Synthesis of Polycyclic Hydrocarbons by Palladium-Catalyzed Cross-Coupling Reactions of Vinylic Bromides with Diphenylacetylene

Abstract

Vinylic bromides of type 1 undergo cross‐coupling reactions with diphenylacetylene (5) leading to various polycyclic hydrocarbons. The ratio of the 1:1 to the 1:2 products can readily be controlled by varying the reaction conditions.

Recent Advances in the Chemistry of Pentafulvenes

“…Yamamoto and co-workers then extended this original transformation using terminal alkynes to yield pentafulvenes with three substitutions on the endocyclic ring . Earlier reports on the transition metal-catalyzed synthesis of pentafulvenes had some limitations, such as the need for elevated temperatures, moderate yields, and a lack of generality. , Takahashi and co-workers overcame all of these constraints by developing a novel synthetic route to pentasubstituted pentafulvenes from two alkynes and an alkenyl iodide through palladium catalysis (Scheme b) . It is interesting to note that, in addition to the palladium catalyst, the silver salt and carbonate ions significantly affect this reaction.…”

A Domino Palladium-Catalyzed Cyclization: One-Pot Synthesis of 4b-Alkyl-10-phenyl-4b,5-dihydroindeno[2,1-a]indenes via Carbopalladation Followed by C–H Activation

“…In this context, the transition-metal-catalyzed annulations of internal alkynes have received much attention to access complex cyclic frameworks . Among them, [Pd]-catalyzed domino cyclizations have been widely investigated . Consequently, remarkable contributions have been made by the research group of Larock toward the annulation processes of internal alkynes for the synthesis of a variety of cyclic systems .…”

Ein Dominoprozess zu Dibenzopentafulvalenen mittels vierfacher Carbopalladierung

“…In den letzten zwei Jahrzehnten wurde eine Vielzahl von DominoCarbopalladierungssequenzen entwickelt, welche zu homound heterocyclischen Systemen wie Lactonen, Chromanen, molekularen Schaltern und weiteren komplexen Produkten in einem einzigen Schritt ausgehend von verhältnismäßig einfachen Startmaterialien führten. [13][14][15] Unser hier vorgestellter Ansatz erzeugt das Pentafulvalengerüst in einem einzigen Schritt über eine vierfache Carbopalladierungssequenz. Die retrosynthetische Überlegung war, das Gerüst durch die Verwendung von leicht verfügba-rem Biphenylacetylen und zwei verbrückten Alkineinheiten (wie in 4) aufzubauen (Schema 1, unten).…”