Silver Nanoparticle-Catalyzed Diels−Alder Cycloadditions of 2′-Hydroxychalcones

Iridium-catalyzed intramolecular [4 + 2] cycloadditions of alkynyl halides

Iridium-catalyzed intramolecular [4 + 2] cycloadditions of diene-tethered alkynyl halides were investigated by using [IrCl(cod)](2) as catalyst, and dppe was found to be the most suitable phosphine ligand for the reaction. No oxidative insertion of the iridium into the carbon-halide bond was observed, and the reactions proceeded to provide the halogenated cycloadducts in good yield (75-94%). Th...

Iridium–catalyzed 1,3–dipolar cycloadditions

1,3–Dipolar cycloaddition reactions (DCR) are atom–economic processes that permit the construction of heterocycles. Their enantioselective versions allow for the creation of up to four adjacent chiral centers in a concerted fashion. In particular, well–defined half–sandwich iridium (III) catalysts have been applied to the DCR between enals or methacrylonitrile with nitrones. Excellent yield and...

Enantioselective copper-catalyzed 1,3-dipolar cycloadditions.

Metal-catalyzed [2+2+1] cycloadditions of 1,3-dienes, allenes, and CO.

Article: Step economy is a preeminent goal of synthesis. [1] It influences the length, efficiency, cost, time, separation, and environmental impact of a synthesis. Step economy is favored by the use of single, serial, or multicomponent reactions that proceed in one operation with a great increase in target revelant complexity. The design or discovery of such reactions is thus critical to extend...

Reactivity and Chemoselectivity of Allenes in Rh(I)-Catalyzed Intermolecular (5 + 2) Cycloadditions with Vinylcyclopropanes: Allene-Mediated Rhodacycle Formation Can Poison Rh(I)-Catalyzed Cycloadditions

Allenes are important 2π building blocks in organic synthesis and engage as 2-carbon components in many metal-catalyzed reactions. Wender and co-workers discovered that methyl substituents on the terminal allene double bond counterintuitively change the reactivities of allenes in [Rh(CO)2Cl]2-catalyzed intermolecular (5 + 2) cycloadditions with vinylcyclopropanes (VCPs). More sterically encumbe...