Modular approach to non-aromatic and aromatic pyrroles through gold-catalyzed [3 + 2] cycloaddition of 2H-azirines and ynamides

Abstract

The developed modular approach to hard-to-reach non-aromatic 3H- and 2H-pyrroles is based on the integration of 2H-azirines and ynamides. Gold-catalyzed [3+2] cycloaddition of 2,2-disubstituted 2H-azirines and ynamides comprises a high...

Gold‐Catalyzed Annulation of Ynamides with Aminocarbonyls as a Route to 2‐Aminoquinolines Diversely Substituted at the 4th‐Position

“…Ynamides, i. e. amido-functionalized alkynes [23,24] have been commonly recognized as easily available and handy building blocks for a facile construction of complex molecules, [24][25][26][27] including diverse carbo-and heterocycles. [28][29][30][31][32][33][34] Owing to the high polarization, the ynamide C � C triple bond is sensitive to the action of various nucleophilic reagents. Additionally, electrophilic activation of ynamides by Brønsted [35,36] or Lewis acids (especially gold-containing compounds [37][38][39] ) allows the selectivity control of ynamide-based transformations.…”

Alkoxymigration onto α‐Imino Gold Carbenes for Constructing Propellane‐Type Indolines

“…Transformations that lead to rearrangements with a tethered nucleophilic functional group can rapidly generate multiple cyclic frameworks with high sp 3 ‐content and an increasing number of stereocenters in a single operation. Such features render homogenous gold catalysis attractive for optimizing molecular complexity [10–21] . We expect that gold carbene chemistry in conjunction with rearrangement/migration offers an efficient approach to propellane‐type scaffolds.…”

Synthesis of 2-Aminopyrroles Via Metal-Free Annulation of Ynamides with 2H-Azirines

“…Recently, transition metal-catalyzed cyclizations of activated alkynes have emerged as an alternative strategy for the synthesis of 2-aminopyrroles, − in which gold-catalyzed reactions of ynamides account for a large part. The Au­(I)- or Ag­(I)-catalyzed formal [3 + 2] cycloadditions of ynamides with isoxazoles (Scheme a), azidoalkenes (Scheme b), or 2 H -azirines (Scheme c) , have been achieved successively, allowing practical and flexible access to a wide range of polysubstituted 2-aminopyrroles. However, these transition metal-catalyzed cyclizations of ynamides provide 2-aminopyrroles with the restriction of substituents at their 3-positions.…”