Catalytic Direct C2-Alkenylation of Oxazoles at Parts per Million Levels of Palladium/PhMezole-Phos Complex
作者:Wai Chung Fu、Yong Wu、Chau Ming So、Shun Man Wong、Aiwen Lei、Fuk Yee Kwong
DOI:10.1021/acs.orglett.6b02619
日期:2016.10.21
ligand candidate to facilitate this reaction. Significantly, the method is scalable and exhibits excellent substrate tolerance. Highlystericallyhindered 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.
Nickel promoted switchable hydroheteroarylation of cyclodienes via C–H bond activation of heteroarenes
作者:Wei-Chih Lee、Wei-Chin Shih、Ting-Hsuan Wang、Yuhua Liu、Glenn P.A. Yap、Tiow-Gan Ong
DOI:10.1016/j.tet.2015.03.066
日期:2015.7
hydroheteroarylation of cyclicdienes via C–H bond activation of heteroarenes. In the presence of an N-heterocyclic carbene (NHC) ligand, hydroheteroarylation of cyclicdiene with azole afforded α-alkenyl-azole, forging a Heck-like product without using any external oxidant. Conversely, changing the ligand to PCy3 would switch this reaction manifold to afford the other isomeric β-alkenyl substituted azole.
A catalytic system comprised of Pd(OAc)2 and bidentate ligand dppe enabled first direct arylations with moisture-stable aryl sulfamates as electrophiles, and proved applicable to unprecedented C−H bond functionalizations with easily accessible alkenyl phosphates as well as benzyl phosphates.