Selective Metalations of 1,4-Dithiins and Condensed Analogues Using TMP-Magnesium and -Zinc Bases

TMPMgCl center dot LiCl and TMPZnCl center dot LiCl allow facile magnesiation and zincation, respectively, of the 1,4-dithiin scaffold, producing polyfunctionalized 1,4-dithiins A subsequent metalation of these S-heterocycles can also be achieved with the same TMP bases, leading to 2,3-disubstituted-1,4-dithiins. The Mg- and Zn-TMP bases allow as well the successful metalation of 1,4,5,8-tetrathianaphthalene and 1,4,5,6,9,10-hexathiaanthracene.