a-Aryl-a-Heteroarylmalononitriles via Proton-Transfer Dual-Ionization Nucleophilic Aromatic Substitution

Herein we report the synthesis of a-aryl-a-heteroarylmalononitriles. Retrosynthetically, such molecules should be readily available from a-arylmalononitrile and haloheterocycles via nucleophilic aromatic substitution (SNAr). Yet, these molecular-and reaction-classes are nearly unknown. Herein, it is described that traditional SNAr, basic conditions to yield nucleophilic a-arylmalononitrile anions, will not yield the target products. Rather, and simply, the products can arise under mild, formally neutral conditions by proton-transfer dual-ionization (PTDI) nucleophilic aromatic substitution (SNAr). This study includes a background analysis of aaryl-a-heteroarylmalononitriles and PTDI-SNAr, discovery and optimization of efficient coupling conditions, a study of various physical organic parameters governing the transformation, scope of the reaction, and applications in synthesis through malononitrile functional group interconversion.