An Improved Protocol for the Pd-Catalyzed r-Arylation of Aldehydes with Aryl Halides

Reaction Scheme

Abstract

A series of palladacyclic precatalysts that incorporate electron-rich di-tert-butylphosphino biaryl ligands is reported. These precatalysts are easily prepared, and their use provides a general means of employing bulky ligands in palladium-catalyzed cross-coupling reactions. The application of these palladium sources to various C-N and C-O bond-forming processes is also described.

Substrates

Procedure

ALKYL ALCOHOL ARYLATUON: A screw-top test tube equipped with a magnetic stir bar and fitted with a Teflon septum was charged with aryl halide (1.00 mmol, 1.00 equiv), alcohol (if a solid) (1.50 mmol, 1.50 equiv), Cs2CO3 (652 mg, 2.00 mmol, 2.00 equiv) and RockPhos-Pd-G3 (1 � 2 mol %). The tube was sealed and evacuated and backfilled with argon. This sequence was repeated a total of three times, after which the aryl halide and alcohol, if liquids, were added by syringe, followed by toluene (1 mL) by syringe. The reaction mixture was stirred at 90 �C for 16 � 24 h. After completion the reaction mixture was cooled to room temperature, diluted with ethyl acetate (5 mL) and filtered. The crude reaction mixture was concentrated with the aid of rotary evaporation and purified by flash chromatography.

Products

Materials

     
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