A highly
efficient, green palladium-catalyzed cyclocarbonylation
of 2-iodoanilines with acyl chlorides has been developed that proceeds
smoothly in a biomass-derived solvent 2-methyltetrahydrofuran with N,N-diisopropylethylamine as base at 100
°C under 20 bar of carbon monoxide using an 2-aminoethylamino-modified
MCM-41-anchored palladium acetate complex [2N-MCM-41-Pd(OAc)2] as a heterogeneous catalyst, yielding a wide variety of 2-substituted
4H-3,1-benzoxazin-4-one derivatives in good to excellent
yields. This supported palladium catalyst could be facilely obtained
by a two-step procedure from easily available starting materials and
readily recovered via a simple filtration process and recycled at
least 8 times without any apparent decrease in catalytic efficiency.
The developed methodology not only avoids the use of toxic solvents
such as tetrahydrofuran and dimethylformamide but also solves the
basic problem of expensive palladium catalyst recovery and reuse and
prevents effectively palladium contamination of the desired product.
A highly efficient and practical heterogeneous palladium-catalyzed carbonylative coupling of 2-iodoanilines with aryl iodides has been developed. The reaction occurs smoothly in toluene at 110 °C with N,N-diisopropylethylamine as base under carbon monoxide (5 bar) and offers a general and powerful tool for the construction of various valuable 2-arylbenzoxazinones with excellent atom-economy, high functional group tolerance, good to high yields, and easy recyclability of the palladium catalyst. The reaction is the first example of heterogeneous palladium-catalyzed carbonylative coupling for the preparation of diverse 2-arylbenzoxazinones from commercially easily available 2-iodoanilines and aryl iodides.
An efficient heterogeneous palladium-catalyzed carbonylative annulation of 2-iodoanilines, trimethyl orthoformate, and amines has been developed. The reaction proceeds smoothly in toluene at 110 °C using N,N-diisopropylethylamine (DiPEA) as base and 2 mol% of MCM-41-anchored bidentate phosphine palladium complex [MCM-41-2P-Pd(OAc)2] as catalyst under 10 bar of carbon monoxide and provides a general and practical method for the construction of a wide variety of quinazolin-4(3H)-ones in good to excellent yields from commercially easily available starting materials. This heterogenized palladium catalyst can be easily recovered via a simple centrifugation process and reused more than nine times with almost consistent catalytic efficiency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.