ChemInform Abstract: ANIONIC (3 + 2)‐CYCLOADDITION OF DITHIOBENZOATE ANION WITH ACTIVATED MULTIPLE BONDS

Abstract

Das Dithiobenzoat‐Anion in Form des Salzes (I) reagiert mit den aktivierten Alkinen (II) bzw. (IV) in einer 3 + 2‐Cycloadditionsreaktion zu den 1,3‐Dithiolen (III) bzw. (V).

The Addition Reactions of Pyrrolecarbodithioates to Activated Alkenes and Alkynes

“…1 The reactions of the 1,3-anionic cycloaddition are typical on condition that the central Catom of -R-CS 2¯ has aromatic or heteroaromatic substituents R supporting the anion stabilization. 9,10 Thus, the salts of pyrrole-1-, thiophene-2-, furane-2-, and naphthalene-1-dithiocarboxylic acids selectively react with the dimethyl ester of acetylenedicarboxylic acid to form cycloadducts. 9 We found that the reaction of potassium pyrrole-1-carbodithioate (1) with the ethyl ester of propiolic acid (7a) and with benzoylacetylene (7b) in DMSO (room temperature, 2 hours) leads to normal adducts; the S-ethenylpyrrole-1-carbodithioates 8a, 8b in 10% and 18% yield, respectively.…”