A Stereodynamic Probe Providing a Chiroptical Response to Substrate-Controlled Induction of an Axially Chiral Arylacetylene Framework

A stereodynamic probe containing a central 1,4-di(phenylethynyl)benzene rod and two 2-formylphenylethynyl branches has been prepared through a series of Sonogashira cross-coupling reactions with 62% overall yield. This CD silent diarylacetylene-based framework carries two terminal aldehyde groups and provides a strong chiroptical response to substrate-controlled induction of three chiral axes upon diimine formation. The chiral amplification results in intense Cotton effects that can be used for in situ ICD analysis of the absolute configuration and ee of a wide range of amines.