Palladium-Catalyzed β-Arylation of α-Keto Esters

Heck Reaction of 2-Oxyacrylates with Aryl Bromides: A Common Route to Monoaryl Pyruvates and Ortho Ester-Protected Monoaryl Pyruvates

A palladium-catalyzed Heck reaction between 2-oxyacrylates and aryl bromides was developed, where DavePhos was a unique ligand that efficiently promoted the reaction. The products, 2-oxycinnamates, served as excellent precursors, providing synthetically useful monoaryl pyruvates or ortho ester-protected monoaryl pyruvates depending on the nature of the 2-oxy group. The formation of such ortho esters via alkoxide addition is novel, and computational studies identified a plausible mechanism with an oxyallyl zwitterion as the key intermediate.

Development of an enolate alkynylation approach towards the synthesis of the taiwanschirin natural products

Through the use of model studies, an approach was conceived towards the synthesis of the taiwanschirin family of natural products. These are structurally complex compounds which represent highly challenging and biologically active targets for total synthesis. This work describes a successful synthesis of the complex taiwanschirin fused [8,6,5] core through a novel alkynylation reaction coupled with an intramolecular Heck reaction used to construct the 8-membered ring.

Formation of Complex α-Imino Esters via Multihetero-Cope Rearrangement of α-Keto Ester Derived Nitrones

A sequential benzoylation and multihetero-Cope rearrangement of α-keto ester derived nitrones has been developed. The reaction furnishes a diverse array of complex α-imino ester derivatives. The products can be transformed into amino alcohols via LiAlH₄ reduction.