Arylation of diethyl malonate and ethyl cyanoacetate catalyzed by palladium/di-tert-butylneopentylphosphine

作者：Semmes Jeffrey G; Bevans Stephanie L; Mullins C Haddon; Shaughnessy Kevin H^*

来源：Tetrahedron Letters, 2015, 56(23): 3447-3450.

DOI：10.1016/j.tetlet.2015.01.072

• Cross-coupling
• Palladium
• Phosphine
• Enolate

alpha-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 beta-dicarbonyl derivatives is significantly more challenging. The ability of beta-dicarbonyl anions to bind to palladium in a kappa(2)-O,O mode, rather than the kappa(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-tert-butylneopentylphosphine (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.

• 出版日期2015-6-3