Tin-free radical reactions under minimal solvent conditions for the synthesis of substituted chromones and coumarins

An alkyltin-free radical methodology carried out under minimal solvent conditions is presented. This free radical addition process allows for the preparation of a variety of substrates, including substituted chromones and coumarins. This method is high yielding, conducted at ambient temperature and, in nearly all instances, classical purification techniques such as chromatography are not needed.