Convenient Access to 2,3-Disubstituted-cyclobut-2-en-1-ones under Suzuki Conditions and Their Synthetic Utility.

A regioselective synthesis of general applicability has been designed for the one-pot preparation of 2,3-disubstituted-cyclobutenones from iodoalkynes through cyclobutenylation, Suzuki CC coupling, and ketone formation. This one-pot methodology has been applied to the selective synthesis of an orally active cyclooxygenase II inhibitor. Furthermore, the obtained cyclobut-2-en-1-ones were used as synthons in several transformations, such as, the preparation of β-lactams, phthalazines, cyclohexa-2,5-dien-1-ones, and cyclopent-3-en-1-ones.