Front Cover: Palladium(0)‐Catalyzed Anti‐Selective Addition‐Cyclizations of Alkynyl Electrophiles (Chem. Eur. J. 6/2023)

Abstract

Pink and blue electrical cords represent bond formation that gives the endo‐ and exo‐adducts, respectively, shown on the light bulbs. The electrical plugs highlight the alkyne carbons attacked by the palladium catalyst, which then undergoes transmetalation with the arylboronic acid. Typical combinations of the ligand and alkyne substituent to give endo‐ and exo‐adducts are shown on the boxes at the end of the outlets. Methanol as solvent not only activates the carbonyl oxygen, but also promotes transmetalation with the arylboronic acid. More information can be found in the Research Article by H. Tsukamoto and co‐workers. (DOI: 10.1002/chem.202203068).

Recent Progress in Arylmetalative Cyclization/Annulation of Functionalized Alkynes with Organoboranes

“…Further, the same group reported the synthesis of aryl pipyridines from in situ formed imine electrophile (Scheme 27b) [39b] through intermediate B , and also extended the same for unsymmetrical diaryl acetylenes for the synthesis of indene derivatives (Scheme 27c) [39c] . Very recently, same group [39d] reported the palladium‐catalyzed anti ‐selective addition‐cyclization approaches of alkynyl electrophile through ‘anti‐waker’ type cyclization [40] . However, these pathways are outlined to the aryl‐metalation object, which we have taken into account due to mere‐anti addition.…”