Gold-Catalyzed Cyclizations of 4-Alkyl-2-yn-1-yl (Oxy)cyclohexa-2,5-dien-1-ones (<b>1</b>) to Develop Two Cyclizations via π-Alkyne versus π-Allene Activations.

ABSTRACT: This work reports two new gold-catalyzed cyclizations of 4-alkyl-2-yn-1-yl (oxy)cyclohexa-2,5-dien-1-ones (1) via gold-π-allene versus gold-π-alkyne routes, The π-allene route involves a [3.3] Claisen rearrangement of 1-alloxyallene intermediates to enable a 1,3-group migration, ultimately affording 2-substituted 3-formylbenzofurans (2). Density functional theory (DFT) calculations support this proposed mechanism in which water plays a key role. An alternative π-alkyne route contains cocatalyst PhNH₂ (10 mol %), leading to the formation of C_3,4-fused tetrahydrobenzofuran-5(4H)-ones (3) stereoselectively.

SUBMITTER: Kshirsagar AS 

PROVIDER: S-EPMC12836350 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature