Pd-Catalyzed Autotandem Reactions with N-Tosylhydrazones. Synthesis of Condensed Carbo- and Heterocycles by Formation of a C–C Single Bond and a C═C Double Bond on the Same Carbon Atom

Abstract

A new Pd-catalyzed autotandem reaction is introduced that consists of the cross-coupling of a benzyl bromide with a N-tosylhydrazone followed by an intramolecular Heck reaction with an aryl bromide. During the process, a single and a double C-C bond are formed on the same carbon atom. Two different arrangements for the reactive functional groups are possible, rendering great flexibility to the transformation. The same strategy led to 9-methylene-9H-fluorenes, 9-methylene-9H-xanthenes, 9-methylene-9,10-dihydroacridines, and also dihydropyrroloisoquinoline and dihydroindoloisoquinoline derivatives.

Palladium‐Catalzyed Atroposelective 16‐Membered Macrocyclization: Total Synthesis of Isoplagiochin D†

“…Thus, the Pd‐catalyzed styrenes synthesis between benzyl chloride and arylhydrazones became an ideal reaction for our strategy. [ 39‐51 ] The key cyclic palladium complex 13 would give 14 via migration and insertion. The β‐elimination of 14 afforded the key intermediate 15 .…”

Synthesis of Acridines through Alkyne Addition to Diarylamines

“…Both of these methods typically require further processing to aromatize the acridine ring following closure. Though some tandem processes have been shown previously, none incorporates alkynes in a manner similar to this work [ 24 , 25 , 26 , 27 ]. Two elegant C-H activation papers have been produced, both beginning with already-formed acridine [ 28 , 29 ].…”

Recent Development in Palladium-Catalyzed Domino Reactions: Access to Materials and Biologically Important Carbo- and Heterocycles

“…The same strategy led to, 9-methylene-9H-xanthenes, 9-methylene-9,10-dihydroacridines, and also dihydropyrroloisoquinoline and dihydroindoloisoquinoline derivatives. 58 Scheme 37. Synthesis of 9-methylene-9H-fluorenes.…”