Structure-Based Kinetic Control in a Domino Process: A Powerful Tool Toward Molecular Diversity in Chromone Series

Two
successive original routes leading to two novel families of
polyheterocycles starting from the versatile chromone-based Michael
acceptors platform are reported herein. The major aspect of this work
is the selective access to these frameworks by changing the course
of the domino process involved in their formation. First, enaminochromanones
were selectively accessed under uncommon kinetic control. In this
study, we showed that the tuning of the selectivity toward the kinetic
product could be achieved by key structural modifications of the different
reaction partners involved in the domino process. Once selectivity
was efficiently controlled, enaminochromanones were ultimately transformed
into a more complex family of polyheterocycles containing the pyrrolo-oxazinone
framework. Here, the modulation of the domino sequence toward these
particularly scarce structures was enabled by a pivotal switch in
reactivity induced by aryl-λ3-iodanes.