Palladium-catalyzed MCR

This reaction has been modified from acid-catalyzed cyclization of uredo acids from palladium catalyzed MCR among aldehydes, carbon monoxide, and ureas and from Ugi five-component condensation. Alternatively, hydantoins can also be synthesized via other methods, such as the 1,3-Dipolar Cycloaddition of l-oxa-4-azabutadiene and aryl isocyanates and the decomposition of barbituric acids in alcohol. ... 

Palladium-Catalyzed MCRs Containing Organoboron Compounds... 

Flynn and coworkers have used a palladium-catalyzed MCR to construct the benzo[ ]furan core of frondosin B 49 (Scheme 6.21) [23], a strategy that they have already established for the synthesis of some analogues of the anticancer compound combretastatin A-4 [49]. Bromide 157... 

To conclude this section and to provide a bridge to the next, the work of Pal s group on novel phosphodiesterase 4 (PDE4) inhibitors will be discussed [40]. In their paper from 2012, a new multicomponent strategy was described that unites isatoic anhydride 149, aryl hydrazines 150, and 2-iodobenzaldehyde 151. This palladium-catalyzed MCR gratifyingly generates quinazolin-4-ones in acetonitrile under air atmosphere in 24 h at reflux temperatures (Scheme 14.19). 

Although most of the established metal-catalyzed MCRs are based on palladium or copper catalysts, the search for new MCR products has resulted in the development of new catalytic systems in the last decade. This chapter has been... 

Yoshida MCR is a palladium-catalyzed coupling reaction between allenylboronates, secondary amines, and an aryl iodide to give ally lie amines 51 with complete control of the olefin geometry, which could be isolated or used for subsequent reactions (Scheme 4.23) [43],... 

The last category is the class of MCRs catalyzed by organometallic species (MC-MCRs). MC-MCRs include the palladium-catalyzed multicomponent reaction of vinyl compounds [52], the three-component Sakurai allylation reaction [53], metal-catalyzed three-component reactions between alkynes, amines, and... 

Scheme 5 Polymer synthesis based on palladium and rhodium catalyzed MCRs...

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