Dichotomy of Reductive Addition of Amines to Cyclopropyl Ketones vs Pyrrolidine Synthesis
作者:Oleg I. Afanasyev、Alexey A. Tsygankov、Dmitry L. Usanov、Denis Chusov
DOI:10.1021/acs.orglett.6b02945
日期:2016.11.18
interesting catalytic dichotomy was discovered: switching between simple ligand-free catalysts leads to fundamentally different outcomes of reductive reaction between amines and α-carbonylcyclopropanes. Whereas a rhodium catalyst leads to the traditional reductive amination product, ruthenium catalysis enables a novel reaction of pyrrolidine synthesis via ring expansion. The protocols do not require an
An iridiumcatalyst enables the reductive amination of carbonylgroups with unprecedented substrate scope, selectivity, and activity using formic acid as the hydrogen source (see scheme). The catalyst system provides significant improvement over commonly used boron hydrides.