Molybdenum(II)-Catalyzed Allylation of Electron-Rich Aromatics and Heteroaromatics.
The stable, readily available molybdenum(II) complexes [Mo(CO)(4)Br(2)](2) (B) and Mo(CO)(3)(MeCN)(2)(SnCl(3))Cl (C) have been found to catalyze C-C bond-forming allylic substitution with electron-rich aromatics (e.g., 15 + PhOMe --> 62) and heteroaromatics (e.g., 15 + 36 --> 88) as nucleophiles under mild conditions (room temperature, 30 min-3 h). Remarkable is the para-selectivity for anisole, whereas phenol tends to favor ortho-substitution in certain instances. Mechanistic and stereochemical experiments are indicative of Lewis-acid catalysis rather than a metal template-controlled process.
Malkov
Andrei V.
AV
Department of Chemistry, University of Leicester, Leicester LE1 7RH, U.K., and Receptor Chemistry Unit, GlaxoWellcome PLC, Stevenage, Herts SG1 2NY, U.K.
Davis
Stuart L.
SL
Baxendale
Ian R.
IR
Mitchell
William L.
WL
Kocovský
Pavel
P