Highly efficient construction of 2,3-disubstituted indoline derivatives by [4 + 1] annulation of sulfur ylides and o-sulfonamido aldimines

Abstract

Presented herein, a formal [4+1] cycloaddition of o-sulfonamido aldimines and sulfur ylides has been successfully developed. This strategy led to a series of 2,3-disubstituted indoline derivatives with synthetically flexible carbonyl...

Highly Regio- and Diastereoselective Phosphine-Catalyzed [2 + 4] Annulation of Benzofuran-Derived Azadienes with Allyl Carbonates: Access to Spiro[benzofuran-cyclohexanes]

“…According to the known procedure, K 2 CO 3 (10.2 mg, 0.03 mmol) and MeI (4.6 μL, 0.074 mmol) were added to a solution of 3a (20.5 mg, 0.037 mmol) in DMF (1 mL) at 0 °C. The resulting reaction mixture was stirred at rt for 12 h. The reaction was quenched with saturated NH 4 Cl, and the mixture was extracted with CH 2 Cl 2 .…”

Visible-Light-Induced Monofluoroalkenylation and gem-Difluoroallylation of Inactivated C(sp3)–H Bonds via 1,5-Hydrogen Atom Transfer (HAT)

“…Organofluorine molecules have found wide applications in pharmaceutical, agrochemical, and material industries due to their higher lipophilicity, metabolic stability, membrane permeability, and bioactivity compared with parent molecules. , Approximately, 20–30% of pharmaceuticals and 30–40% of agrichemicals on the market contain at least one fluorine atom . Among them, fluoroalkenes that contain monofluoroalkene motifs play a unique role in bioactive molecules as they are valuable as a peptide bond mimic in medicinal chemistry and drug discovery (Scheme a) .…”

One-pot synthesis of 4-(imidazol-1-yl)indole derivatives through a sequential dearomatization and Ag-catalyzed cyclization/Cs2CO3-mediated addition/aromatization reaction

“…10,11 Through oxidative dearomatization, o -alkynylanilines 1 b ,12 could be converted to the corresponding o -alkynyl cyclohexadienimines, which are useful starting materials for the assembly of substituted indoles due to their diverse functionality and excellent reactivity. 8,13 In this context and to continue our recent interest in exploring new atom- and step-economical methods for the synthesis of N-heterocycles, 14 herein we developed an expedient synthesis of 4-(imidazol-1-yl)indole derivatives from N -sulfonyl o -alkynylanilines and imidazoles through two-step sequential reactions involving a dearomatization and a Ag( i )-catalyzed cyclization/cesium carbonate-mediated conjugate addition/aromatization cascade process (Scheme 1, eqn (5)). As an important compensation of the previously reported addition/cyclization/aromatization reactions of o -phenylethynyl cyclohexadienimines, 8,13,15 the present work indicates that the combined use of a Lewis acid and cesium carbonate plays a significant role in the relevant domino transformation.…”