclopropyl amines rearrangement - ring opening