Intermolecular Keto Ester Couplings

Product TiOr Reducing Agent Solvent yield %) R.  

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Although arylation or alkenylation of active methylene compounds can be carried out using a Cu catalyst, the reaction is sluggish. However, the arylation of malononitrile (390) or cyanoacetate proceeds smoothly in the presence of a base and Pd catalysts [189], Tetracyanoquinodimethane (392) is prepared by the coupling of / -diiodoben-zene with malononitrile (390) to give 391, followed by oxidation [190], Presence of the cyano group seems to be essential for intermolecular reactions. However, the intramolecular arylation of malonates, / -keto esters and /i-diketones proceeds smoothly [191]. The bromoxazole 393 reacts with phenylsulphonylacetonitrile (394)... 

McMurry reactions will be presented in the following order intermolecular, intramolecular, mixed (tandem) couplings of aldehydes and ketones, and finally keto ester, oxoamide, and acetal couplings. All the compounds which serve as illustrations are listed in Tables 6.1-6.10, along with the titanium reagents and solvents used for their preparation and the yields of isolated products where not specified, the reactions were performed at solvent reflux temperature. 

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