Integrating Catalysis and Analysis: Accelerated Asymmetric Reaction Development With a Multitasking Reactivity Umpolung/Chiroptical Reporter Auxiliary.

High-throughput asymmetric reaction development of an organocatalytic Michael addition is achieved by using a readily available isatin molecule as an amine protecting group, reagent for reactivity Umpolung, and as a chiroptical yield and enantioselectivity reporter. The use of UV and circular dichroism inductions allows on-the-fly, chromatography-free parallel screening of a hundred reaction conditions to identify a catalytic procedure that converts a primary amine to either enantiomer of an a-branched chiral product in excellent yields and ee's. The isatin is recyclable and can be quantitatively recovered if desired. This case study shows how chiroptical high-throughput screening with a multitasking reagent can increase method development speed and reduce cost and waste compared to traditional reaction optimization workflows by streamlining the analysis of small-scale reaction setups and eliminating time-consuming work-up protocols.