Construction of nine-membered N,N,O-heterocycles via Pd-catalyzed [6+3] dipolar cycloaddition

Abstract

A new approach for the synthesis of 9-membered N,O-heterocycles by Pd-catalyzed [6+3] dipolar cycloaddition of N-iminoisoquinolinium ylides and 2-vinyl oxetanes has been developed. The scope of this cycloaddition was demonstrated...

Type of Tetrahydronaphthalene-Fused 1,5-Dipoles and Their Application in Polycyclic Compounds Synthesis

“…For example, Shi et al, Chen et al, and Deng et al , have successively used indole-fused dipole precursors for the synthesis of indole-fused polycyclic compounds. Recently, we have also been committed to the study of dipolar chemistry by developing cascade strategies and new dipole precursors . To develop strategies for the efficient synthesis of polycyclic compounds with a tetrahydronaphthalene structural fragment, we envisioned the introduction of a vinylethylene carbonate unit onto the tetrahydronaphthalene ring (Scheme b), which may allow cycloaddition with suitable reaction partners to construct polycyclic compounds.…”

Studies on the [4 + 2] cycloaddition and allylic substitution of indole-fused zwitterionic π-allylpalladium

“…Inspired by these previous works, as well as our recent interest in the area of Pd-catalyzed annulation reactions, 12 our next objective is to synthesize a new precursor compound by adjusting the position of allyl substitution from the 2-position to the 7-position of indole (Fig. 1c).…”

Construction of diverse polycyclic N-heterocycles via cascade allylic amination/Diels–Alder reaction

“…In continuation of our efforts in developing new methodologies for the synthesis of heterocycles, 9 we envisaged that the intramolecular Diels–Alder reaction of intermediate A , which is accessible from the allylic amination 10 between vinyl amines B and 1,4-pentadiene derivatives C , would provide the valuable hydrophenanthridine core. To achieve the designed annulation reaction, the employment of 1,4-pentadiene C as the precursors to allyl metal is key to success.…”