Recyclable heterogeneous gold(I)-catalyzed oxidation of internal acylalkynes: Practical access to vicinal tricarbonyls

Copper-Catalyzed Aerobic C(<i>sp</i>³)–H Oxidation of β-(Alkoxy)imino Carbonyl Compounds

“…Methyl (E/Z)-3-((O-Phenylmethoxy)imino)butanoate (1a) Following to the general procedure A using methyl acetoacetate (5.0 g, 43 mmol), O-benzylhydroxylamine hydrochloride (8.3 g, 52 mmol), sodium acetate (4.2 g, 52 mmol) and MeOH (50 mL), 1a (9.5 g, 99%) was obtained after purification by flash column chromatography; 1 : 1 mixture of geometric isomers as a colorless oil; IR (neat): 2953, 1742 cm Methyl (E/Z)-3-((Benzyloxy)imino)pentanoate (1e) Following to the general procedure A using methyl 3-oxopentanoate (0.50 g, 3.8 mmol), O-benzylhydroxylamine hydrochloride (0.74 g, 4.6 mmol), sodium acetate (0.38 g, 4.6 mmol) and MeOH (7.7 mL), 1e (0.75 g, 83%) was obtained after purification by flash column chromatography; 7 : 3 mixture of geometric isomers as a colorless oil; IR (neat): 2953, 1744 cm −1 ; 1 H-NMR (400 MHz, CDCl 3 ) δ: 7.35-7.27 (m, 5H), 5.09 (s, 14/10H), 5.08 (s, 6/10H), 3.68 (s, 9/10H), 3.61 (s, 21/10H), 3.32 (s, 14/10H), 3.22 (s, 6/10H), 2.45 (q, J = 7.6 Hz, 6/10H), 2.30 (q, J = 7.6 Hz, 14/10H), 1.10 (t, J = 7.6 Hz, 21/10H), 1.05 (t, J = 7.6 Hz, 9/10H); 13 Methyl…”

“…Following to the general procedure A using methyl 3-cyclopropyl-3-oxopropanoate (1.0 g, 7.03 mmol), O-benzylhydroxylamine hydrochloride (1.3 g, 8.44 mmol), sodium acetate (0.69 g, 8.44 mmol) and MeOH (10 mL), 1f (0.66 g, 38%) was obtained after purification by flash column chromatography; 10 : 1 mixture of geometric isomers as a colorless oil; IR (neat): 1742 cm −1 ; 1 H-NMR (300 MHz, CDCl 3 ) δ: 7.39-7.29 (m, 5H), 5.14 (s, 2H), 3.69 (s 3H), 2.92 (s, 2H), 2.40-2.30 (m, 1H), 0.89-0.68 (m, 4H); 13 Following to the general procedure A using 1,5-dimethyl 3-oxopentanedioate (0.50 g, 2.9 mmol), O-benzylhydroxylamine hydrochloride (0.55 g, 3.4 mmol), sodium acetate (0.28 g, 3.4 mmol) and MeOH (5.7 mL), 1g (0.79 g, 99%) was obtained as a single isomer after purification by flash column chromatography. The E/Z geometry was not determined; an colorless oil; IR (neat): 2955, 1743 cm −1 ; 1 H-NMR (400 MHz, CDCl 3 ) δ: 7.35-7.28 (m, 5H), 5.11 (s, 2H), 3.68 (s, 3H), 3.63 (s, 3H), 3.53 (s, 2H), 3.40 (s, 2H); 13 Methyl 3-((Benzyloxy)imino)-3-phenylpropanoate (1h) Following to the general procedure A using methyl 3-oxo-3-phenylpropanoate (1.78 g, 10.0 mmol), O-benzylhydroxylamine hydrochloride (1.9 g, 12.0 mmol), sodium acetate (0.98 g, 12.0 mmol) and MeOH (20.0 mL), 1h (1.6 g, 56%) was obtained as a single isomer after purification by flash column chromatography.…”

