Synthesis of 1- and 2-substituted thianthrenes

Abstract

Lithiation of thianthrene at C-1 allows the synthesis of various 1-substituted thianthrenes for example thianthren-1-ylboronic acid and 1-tributylstannylthianthrene, which undergo palladium-catalysed couplings with aryl halides. 2-Bromothianthrene provides an entry to 2-substituted thianthrenes via lithium–halogen exchange then reaction of 2-lithiothianthrene with electrophiles including formation of the 2-boronic acid and 2-tributylstannylthianthrene which were coupled to aryl halides.