Photosensitizer-free, visible light-mediated heterogeneous gold-catalyzed cross-coupling of aryldiazonium salts with allyltrimethylsilane

An efficient visible light-mediated and heterogeneous gold-catalyzed cross-coupling of aryldiazonium tetrafluoroborates and allyltrimethylsilane has been developed. The photosensitizer-free cross-coupling reaction proceeds smoothly in MeCN under irradiation with blue LEDs at room temperature by using 10 mol% of SBA-15-supported triphenylphosphine-gold(I) complex [SBA-15-Ph3PAuCl] as catalyst and provides a general and practical route for the synthesis of allylarenes in moderate to good yields. This heterogenized gold(I) catalyst can be readily recovered via a simple filtration of the reaction mixture and recycled up to eight times without any significant loss of catalytic activity.</p

Synthesis of Indolyl Imidazole Derivatives via Base-Promoted Tandem Reaction of <i>N</i>‑[2-(1-Alkynyl)phenyl]carbodiimides with Isocyanides

An efficient route to indolyl imidazole derivatives has been developed through a base-promoted tandem reaction of <i>N</i>-[2-(1-alkynyl)­phenyl]­carbodiimides with isocyanides in DMSO at 40 °C. The present tandem process allows the assembly of a variety of indolyl imidazole derivatives in moderate to good yields

An efficient and practical synthesis of functionalized pyridines via recyclable copper-catalyzed three-component tandem cyclization

An efficient heterogeneous copper(I)-catalyzed three-component tandem cyclization of ketoxime acetates, aldehydes, and activated methylene compounds has been developed that proceeds smoothly in DMSO at 120 °C by using an 3-(2-aminoethylamino)propyl-modified MCM-41-bound copper(I) bromide [MCM-41-2N-CuBr] as the catalyst, delivering a variety of polysubstituted pyridines in good to high yields. The heterogenized copper(I) catalyst can be readily obtained via a simple preparative procedure from commercially available and inexpensive reagents, and reused more than seven times without any apparent drop in its catalytic efficiency. </p

Facile synthesis of arylboronates via recyclable copper(I)-catalyzed cross-coupling of pinacolborane with aryl iodides under mild conditions

An efficient heterogeneous copper(I)-catalyzed cross-coupling of aryl iodides and pinacolborane has been developed. The reaction proceeds smoothly in THF at room temperature by using 10 mol% of MCM-41-anchored NHC-copper(I) complex [MCM-41-NHC-CuI] as catalyst and sodium hydride as base and provides a general and practical route for the synthesis of a wide variety of arylboronates in good to high yields. This heterogenized copper(I) catalyst can be facilely prepared via a simple two-step procedure starting from easily accessible and inexpensive reagents, and exhibits a higher catalytic activity than CuI and can be recycled more than ten times without any significant loss of its catalytic activity.</p

Recyclable and Reusable [RuCl₂(<i>p</i>‑cymene)]₂/Cu(OAc)₂/PEG-400/H₂O System for Oxidative C–H Bond Alkenylations: Green Synthesis of Phthalides

[RuCl₂(<i>p</i>-cymene)]₂ in a mixture of poly­(ethylene glycol) (PEG-400) and water is shown to be an extremely efficient catalyst for the cross-dehydrogenative C–H bond alkenylation reaction between benzoic acids and alkenes. The reaction could be conducted at 80 °C using Cu­(OAc)₂·H₂O as oxidant, yielding a variety of phthalide derivatives in good to excellent yields. More importantly, both [RuCl₂(<i>p</i>-cymene)]₂ and Cu­(OAc)₂ in the PEG-400/H₂O system could be easily recycled and reused six times without any loss of catalytic activity