Nickel-Catalyzed Regioselectivity-Switchable Hydroheteroarylation of Vinylarenes with Electron-Rich Heteroarenes.

We report the first example of a regioselectivity switch in the hydroheteroarylation of vinylarenes with electron-rich heteroarenes, including benzofurans, benzothiophenes, and indoles, using an expedient ligand-controlled strategy. In the presence of NaOtBu, Ni(IMesMe)[P(OEt)3]Br2 yields C2-alkylated heteroarenes with high branched selectivity, whereas the use of Ni(IPr*OMe)[P(OEt)3]Br2 favors the formation of the corresponding linear products. This robust method also provides easy access to a range of C2-alkylated electron-rich heteroarenes without employing directing groups.

Ligand-Controlled Nickel-Catalyzed Tandem Isomerization/Regiodivergent Hydroheteroarylation of α-Alkenes with Heteroarenes.

We herein describe an accessible ligand-controlled nickel-catalyzed tandem isomerization/regiodivergent hydroheteroarylation of α-alkenes with a series of heteroarenes, wherein the NHC ligand of heteroleptic Ni(II) complexes of the type Ni(NHC)[P(OEt)3]Br2 displayed significant effects on regulation. In the presence of NaOtBu, Ni(IMes)[P(OEt)3]Br2 enables C═C bond isomerization of α-alkenes over up to four sp3 carbon atoms to afford branched products, while Ni(IPr*OMe)[P(OEt)3]Br2 greatly deactivates α-alkene isomerization and favors the formation of linear products.