yielding steps by combining the Ugi or Passerini multicomponent reactions with two metal‐catalyzed cyclizations: an intramolecular Tsuji–Trost reaction of the isocyanide‐derived amide followed by a ring‐closing metathesis. Scaffold diversity may be explored by the appropriate choice of starting unsaturated isocyanides. The Tsuji–Trost cyclization proceeds with moderate to good diastereoselectivity, and the
erythritol derivative, was further functionalized and then submitted to stereoselective Passerini reactions, allowing the synthesis of a small library of new molecules. Thanks to the presence of different functional groups, further cyclizations were performed providing bicyclic polyoxygenated heterocycles.
The first example of a dearomative palladium-catalysed isocyanide insertion reaction has been developed using functionalized isocyanides as the reaction partner of N-(2-bromobenzoyl)indoles. The imidoyl-palladium intermediate generated by tandem indole double bond/isocyanide insertion reactions could be trapped by intramolecular functional groups such as the C(sp2)-H bond and alkenes, affording diversified
Stereoselective Construction of Unsymmetrically Linked Heterocycles via Palladium-Catalyzed Alkyne Insertion/Cycloimidoylation Cascade
作者:Haixia Zhao、Shumin Ding、Dan Li、Minxue Chai、Lixiong Dai、Jing Li、Yuchen Jiang、Tongqing Weng、Jian Wang
DOI:10.1021/acs.joc.2c02660
日期:2023.2.3
strategy to access unsymmetrically linked heterocyclesviapalladium-catalyzed acylcycloimidoylation of alkyne-tethered carbamoyl chlorides with isocyanides has been developed. Functionalized isocyanides were successfully applied as imine-containing heterocycle precursors to capture the vinyl-PdII intermediate, which was generated from a syn-carbopalladation of alkyne, followed by subsequent intramolecular
Enantioenriched 2-azabicyclo[3.1.0]hexanes are accessed from readily available allyl substituted α-isocyanoesters by intramolecular (1 + 2) cycloaddition with the olefinic moiety and isocyano carbon as the respective C2 and C1 units. Cyclopropanation is initiated by 1,1-hydrocupration of isocyanide followed by formimidoylcopper to copper α-aminocarbenoid equilibration and subsequent (1 + 2) cycloaddition