Domino Reactions with Dicyanoalkenes and Fluorinated Conjugated Sulfinyl Imines. A Convenient Strategy for the Generation of Structural Diversity

Dicyanoalkenes are versatile reagents in organic synthesis and they have been extensively used in a wide variety of organic transformations. However, their reactivity towards fluorinated imines remained almost unnoticed. The divergent reactivity of fluorinated conjugated sulfinyl imines with dicyanoalkenes is described herein. On the one hand, when tert-butyl sulfinyl imines were employed, a cycloaromatization cascade process took place preferentially, rendering valuable trifluoromethyl arenes. On the other hand, the reaction with p-tolyl sulfinyl imines mainly led to a complex tetracyclic skeleton, involving an azetidinimine rearrangement of a reaction intermediate. Finally, when 1-indanone-derived dicyanoalkenes were employed, the aromatization process was interrupted, rendering a new family of diene derivatives. Theoretical calculations were performed in order to shed light on the mechanistic outcome of this transformation. image

Automated summary

This study reveals the different reactivity of fluorinated conjugated sulfinyl imines with dicyanoalkenes in organic synthesis. Specifically, tert-butyl sulfinyl imines undergo cycloaromatization reaction with dicyanoalkenes, leading to valuable trifluoromethyl arenes. p-tolyl sulfinyl imines, on the other hand, produce a complex tetracyclic skeleton. 1-indanone-derived dicyanoalkenes interrupt the aromatization process, resulting in a new family of diene derivatives.