Ligand-controlled NiH-catalyzed regiodivergent hydroalkylation of 2-alkenylazaarenes

A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor ligands.This method enables the synthesis of diverseβ-orγ-branched aromatic N-heterocycles.The mild regiodivergent protocols exhibit wide substrate scope,excellent functional tolerance,and great reaction yield with remarkable regioselectivity.Importantly,deuterium labeling studies reveal Ni H-catalyzed interrupted chain-walking mode as the mechanism behind remotedβ-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.

Ni-catalyzed regiodivergent hydrophosphorylation of enynes

A regiodivergent hydrophosphorylation of enynes with phosphites has been developed using earthabundant nickel catalyst.The manipulation of regioselectivity can be achieved by regulating the insertion order of alkyne bonds with(RO)_(2)P(O)-Ni-H or R_(2)P(O)O-Ni-H species,respectively.Under the Ni/Xantphos catalysis,4,1-hydrophosphorylation is selectively obtained while the adding of acid can promote reactions towards 1,2-addition.By employing an additional Pd-H catalysis,2,1-hydrophosphorylation is also an accessible task in one-pot reaction.Mechanistic studies and analysis have also been performed to interpret the origin of the regioselective regulation.This work highlights the arts in accessing different regioisomers by diverting common elementary reaction steps.

Ligand controlled cobalt catalyzed regiodivergent 1,2-hydroboration of 1,3-dienes

Regiodivergent 1,2-hydroboration of 1,3-dienes with pinacolborane has been accomplished by well-defined cobalt complexes of different bidentate ligands. The iminopyridine-cobalt system is selective for Markovnikov 1,2-hydroboration to form allylboronates, while the FOXAP-cobalt(FOXAP=(S)-1-(diphenylphosphino)-2-[(S)-4-isopropyloxazolin-2-yl]ferrocene) catalyst effects the complementary anti-Markonikv 1,2-hydroboration to afford homoallyboronates with high regioselectivity.

Nickel-Catalyzed Regiodivergent Asymmetric Cycloadditions of α,β-Unsaturated Carbonyl Compounds

Regiodivergent asymmetric cycloadditions from the same set of starting materials offer interesting opportunities for rapid construction of optically active cyclic molecules with structural diversity.However,this remains a challenging task due to the difficulty of simultaneously controlling the regio-,diastereo-,and enantioselectivity in the ring formation processes.To address this long-standing problem.

Asymmetric NiH-Catalyzed Regioselective Hydroalkynylation of Unactivated Alkenes

Herein,we disclose a ligand-controlled,directing group-assisted strategy to facilitate NiH-catalyzed hydroalkynylation of allyl amides at remoteα-position adjacent to nitrogen and initial olefinic site in a predictable and switchable manner.Bromoalkynedependent regiodivergent hydroalkynylation and asymmetric hydroalkynylation with a wide alkyne scope were achieved,producingα-and(enantioenriched)β-branched alkynyl-functionalized amine derivatives from the same raw materials.The formation of a carbonyl-ligated 5-or 6-membered nickelacycle intermediate via Ni migration or nonmigration was believed to be the key step in controlling the regioselectivity.This asymmetric protocol could be applied to synthesizing other value-added chiral aliphatic amines.