B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>‑Catalyzed\nMulticomponent Reactions of 2,3-Diketoesters, Amines, Allenes, and\nNucleophiles: Synthesis of 2α-Functionalized Pyrroles

An efficient B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-catalyzed\nmulticomponent reaction of 2,3-diketoesters, amines, allenes, and\nnucleophiles was reported, which afforded 2α-functionalized\npyrroles in moderate to good yields. The reaction features low catalyst\nloading, usage of a small amount of solvent, high atom economy, tunable\ninstallation of diverse functional groups at 2α-position, and\nwater being formed as the byproduct. This is the first multicomponent\nreaction that combines vicinal tricarbonyl compounds with allenes.