Nitronaphthalene derivatives react as Michael acceptors in the Corey–Chaykovsky reaction with alkyl phenyl selenones and alkyl diphenyl sulfonium salts. Mechanistic studies reveal that sterically demanding substituents at the carbanionic center favor formation of cyclopropanes and suppress competitive β-elimination to the alkylated products. The transformation, demonstrated also on heterocyclic nitroquinoline and nitroindazolines, is an example of transition metal-free dearomatization method.

Electrophilic nitropyridines react with sulfonyl-stabilized carbanions to give products of C–H alkylation via vicarious nucleophilic substitution. The process consists of formation of the Meisenheimer-type adduct followed by base-induced β-elimination of the sulfinic acid (e.g., PhSO 2 H). Mechanistic studies reveal that in the latter step alkyl substituent and adjacent nitro group tend to planarize for effective stabilization of benzyl anion, and thus, adduct of hindered isopropyl carbanion remains stable toward elimination for steric reasons.

Studies on directed ortho-metalation (DoM) of arenesulfonyl fluorides (ArSO2F) with in situ electrophile trapping are presented. Under optimized conditions (LDA, THF, –78 °C), a series of model substrates was mono- and difunctionalized with trimethylsilyl chloride in good yields. The synthetic results reveal powerful directing character of the SO2F group, being ahead of bromine and methoxy substituents. Under the same metalation conditions, aryl fluorosulfates (ArOSO2F) display fragmentation to arynes and migration of the SO2F group to the ortho position (anionic thia-Fries rearrangement).

Alkylation of nitroarenes via Vicarious Nucleophilic Substitution (VNS) was tested experimentally and modelled with DFT calculations. Mechanistic studies reveal intrinsic differences between reactions of archetypal carbanion precursor PhSO2CH2Cl, and alkyl phenyl sulfones, in which benzenesulfinate acts as a leaving group. Accordingly, for the latter precursors steric hindrance develops at the β‐elimination step, that raises energy barrier and results in the formation of byproducts.

Ammonia. -The scope of the title reaction may be limited by the formation of the corresponding carboxylic acid as a side product. -(ANTONIAK, D.; SAKOWICZ, A.; LOSKA, R.; MAKOSZA*, M.; Synlett 26 (2015) 1, 84-86, http://dx.