Gold-catalyzed intramolecular hydroamination of allenes: a case of chirality transfer

Gold(III) Chloride

“…58 Saturated pyrrolidine derivatives can also be synthesized using gold(III) chloride as catalyst. 59 However, when the amine was left unprotected, no desired product was observed. Moreover, the free amino group of a β-lactam can undergo an intramolecular hydroamination of allene.…”

Gold‐Catalyzed Addition of Nitrogen and Sulfur Nucleophiles to CC Multiple Bonds

“…Yamamoto has reported the intramolecular exo-hydroamination of N-allenyl sulfonamides and carbamates catalyzed by simple, unligated gold(I) and gold(III) salts. Noteworthy was that cyclization of N-allenyl sulfonamide derivatives that possessed an axially chiral allenyl moiety occurred with highly selective transfer of chirality to the newly formed tetrahedral stereogenic carbon atom [38]. For example, treatment of enantiomerically enriched c-allenyl tosylamide 52 (96% ee) with a catalytic amount of AuCl in THF at room temperature led to isolation of (E)-2-(1-heptenyl)pyrroldine (E)-53 in 99% yield with 94% ee (Eq.…”

Recent Progress in the Chemistry of Allenes

“…Intramolecular cyclization of allenes with tethered amines, formerly known as hydroamination [143], in the presence of a transition metal catalyst represents the most common route for generating nitrogen-containing heterocycles. Recently, Yamamoto [144] found that Au(I) or Au(III) catalysts promote a highly efficient intramolecular hydroamination of allenes under very mild conditions. The method allowed the synthesis of five and six-membered nitrogen heterocycles in high yields and in an atom economical manner that allow further applications towards the synthesis of natural products.…”