Stabilizing Highly Reactive Aryl Carbanions in Water Microdroplets: Electrophilic Ipso-Substitution at the Air–Water Interface

The fleeting existence of aryl carbanion intermediates in the bulk phase prevents their direct observation and spectroscopic measurement. In sharp contrast, we report the direct interception of such unstable species at the air-water interface of microdroplets. We observed the transformation of three types of aryl acids (benzoic, phenylsulfinic, and phenylboronic acids) into phenyl carbanion (Ph