Visible-Light-Promoted Photoredox Syntheses of α,β-Epoxy Ketones from Styrenes and Benzaldehydes under Alkaline Conditions

A range of styrenes and benzaldehydes were smoothly combined to form α,β-epoxy ketones under the synergistic actions of photocatalyst Ru­(bpy)₃Cl₂, <i>tert</i>-butyl hydroperoxide (<i>t</i>-BuOOH), cesium carbonate (Cs₂CO₃), and visible light irradiation. The process likely proceeds through visible-light-enabled photocatalytic generations of acyl radicals as key intermediates

Gold Catalysis Coupled with Visible Light Stimulation: Syntheses of Functionalized Indoles

A judicious combination of Au-catalysis and synergistic visible-light stimulation formulates an exceptionally simple and mild reaction system capable of directly coupling anilines and alkynes to form multifunctionalized indoles

Gold-Catalyzed Rearrangement of Alkynyl Donor–Acceptor Cyclopropanes To Construct Highly Functionalized Alkylidenecyclopentenes

A gold-catalyzed 1,7-addition–cyclization–elimination cascade sequence performed on a range of alkynyl-substituted donor–acceptor-type cyclopropanes provides facile entry to highly functionalized <i>exo</i>-alkylidenecyclopentenes under very mild conditions. Isolation of the relevant allyl ether intermediate helped shed light on the reaction’s mechanistic course

Tackling Reactivity and Selectivity within a Strained Architecture: Construction of the [6–6–5–7] Tetracyclic Core of <i>Calyciphylline</i> Alkaloids

A stereochemically controlled route to the enantiopure [6–6–5–7] tetracyclic core of <i>Calyciphylline</i> A class alkaloids was established, which involves Overman rearrangement, [2 + 2] photochemical cycloaddition, Grob fragmentation, C–N bond-forming nucleophilic displacement, and ring strain-directed hydrogenation as strategic steps

New Approach to Oximes through Reduction of Nitro Compounds Enabled by Visible Light Photoredox Catalysis

A range of nitro compounds are smoothly reduced to their corresponding oximes under the synergistic effects of visible light irradiation, the Ru(bpy)₃Cl₂ photocatalyst, Hünig’s base, Mg(ClO₄)₂ activation, and MeCN solvent. This remarkably mild and environmentally benign protocol, when orchestrated with classical Beckmann rearrangement, enables such high-value industrial feedstock as caprolactam to be readily accessed from simple precursor nitrocyclohexane

Visible-Light-Promoted Vinylation of Tetrahydrofuran with Alkynes through Direct C–H Bond Functionalization

Mild and direct C–H bond functionalizations and vinylations of tetrahydrofuran with alkynes have been accomplished through visible light photocatalysis, yielding a range of vinyl tetrahydrofurans under the synergistic actions of organic dye-type photocatalyst eosin Y, <i>tert</i>-butyl hydroperoxide (<i>t</i>-BuOOH), and a 45 W household lightbulb. A significant kinetic isotope effect (KIE) was recorded, which helps shed light on the mechanistic course

<i>Ortho</i>-Dearomatization of Phenols Creating All-Carbon Spiro-Bicycles

A range of alkene-linked phenols are generally and reliably dearomatized specifically at their <i>ortho</i>-positions to create all-carbon quaternary stereogenic centers at the corresponding spiro-ring junctions, thus establishing a viable solution to the long-standing synthetic challenge

Asymmetric Synthesis of the Tricyclic Core of <i>Calyciphylline</i> A‑Type Alkaloids via Intramolecular [3 + 2] Cycloaddition

Asymmetric synthesis of the [5–6–7] tricyclic system common to the <i>Calyciphylline</i> A-type alkaloids is reported, featuring Overman rearrangement, Heck cyclization, intramolecular [3 + 2] cycloaddition, diastereoselective hydrogenation, and Claisen rearrangement as strategic events. The approach is capable of installing the crucial carbonyl functionality as well as multiple stereogenic centers within a congested polycyclic ring skeleton

Ag-Carbenoid-Initiated Catalytic Hydration Cascades: Rapid Construction of Functionalized Bicyclo[3.3.1]nonanes

Remarkable Ag-carbenoid-initiated enone cyclopropanation–hydrolytic fragmentation–competitive 1,2-vs-1,4 addition reaction cascades were uncovered on a range of propargylic esters tethered to cyclohexadienones, leading to the highly efficient and stereospecific construction of densely functionalized bicyclo[3.3.1]nonanes under mild conditions