Enantioselective Three‐Component Coupling of Heteroarenes, Cycloalkenes and Propargylic Acetates

Abstract

Asymmetric coupling proceeds efficiently between propargylic acetates, cycloalkenes and electron‐rich heteroarenes including indoles, pyrroles, activated furans and thiophenes. 2,3‐Disubstituted tetrahydrofurans and pyrrolidines are produced in trans configuration and excellent enantiomeric ratios. The reaction proceeds via Wacker‐type attack of nucleophilic heteroarenes on alkenes activated by allenyl PdII species.

Synthesis of Multisubstituted Allenes via Nickel-Catalyzed Cross-Electrophile Coupling

“…The solvent was removed, and the residue was subjected to column chromatography (petroleum ether/ethyl acetate 20:1) on silica gel to afford the (R)-1-(4-methoxyphenyl)-2-(1-methyl-2,3-dihydro-1H-inden-1-yl)ethan-1-one (8) as a colorless oil (38 mg, 67%, 95% ee). Pd/C-Catalyzed Hydrogenation of 5aa 8 10 wt% Pd/C (53.2 mg, 0.05 mmol, 25 mol%) was added to a stirred solution of 5aa (63.6 mg, 0.2 mmol) in a mixture of anhydrous MeOH/DCM (3:1, 2 mL). The reaction mixture was stirred under a hydrogen balloon at room temperature for 12 hours.…”