A General and Highly Selective Chelate-Controlled Intermolecular Oxidative Heck Reaction
journal contributionposted on 27.08.2008, 00:00 by Jared H. Delcamp, Alexandria P. Brucks, M. Christina White
A novel chelate-controlled intermolecular oxidative Heck reaction is reported that proceeds with a wide range of nonresonance stabilized α-olefin substrates and organoboron reagents to afford internal olefin products in good yields and outstanding regio- and E:Z stereoselectivities. Pd−H isomerization, common in many Heck reactions, is not observed under these mild, oxidative conditions. This is evidenced by outstanding E:Z selectivities (>20:1 in all cases examined), no erosion in optical purity for proximal stereogenic centers, and a tolerance for unprotected alcohols. Remarkably, a single metal/ligand combination, Pd/bis-sulfoxide complex 1, catalyzes this reaction over a broad range of coupling partners. Given the high selectivities and broad scope, we anticipate this intermolecular Heck reaction will find heightened use in complex molecule synthesis.