Denitrogenative Pd/Cu‐catalyzed Suzuki‐type Cross‐coupling of Aryltrifluoroborates with Arylhydrazine Hydrochlorides in Water under Room Temperature

Abstract

A water‐soluble palladium‐catalyzed Suzuki‐type cross‐coupling of aryltrifluoroborates with arylhydrazide hydrochlorides was efficiently developed under mild and environmentally benign conditions, in water without any ligand. The newly developed Pd/Cu co‐catalyzed denitrogenative reaction gave a range of structurally diverse substituted biaryls with good to excellent yields, in which the byproduct was nitrogen.

Arylzinc Halides by Silver Catalyzed Zinc Insertion into Aryl Iodides

“…4‐Methoxy‐1,1′‐biphenyl (3a): Purification by flash chromatography (SiO 2 , hexane/ethyl acetate, 98:2) afforded the product as a white solid: by using iodobenzene ( 1c ) as acceptor and 4‐methoxyphenylzinc iodide ( 2a ) as donor 549 mg (2.98 mmol, 90 %) were obtained, by using 4‐iodoanisole ( 1a ) as acceptor and phenylzinc iodide ( 2c ) as donor 543 mg (2.95 mmol 89 %) were obtained. The NMR spectroscopic data agree with the literature . 1 H NMR (401 MHz, CDCl 3 ): δ = 7.57 (t, J = 8.5 Hz, 4 H), 7.44 (t, J = 7.6 Hz, 2 H), 7.32 (t, J = 7.3 Hz, 1 H), 7.00 (d, J = 8.7 Hz, 2 H), 3.87 (s, 3 H) ppm.…”

Recent Advances in the Pd‐Catalyzed Coupling of Arylhydrazines and Ammonium Salts via C−N Bond Cleavage

“…Qi and co-workers reported that palladium/copper can be used to co-catalyze denitrogenative cross-coupling reactions of arylhydrazines and potassium aryltrifluoroborates at room temperature (Scheme 7). [19] A wide variety of biaryls could be produced in high yields utilizing this approach, which used 2 mol % CuCl 2 •H 2 O as the co-catalyst and water as the solvent.…”

Arylhydrazines: novel and versatile electrophilic partners in cross-coupling reactions

“…Very recently, Wang and co-workers reported an extension of Pd-catalyzed Suzuki coupling of arylhydrazines to the potassium aryltrifluoroborate coupling partners. 16 Thus, in the presence of only 1 mol% of water-soluble Pd(NH 3 ) 2 Cl 2 as a catalyst, 2 mol% of CuCl 2 ·2H 2 O as a co-catalyst and 1.0 equiv. of K 2 CO 3 as a base in water at room temperature, C–C coupling of (het)aryltrifluoroborates 7 with (het)arylhydrazide hydrochlorides 8 furnished functionalized biaryls 9 in good to excellent yields ( Scheme 4 ).…”