Transformation of 4-Nitrobenzyl Halides at the Action of Phosphinates and Carboxylic Acids Orthoesters

摘要

Previously we studied the reaction of organic gem-di- and trihalides with methyl esters of P(IV) acids and trialkyl orthoformates. However, the literature contains no information on the reaction of the above reagents with organic monohalides. We first discovered that methyl diethylphosphinate II reacts with halides Ia and Ib at 150 and 180°C, respectively, to form 4-nitrobenzyl diethylphosphinate IV. Apparently, the phosphinate II attacks the methylene carbon of halide I by its more nucleophilic phosphoryl oxygen. The resulting quasiphosphonium salt III can be stabilized via the second stage of the Arbuzov reaction to release methyl halide V and to form a stable phosphinate IV.