Palladium-catalyzed [4 + 2] cycloaddition of amido-tethered allylic carbonates with oxazol-5-(4H)-ones: synthesis of piperidine-2,6-dione derivatives

Abstract

A palladium-catalyzed [4+2] cycloaddition of amido-tethered allylic carbonates with oxazol-5-(4H)-ones proceeded smoothly under mild reaction conditions to give various piperidine derivatives in moderate to excellent yields. The reaction worked via...

Palladium-catalyzed decarboxylative α-allylation of thiazolidinones and azlactones with sulfonamido-substituted acyclic allylic carbonates

“…Based on the experimental observations and previous literature, 6–13 a mechanism was proposed, as shown in Scheme 6. Under the catalysis of the PdL complex, the decarboxylation of sulfonamido-substituted acyclic allylic carbonates 2 results in aza-π-allylpalladium zwitterionic intermediates A along with the extrusion of CO 2 and t BuOH.…”

“…Over the past few years, various precursors have been designed, synthesized and applied for different types of palladium-catalyzed decarboxylative chemical transformations. 6–13 Through in-depth literature research, it was found that the precursors to in situ form π-allylpalladium zwitterionic intermediates via a decarboxylation process mainly include cyclic vinyl carbonates, lactones and oxazolidin-2-ones (Scheme 1a), such as vinylethylene carbonates, 6 2-alkylidenetrimethylene carbonates, 8 γ-methylidene-δ-valerolactones, 9 vinyl benzoxazinones, 10 and vinyl methylene cyclic carbonates. 11 An alternative way for generating π-allylpalladium zwitterionic intermediates is to use acyclic allylic carbonates, and almost all studies focused on Pd-trimethylenemethane (TMM) zwitterionic intermediates containing a ligand-ligated π-allylpalladium cation and a carbanion counterpart (Scheme 1b).…”

Preparation of N- and C-Functionally-Substituted Glutarimides: A Review

“…In 2023, Wang with co-authors 40 published an article on the synthesis of glutarimides 40 by the reaction of tert-butyl (1-alkyl-2-(phenylcarbamoyl)hallel)carbonates 38 with 4-(alkyl)-2-aryloxazole-5(4H)-one 39. The reaction is car-ried out in a dichloromethane medium in a nitrogen atmosphere with catalysis from various diphenylphosphine derivatives and a palladium salt (Scheme 18).…”

Palladium-Catalyzed [5 + 4] Cycloaddition of 4-Vinyl-4-Butyrolactones with N-Tosyl Azadienes: Construction of Nine-Membered Ring

“…Based on these works involving VBLs, in order to synthesize biologically significant nine-membered heterocycles, we continued to explore Pd-catalyzed [5 + 4] cycloaddition of π-allyl-Pd all-carbon-1,5-dipoles from VBLs with azadienes, which is an effective four-atom unit for cycloaddition reactions owing to the driving force of aromatization . As our continuous efforts in cycloaddition reactions, we herein described a Pd-catalyzed [5 + 4] cycloaddition of VBLs with azadienes to afford an array of nine-membered aza-heterocycles (Scheme c).…”