Sulfonyl esters. 2. CS cleavage in some substitution reactions of nitrobenzenesulfonates

Abstract

An attempt to explore aromatic sulfonate esters as agents for the condensation of alcohols with mercaptans revealed an unusual process for sulfonate esters: CS bond rupture. Two mechanistic possibilities for CS bond rupture are explored: (i) radical anion intermediacy via single electron transfer and (ii) nucleophilic aromatic substitution. Both experiments and molecular orbital computations are presented to support the conclusion that nucleophilic aromatic substitutions are occurring.Key words: sulfonyl esters, nitrobenzenesulfonates, CS bond rupture.

Sulfonyl esters 6. Elucidation of the first sequence in the Trithioorthoformate Reaction

“…l o Standard work-up furnished crude product (2.170 g), which was chrornatographed on silica gel (220 g) employing carbon tetrachloride elution (20 100-mL fractions) followed by chloroform elution (100-mL fractions). Fractions 25-27 were combined and concentrated, giving clean sulfide-sulfonate ester 2 (1.292 g, 3.93 mmol, 29%).…”

“…The selective displacement of ortho bromine atoms is entirely inconsistent with the formation of a Meisenheimer complex (3 (8).…”

“…3 A priori, the plethora of established oxidizing agents for the conversion of mercaptans to disulfides (6) makes it likely that the mercaptide anions would be oxidized in preference to the sulfonate-stabilized carbanions. In accord with that supposition, eq.…”

“…The nitrosulfonate ester (LUMO eigenvalue -1.9839 eV) undergoes nucleophilic aromatic substitution with mercaptide anions (3).…”

Structure‐function studies for in vitro chemical inhibition of Fcγ receptor–mediated phagocytosis

“…Nitrophenyl‐containing molecules may serve as redox reagents following a single‐electron transfer pathway. A detailed discussion of this possibility for some reactions of mercaptide anions with nitrophenyl‐containing molecules has been published 38 . A priori, it was possible that nitrophenyl‐containing molecules, which lack a sulfur functional group, might effectively inhibit phagocytosis.…”