Efficient Synthesis of Sterically Hindered Arenes Bearing Acyclic Secondary Alkyl Groups by Suzuki–Miyaura Cross‐Couplings

Abstract Bulky P,PO ligands were designed to inhibit isomerization and reduction side reactions during the cross coupling between sterically hindered aryl halides and alkylboronic acids. Suzuki–Miyaura cross‐couplings between di‐ ortho ‐substituted aryl bromides and acyclic secondary alkylboronic acids have been achieved with high yields. The method has also enabled the preparation of ortho ‐alkoxy di‐ ortho ‐substituted arenes bearing isopropyl groups in excellent yields. The utility of the synthetic method has been demonstrated in a late‐stage modification of estrone and in the application to a new synthetic route toward gossypol.