Ruthenium-Catalyzed Carbonylation of α-Aminoaryl-Tethered Alkylidenecyclopropanes: Synthesis of Eight-Membered Benzolactams

Abstract

The synthesis of medium-sized lactams is a great challenge because of the unfavorable transannular interactions and entropic barriers in the transition state. We have developed a ruthenium-catalyzed carbonylation of α-aminoaryl-tethered alkylidenecyclopropanes (ACPs) that allows for the efficient preparation of valuable eight-membered benzolactams under ligand-free conditions. The amino group served a dual role of both directing group and nucleophile to facilitate the metallacycle formation and the carbonylation.

Palladium-catalyzed selective C–C bond cleavage of keto-vinylidenecyclopropanes: construction of structurally rich dihydrofurans and tetrahydrofurans

“…In the past few decades, the reaction of proximal C–C bond cleavage of alkylidenecyclopropanes has made significantly effective progress. 9 As for activated VDCPs, our group's previous work has disclosed the palladium-catalyzed and Lewis acid-assisted proximal C–C bond cleavage of the vinylidenecyclopropane-diester as shown in Scheme 2 . 10 In this proximal C–C bond cleavage, a η 1 -(allenyl)palladium species II-1 is produced, which can be transformed into η 3 -(propargyl)palladium species II-2 and η 1 -(propargyl)palladium species II-3 to undergo the downstream transformations.…”