Gold-Catalyzed Tandem Cyclizations of 1,6-Diynes Triggered by Internal N- and O-Nucleophiles

Abstract

Investigations on gold-catalyzed tandem cyclization reactions of 1,6-diynes, tethered to nucleophilic functionalities such as amine, carboxylic acid, amide, and sulfonamide, are reported. The ability of such substrates to undergo tandem cyclization, triggered by internal nucleophiles, has been examined. Depending on the substrate, the catalytic system, and reaction conditions, different regioisomers of monocyclic and bridged bicyclic products were obtained.

Gold(I)-Catalyzed Activation of Alkynes for the Construction of Molecular Complexity

“… 195 An analogous process has been developed by the intramolecular addition of other nucleophiles such as carboxylic acids or nitrogen nucleophiles to 1,6-diynes. 196 …”

Alkyne hydroamination triggered cyclizations: A powerful tool for the construction of biologically important structural motifs

“…Recently, Fiksdahl and Sperger reported the gold(I)-catalyzed hydroamination triggered cycloisomerization reactions [39]. They designed 1,6-diynes of type 28 that undergoes formation of various products 29/30/31 under gold catalysis and the product distribution depends on the type of catalyst used (Table 4).…”

Gold(I)‐Catalyzed Cycloisomerization of 3‐Alkoxyl‐1,6‐diynes: A Facile Access to Bicyclo[2.2.1]hept‐5‐en‐2‐ones

“…However, only ten successful examples were reported . Fiksdahl and co‐workers discovered an useful access to bicyclic lactones by combining an initial lactone formation and a second enyne cyclization, but the selectivity remained a challenge and the best yield was 59 % …”