Intramolecular O-arylation of phenols with phenylboronic acids: application to the synthesis of macrocyclic metalloproteinase inhibitors.

[reaction: see text]. The copper acetate mediated intramolecular O-arylation of phenols with phenylboronic acid pseudopeptides is the key step in the preparation of macrocyclic biphenyl ether hydroxamic acid inhibitors of collagenase 1 and gelatinases A and B. The intramolecular macrocyclization was found to be mild and tolerant of common chemical functionality. This methodology should provide a general route to macrocyclic biphenyl ethers.