Fast microwave promoted palladium-catalyzed synthesis of phthalides from bromobenzyl alcohols utilizing DMF and MO(CO)6 as carbon monoxide sources

A fast method utilizing in situ generated CO for the synthesis of phthalides has been developed. DMF and MO(CO)(6) were applied as two alternative CO-sources in these microwave promoted carbonylation-lactone formation reactions. MO(CO)(6) was found to be the more generally applicable CO-source and provided phthalides as well as dihydroisocoumarin, dihydroisoindone, and phthalimide from the corresponding aryl bromide via an efficient CO insertion within a 1 h reaction time. (C) 2004 Elsevier Ltd. All rights reserved.