Palladium(0)‐Catalyzed Intermolecular Carbocyclization of (1,n)‐Diynes and Bromophenols: An Efficient Route to Tricyclic Scaffolds

Abstract

A novel palladium(0)-catalyzed dearomative cyclization reaction of bromophenols with (1,n)-diynes has been developed for building two new types of tricyclic architectures containing a quaternary carbon center. This method employs inexpensive bromophenols, and easily accessible tethered diynes. It exhibits a broad substrate scope and tolerates various functional groups. Preliminary results with commercially available chiral ligands indicate that enantioselective variants are feasible for both cyclization processes.

Modular Assembly of Spirocarbocyclic Scaffolds through Pd0‐Catalyzed Intermolecular Dearomatizing [2+2+1] Annulation of Bromonaphthols with Aryl Iodides and Alkynes

“…Upon optimization on the base, the envisioned 4 a was indeed obtained, albeit with low yields (entries 2–3). Despite this encouraging outcome with the use of Cs 2 CO 3 , the desired transformation suffered from the concomitant generation of byproducts 5 a , 6 a , and 7 a . Other common solvents and palladium precursors for Catellani‐type reactions were tested, but none of them showed a positive effect (entries 4–7).…”

Palladium‐Catalyzed Double Cyclization Processes Leading to Polycyclic Heterocycles: Recent Advances

“…Diyne substrates may undergo carbocyclization via sequential insertion of the two triple bonds into an Ar–PdX bond. Under suitable conditions, and with particular substrates, this may be followed by intramolecular dearomative palladation and reductive elimination, as shown in Scheme for the synthesis of tetracyclic fused spirocycles …”

Palladium‐Catalyzed Acylation Reactions: A One‐Pot Diversified Synthesis of Phthalazines, Phthalazinones and Benzoxazinones

“…Sequential one‐pot transformations are essential for chemical synthesis, because they enable the formation of more than one bond, which thereby facilitates the formation of products with sufficient complexity. Also, they are economically and ecologically viable processes, because they save time, energy and reduce the amount of waste formed.…”