Tandem Synthesis of Pyrroloacridones via [3 + 2] Alkyne Annulation/Ring-Opening with Concomitant Intramolecular Aldol Condensation
摘要:
An efficient cascade strategy for the direct synthesis of pyrrolo[3,2,1-de]acridones 4a-v, 5a-h from iodopyranoquinolines 2a-i by the palladium-catalyzed regioselective [3 + 2] alkyne annulation/ring-opening followed by intramolecular aldol condensation under microwave irradiation is described. The chemistry involves the in situ formation of pyrroloquinolines Y, via palladium-catalyzed selective [3 + 2] annulation of iodopyranoquinolines and internal akynes with ring-opening and successive intramolecular cross-aldol condensation. Both the symmetrical and unsymmetrical internal alkynes were reacted smoothly to provide the desired pyrroloacridones in good yields. This methodology provides the facile conversion of easily accessble iodopyranoquinoline into highly functionalized biologically important pyrroloacridones in a single process.
Triple‐Bond Directed Csp
<sup>2</sup>
−N Bond Formation with
<i>N</i>
‐Fluorobenzenesulfonimide as Aminating Source: One‐Step Transformation of Aldehydes into Amines
作者:Sushmita、Trapti Aggarwal、Norio Shibata、Akhilesh K. Verma
DOI:10.1002/chem.201903495
日期:2019.12.13
amination of ortho‐alkynyl quinoline/pyridine aldehydes using N‐fluorobenzenesulfonimide as nitrogen source under mild reaction conditions has been described. The designed reaction strategy was triggered by trapping of fluorine by base with subsequent attack of bis(phenylsulfonyl)‐λ2‐azane on the carbonyl carbon of a heterocycle, which was gradually converted into the corresponding amine through a Curtius