Three-component coupling of aryl iodides, allenes, and aldehydes catalyzed by a Co/Cr-hybrid catalyst

Abstract

The cobalt/chromium-catalyzed three-component coupling of aryl iodides, allenes, and aldehydes has been developed to afford multi-substituted homoallylic alcohols in a diastereoselective manner. Control experiments for understanding the reaction mechanism reveal that the cobalt catalyst is involved in the oxidative addition and carbometalation steps in the reaction, whereas the chromium salt generates highly nucleophilic allylchromium intermediates from allylcobalt species, without the loss of stereochemical information, to allow the addition to aldehydes.

Strategies for Carbon Electrophile Addition to Carbonyls and Imines by Cobalt Catalysis

“…Three‐component coupling between aryl iodides, allenes and aldehydes has also been disclosed (Scheme 21). [26] Takaki and co‐workers utilized a Co/Cr dual catalytic system to achieve a highly diastereoselective reaction between these three substrates, whereupon syn ‐homoallylic alcohols were preferentially produced as final products. The optimal ligand was found to be the imminopyridine ligand ( L in Scheme 21) and the choice of solvent proved to be crucial as the reaction proceeded only in acetonitrile.…”