Catalytic Direct C2-Alkenylation of Oxazoles at Parts per Million Levels of Palladium/PhMezole-Phos Complex

Org Lett. 2016 Oct 21;18(20):5300-5303. doi: 10.1021/acs.orglett.6b02619. Epub 2016 Oct 11.

Abstract

General direct C2-alkenylation of oxazoles is reported using alkenyl tosylates at parts per million levels of palladium catalyst. From a series of ligands screened, PhMezole-Phos emerged as the promising ligand candidate to facilitate this reaction. Significantly, the method is scalable and exhibits excellent substrate tolerance. Highly sterically hindered substrates and small vinyl tosylate can be coupled successfully. Moreover, our method enables a rapid diversification of oxazole-based C^N ligands which can be readily derived into new group 9 organometallic compounds.