Gold(I)-Catalyzed Oxidative Amination of β-Amino-ynones to Quaternary Ammonium-olate Salts: The Benefit of a P,N-Bidentate Ligand

Abstract

A novel P,N-bidentate ligand-assisted gold-catalyzed oxidative amination of β-amino-ynones has been developed, allowing the simple and efficient construction of various quaternary ammonium-olate salts in good to excellent yields. These unprecedented quaternary ammonium-olate salts can be isolated and purified via simple suction filtration. The broad substrate scope, easy purification, easy further transformation, and mild conditions make it a viable alternative for the synthesis of various quaternary ammonium-olate salts.

Oxidative Cyclization of 4-(2-Aminophenyl)-4-oxo-2-phenylbutanenitriles into 2-(3-Oxoindolin-2-ylidene)acetonitriles

“…Yield 70 mg (0.28 mmol, 56%). All physical data were identical to those previously described . The title compound was obtained as a yellow amorphous solid, R f 0.25 (EtOAc/hexane, 1:2).…”

“…All physical data were identical to those previously described. 23 The title compound was obtained as a yellow amorphous solid, R f 0.25 (EtOAc/hexane, 1:2). 1 H NMR (400 MHz, CDCl 3 ) δ 10.76 (s, 1H), 7.83 (dt, J = 8.1, 1.0 Hz, 1H), 7.76–7.72 (m, 2H), 7.61–7.55 (m, 1H), 7.55–7.49 (m, 2H), 7.45 (ddd, J = 8.3, 6.9, 1.2 Hz, 1H), 7.23 (d, J = 8.5 Hz, 1H), 7.12 (t, J = 7.5 Hz, 1H), 3.31 (s, 3H); 13 C{ 1 H} NMR (101 MHz, CDCl 3 ) δ 188.9, 153.8, 140.9, 139.1, 131.9, 129.1, 128.7 (2C), 128.6 (2C), 121.6, 121.3, 120.0, 117.3, 110.9, 33.9; FTIR (film, NaCl, cm –1 ): 1701, 1612, 1494, 1470, 1453, 1427, 1371, 1323, 1294, 1253, 1094; HRMS (ESI TOF) m / z : (M + Na) + calc’d for C 16 H 13 NNaO 2 274.0838; found 274.0834 (1.6 ppm).…”

Gold-Catalyzed Oxidative Cyclization/C–C Bond Cleavage of Ynones with External Nucleophiles: Synthesis of Linear Functionalized N-Tosylamides

“…The resulting highly electrophilic α-oxo gold carbene intermediates (Scheme a) could engage in a wide range of transformations such as X–H (X = C, N, O, S) insertions, 1,2-migrations, cyclopropanations, ring expansions, and skeletal rearrangements, etc . During our work on gold-catalyzed reactions involving gold carbenes, we found that difunctionalized gold carbenes such as α,α′-dioxo gold carbenes , derived from ynones or related compounds exhibit more diverse and unique reactivities since both of the two keto groups and the gold-carbene moiety can serve as an electrophilic center. For example, we found that the nucleophilic attack to the keto group of the α,α′-dioxo-gold carbene instead of the carbene center occurred in gold-catalyzed cascade reactions of diynones with alcohols or water .…”