Convenient synthesis of photochromic symmetrical or unsymmetrical bis(heteroaryl)maleimides via the Suzuki–Miyaura cross-coupling reaction

A general method for the synthesis of symmetrical or unsymmetrical bis(heteroaryl)maleimides by a one-pot procedure involving Suzuki–Miyaura cross-coupling sequence was developed on the basis of the reaction of 3,4-diiodo-1-benzyl-1H-pyrrole-2,5-dione with cyclic boronate esters using PdCl2(dppf) as the catalyst. Photochromic properties of the products were examined.