LiHMDS‐Mediated Deprotonative Coupling of Toluenes with Ketones. Issue 15 (13th February 2023) - Shigeno, Masanori
Abstract: We demonstrate that lithium hexamethyldisilazide (LiHMDS) acts as an effective base for deprotonative coupling reactions of toluenes with ketones to afford stilbenes. Various functionalities (halogen, OCF3, amide, Me, aryl, alkenyl, alkynyl, SMe, and SPh) are allowed on the toluenes. Notably, this system proved successful with low‐reactive toluenes bearing a large pKa value compared to that of the conjugate acid of LiHMDS (hexamethyldisilazane, 25.8, THF), as demonstrated by 4‐phenyltoluene (38.57, THF) and toluene itself (∼43, DMSO). Abstract : Lithium hexamethyldisilazide (LiHMDS) acts as an effective base for deprotonative coupling reactions of toluenes with ketones. Various functionalities are allowed on the toluenes. Notably, this system proved successful with low‐reactive toluenes bearing a large pKa value compared to that of the conjugate acid of LiHMDS (hexamethyldisilazane, 25.8, THF), as demonstrated by 4‐phenyltoluene (38.57, THF) and toluene itself (∼43, DMSO).