tele Nucleophilic Substitutions of Hydrogen in m‐(Trichloromethyl)nitrobenzenes with Cyano and Ester Carbanions

Abstract

Stabilized carbanions of malonates, 2‐phenylacetonitrile, or isopropyl 2‐phenylacetate add to m‐(trichloromethyl)nitrobenzene derivatives to form σH adducts that lose a chloride ion to give intermediate exo‐dichloromethylene nitrocyclohexadienes. These undergo re‐aromatization through 1,5‐hydrogen shift to yield tele substitution mono adducts. Depending on the stoichiometry of the nitroarene to the carbanion, further addition of the nucleophile to the tele mono adduct can yield a mixture of products that are either double or triple adducts. At low temperature, the σH adducts undergo direct 1,2‐addition in competition with chloride ion elimination/1,5‐hydrogen shift.

cine- and tele-Substitution reactions: review of work from 2002-2016

“…In their conclusions, the authors stated that chlorine atoms activated nitroarene to attack the nucleophiles protecting the same positions that they occupied. In cooperation with Varounis, 20 …”

Regiospecific 1,4-Michael Addition of Phenylacetonitrile to 1,5-Diarylpenta-2,4-Dien-1-Ones

“…However, reports of the use of phenylacetonitrile as a Michael donor are scarce. 4,5 In addition, dienones as Michael acceptors can provide carbonyl and alkenyl groups for target molecules. Reports using dienones in the Michael addition have mainly focused on the use of 1,4-dien-3-ones to conduct double Michael addition.…”