Magnesium-mediated three-component reductive cross-couplings of aryl aldehydes, aryl bromides, and aryl 2-pyridyl esters: An efficient synthesis of diarylmethanol esters

Magnesium was found to be capable of efficiently mediating the one-pot reductive cross-couplings of aryl aldehydes, aryl bromides, and pyridin-2-yl benzoates under transition metal-free conditions. The three-component reactions proceeded well at room temperature in THF in the presence of LiCl, enabling a chemoselective delivery of a large library of diarylmethanol esters in moderate to good yields with broad functionality compatibility. Apart from aryl substituted substrates which served as efficient electrophiles for the present protocol, alkyl substituted starting materials could be amenable to the reaction as well. In addition, the synthetic potency of the method is demonstrated through the scale-up synthesis and the late-stage derivatization of biologically active molecules. The method, which employed readily available starting materials and eliminated the utilization of sensitive and poorly available organometallic reagents, features simple manipulation and step-economy, potentially serving as an appealing alternative to existing methods for the access to diarylmethanol esters.