Photocatalytic decarboxylative alkylation of silyl enol ether and enamide with N-(acyloxy)phthalimide using ammonium iodide

Abstract

Enamides and silyl enol ethers were alkylated to deliver products of N-acyl imines and ketones in the presence of a catalytic amount of N-tetrabutylammonium iodide under irradiation of purple light...

Recent Advances in Employing Catalytic Donors and Acceptors in Electron Donor–Acceptor Complex Photochemistry

“…Since the seminal work by Shang and Fu in 2019, many reports have demonstrated that iodide salts, even in the absence of PPh 3 , can act as a donor catalyst for EDA complex photochemistry. ,− In one example distinct from the other EDA complexes described in this Synopsis, Fu and co-workers leveraged the ion-pair charge-transfer state of pyridinium iodides to photocatalyze the cyclization of N -vinyl amides to form substituted oxazolines . Their proposed mechanism is outlined in Scheme .…”

“…Visible-light excitation of EDA complex E furnishes a perfluoroalkyl radical and hydroquinone radical cation 30, which is subsequently deprotonated to yield phenoxy radical 31. The resulting perfluoroalkyl radical then adds to an electron-rich heterocycle or arene (32) to furnish radical intermediate 33. The crucial catalyst turnover step involves a hydrogen-atom transfer (HAT) between 31 and 33 to yield perfluoroalkylated product 34 and regenerating 29.…”

Visible light-promoted, photocatalyst-free decarboxylative alkylation of 2H-indazoles via electron donor–acceptor complex activation

“…The EDA complex strategy has attracted considerable attention in recent years owing to the concomitant circumvention of the requirement of a photocatalyst and stoichiometric oxidant. [24][25][26][27][28][29][30][31][32][33][34][35] The electron-rich donor and the electron-deficient acceptor form a molecular aggregate through non-covalent interaction, which generates valuable radicals through visible light-mediated single electron transfer (SET). In 2019, the elegant works of Shang, Fu, and co-workers revealed that triphenylphosphine (PPh 3 ) and sodium iodide (NaI) systems could be used for photocatalytic alkylation.…”

Synthesis and development of seven-membered constrained cyclic urea based PSMA inhibitors via RCM

“…37 The addition of a catalytic amount N -tetrabutylammonium iodide (TBAI) was crucial to improving the yields of 9 from an initial 45–60% to 78%. 38…”

“…37 The addition of a catalytic amount N-tetrabutylammonium iodide (TBAI) was crucial to improving the yields of 9 from an initial 45-60% to 78%. 38 Selective 2-nosyl removal on 9 was achieved via nucleophilic substitution with 1,4-dithiothreitol (DTT) and 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) to effectively cleave the 2-nosyl protecting group using repurposed conditions described by Miller et al via substitution of the thiol nucleophile affording 4 in 86% yield. 36 In our hands, nucleophilic aromatic substitution utilizing thiophenol to remove the 2-nosyl group resulted in a significant by-product that co-eluted with 4 hampering purification by flash-chromatography.…”