A Short Synthesis of (±)‐3‐Demethoxyerythratidinone by Ligand‐Controlled Selective Heck Cyclization of Equilibrating Enamines
نویسندگان
چکیده
A short, 5-step total synthesis of (±)-3-demethoxyerythratidinone from a simple pyrrole derivative is described. Features include the formation of gram quantities of a key tricylic aziridine from a challenging photochemical cascade reaction through the use of flow photochemistry. The final step involved a highly unusual Heck cyclization whereby ligand control enabled efficient formation of the natural product in 69 % yield from the minor isomer present in an equilibrating mixture of labile enamines.
منابع مشابه
Synthesis, Characterization and Catalytic Activity of Ligand Stabilized Palladium Nanoparticle: A Catalyst Compliment to the Heck Coupling Reaction
The palladium metal is the most frequently used metal because of its excellent catalytic efficiency and most flexible varying oxidation state. So, we report that palladium nanoparticles (Pd NPs) stabilized by a ligand (o-vanilindiphenylethanedionedihydrazone, L) using reverse micelles method have been synthesized, while all particles are in spherical shape and ranging between 10 and...
متن کاملSynthesis of novel tridentate ligand-based palladium catalyst and investigation of its reactivity towards Suzuki, Sonogashira and Heck coupling reactions
We have demonstrated a simple and efficient route for the synthesis of a novel imine based tridentate ligand and its Pd-complex to investigate the C-C cross-coupling reactions, that involve column chromatography purification in only one step. The catalytic activity of the newly synthesized catalyst was studied for the Suzuki, Sonogashira and, Heck cross-coupling reactions under mild conditions....
متن کاملOxidative tandem nitrosation/cyclization of N-aryl enamines with nitromethane toward 3-(trifluoromethyl)quinoxalines.
A novel one-pot strategy for the synthesis of 3-trifluoromethylquinoxalines from N-aryl enamines and nitromethane was developed. The tandem reaction is achieved through nitrosation of alkenes, tautomerization and cyclization, which can be applicable to a wide range of enamines with excellent functional group tolerance and afford quinoxalines in moderate to good yields.
متن کاملLigand-controlled regiodivergent nickel-catalyzed annulation of pyridones.
The 1,6-annulated 2-pyridone motif is found in many biologically active compounds and its close relation to the indolizidine and quinolizidine alkaloid core makes it an attractive building block. A nickel-catalyzed C-H functionalization of 2-pyridones and subsequent cyclization affords 1,6-annulated 2-pyridones by selective intramolecular olefin hydroarylation. The switch between the exo- and e...
متن کاملSELECTIVE CYCLIZATION AND IS OMERIZATION OF 3-PROPARGYLTHIO- 1,2,4- BENZOTRIAZINE TO THIAZOLO [2,3-C] [1,2,4] BENZOTRIAZINE
The method cited in the literature for synthesis of 1,2- dihydro 3- thioxo - 1,2,4- benzotriazine 1 was improved .1 was condensed with propargyl bromide to afford 3 - propargylthio – 1,2,4 -benzotriazine 5. Transformation of this compound to 9H-3- methylthiazolo [2,3-c] [1,2,4] benzotriazine ( 3, R = Me) was performed in the presence of Na O Me / MeOH . Orientation of this selective cy...
متن کامل