Nickel-Catalyzed Mizoroki–Heck/Amination Cascade Reactions of <i>o</i>-Dihaloarenes with Allylamines: Synthesis of Indoles
作者:Xu Chen、Jin Lin、Biao Wang、Xu Tian
DOI:10.1021/acs.orglett.0c02909
日期:2020.10.2
An efficient Mizoroki–Heck/amination cascade reaction of o-dihaloarenes with allylamines has been developed using nickel and IPr carbene ligand as catalyst. This protocol enables the synthesis of a broad range of substituted indoles by a cascade process, from readily available starting materials. Mechanistic studies suggest that the Mizoroki–Heck reaction occurred first under IPr-nickel catalysis.
Various atropisomeric amides were prepared in optically pure forms (≥98% ee) through the opticalresolution of the amide ester derived from (R)-pantolactone, N-allyl-ortho-tert-butylaniline and oxalyl chloride. Asymmetric carbonyl addition reaction of an alkyllithium and asymmetric iodolactonization with these atropisomeric amides proceeded with high stereoselectivity.
new axially chiral N-acryl-N-allyl-o-tert-butylanilide wih high optical purity (96–97 %ee) was prepared in good yield from (S)-O-acetyl lactic acid and N-allyl o-t-butylaniline. Iodinemediated Diels-Alderreaction of the axially chiral N-acryl anilide with cyclopentadiene or isoprene proceeded with high diastereoselectivity.