Di‐tert‐butylneopentylphosphine (DTBNpP) and palladium(II) acetate provide an efficient catalytic system for the α‐arylation of ketones. Aryl bromides were coupled with ketones using 0.25–0.5 mol‐% Pd(OAc)2/DTBNpP in toluene at 50 °C, whereas aryl chlorides required a higher catalyst loading (0.5–2.0 mol‐%) and a higher temperature (80 °C). Coupling of 2‐bromophenol with ketones using the Pd/DTBNpP system provides an efficient route for the synthesis of benzofurans.

EtO OEt O O EtO OEt O O Pd(dba) 2 t-Bu 2 P t-Bu Ar EtO CN O Ar ArX EtO CN O Base Br: 20 examples Cl: 8 examples Br: 7 examples © 2015. This manuscript version is made available under the Elsevier user licenseAbstract α-Arylated carbonyl derivatives are important structural motifs in many natural products and pharmaceutically active compounds. Although arylation of simple monocarbonyl compounds is a well-established methodology, metal-catalyzed arylation of β-dicarbonyl derivatives is significantly more challenging. The ability ofβ-dicarbonyl anions to bind to palladium in a κ 2 -O,O mode, rather than the κ 1 -C-bound mode required for bond formation, often results in the deactivation of catalyst systems. The C-bound form of the enolate can be favored through the use of sterically demanding ligands. Herein, we report that the sterically demanding di-tertbutylneopentylphosphine (DTBNpP) ligand in combination with Pd(dba) 2 provides an effective catalyst for the coupling of aryl bromides and chlorides with diethyl malonate. The Pd/DTBNpP system also catalyzes the coupling of aryl bromides with ethyl cyanoacetate.

Di-tert-butylneopentylphosphine (DTBNpP): An Efficient Ligand in the Palladium-Catalyzed -Arylation of Ketones. -(RADERS, S. M.; JONES, J. M.; SEMMES, J. G.; KELLEY, S. P.; ROGERS, R. D.; SHAUGHNESSY*, K. H.; Eur. J. Org. Chem. 2014, 33, 7395-7404, http://dx.

Arylation of Diethyl Malonate and Ethyl Cyanoacetate Catalyzed by Palladium/ Di-tert-Butylneopentylphosphine. -It is demonstrated, that the title catalyst system renders possible the efficient arylation of substrates (I) and (V) with a wide variety of aryl bromides and chlorides. -(SEMMES, J. G.; BEVANS, S. L.; MULLINS, C. H.; SHAUGHNESSY*, K. H.; Tetrahedron Lett. 56 (2015) 23, 3447-3450, http://dx.