Enantioselective Sensing of Amines Based on [1 + 1]-, [2 + 2]-, and [1 + 2]-Condensation with Fluxional Arylacetylene-Derived Dialdehydes

Four induced circular dichroism (ICD) probes exhibiting a stereodynamic arylacetylene framework and terminal aldehyde units have been prepared. The CD silent sensors generate a strong chiroptical response to substrate-controlled induction of axial chirality upon selective [1 + 1]-, [2 + 2]-, and [1 + 2]-condensation. The intense Cotton effects can be exploited for in situ ICD analysis of the absolute configuration and ee of a wide range of amines.