“…Following to the general procedure A using methyl 3-cyclopropyl-3-oxopropanoate (1.0 g, 7.03 mmol), O-benzylhydroxylamine hydrochloride (1.3 g, 8.44 mmol), sodium acetate (0.69 g, 8.44 mmol) and MeOH (10 mL), 1f (0.66 g, 38%) was obtained after purification by flash column chromatography; 10 : 1 mixture of geometric isomers as a colorless oil; IR (neat): 1742 cm −1 ; 1 H-NMR (300 MHz, CDCl 3 ) δ: 7.39-7.29 (m, 5H), 5.14 (s, 2H), 3.69 (s 3H), 2.92 (s, 2H), 2.40-2.30 (m, 1H), 0.89-0.68 (m, 4H); 13 Following to the general procedure A using 1,5-dimethyl 3-oxopentanedioate (0.50 g, 2.9 mmol), O-benzylhydroxylamine hydrochloride (0.55 g, 3.4 mmol), sodium acetate (0.28 g, 3.4 mmol) and MeOH (5.7 mL), 1g (0.79 g, 99%) was obtained as a single isomer after purification by flash column chromatography. The E/Z geometry was not determined; an colorless oil; IR (neat): 2955, 1743 cm −1 ; 1 H-NMR (400 MHz, CDCl 3 ) δ: 7.35-7.28 (m, 5H), 5.11 (s, 2H), 3.68 (s, 3H), 3.63 (s, 3H), 3.53 (s, 2H), 3.40 (s, 2H); 13 Methyl 3-((Benzyloxy)imino)-3-phenylpropanoate (1h) Following to the general procedure A using methyl 3-oxo-3-phenylpropanoate (1.78 g, 10.0 mmol), O-benzylhydroxylamine hydrochloride (1.9 g, 12.0 mmol), sodium acetate (0.98 g, 12.0 mmol) and MeOH (20.0 mL), 1h (1.6 g, 56%) was obtained as a single isomer after purification by flash column chromatography. The E/Z geometry was not determined; an colorless oil; IR (neat): 1741 cm −1 ; 1 H-NMR (300 MHz, CDCl 3 ) δ: 7.66-7.61 (m, 2H) 7.41-7.30 (m, 8H), 5.27 (s, 2H), 3.80 (s, 2H), 3.63 (s, 3H); 13 Following to the general procedure A using ethyl 3-(4-nitrophenyl)-3-oxopropanoate (0.70 g, 3.0 mmol), O-benzylhydroxylamine hydrochloride (0.56 g, 3.5 mmol), sodium acetate (0.29 g, 3.5 mmol) and EtOH (10 mL), 1m (1.0 g, 98%) was obtained after purification by flash column chromatography; 5 : 1 mixture of geometric isomers as a colorless oil; IR (neat): 2983, 1737, 1520, 1347 cm −1 ; 1 H-NMR (400 MHz, CDCl 3 ) δ: 8.24-8.22 (m, 2H), 7.82-7.80 (m, 10/6H), 7.64-7.62 (m, 2/6H), 7.42-7.38 (m, 5H), 5.31 (s, 10/6H), 5.15 (s, 2/6H), 4.11 (q, J = 7.2 Hz, 10/6H), 4.09 (q, J = 7.2 Hz, 2/6H), 3.82 (s, 10/6H), 3.61 (s, 2/6H), 1.172 (t, J = 7.2 Hz, 15/6H), 1.165 (t, J = 7.2 Hz, 3/6H),; 13 Following to the general procedure A using methyl 3-oxo-3-(thiophen-2-yl) propanoate (1.84 g, 10 mmol), O-benzylhydroxylamine hydrochloride (1.9 g, 12 mmol), sodium acetate (0.98 g, 12 mmol) and MeOH (20 mL), 1r (2.42 g, 84%) was obtained after purification by MCC; 2 : 1 mixture of geometric isomers as a colorless oil; IR (neat): 1742 cm −1 ; 1 H-NMR (400 MHz, CDCl 3 ) δ: 7.49-7.48 (m, 1/3H), 7.45-7.42 (m, 2/3H), 7.40-7.24 (m, 5H + 1/3H), 7.19-7.17 (m, 2/3H), 7.04 (dd, J = 4.9, 4.2 Hz, 1/3H), 6.98 (dd, J = 5.1, 3.5 Hz, 2/3H), 5.33 (s, 2/3H), 5.21 (s, 4/3H), 3.75 (s, 4/3H), 3.69 (s, 2/3H), 3.66 (s, 3/3H), 3.60 (s, 6/3H); 13 Following to the general procedure A using methyl 4,4-dimethyl-3-oxopentanoate (0.50 g, 3.16 mmol), O-benzylhydroxylamine hydrochloride (0.60 g, 3.79 mmol), sodium acetate (0.31 g, 3.79 mmol) and MeOH (6.3 mL), 1s (0.83 g, 99%) was obtained as a single isomer after purification by MCC.…”

“…[3][4][5] In addition, imine derivatives of VTCs exist not only in biologically active compounds, such as fungicides 6) and pesticides, 7) but are also used as synthetic intermediates for antibiotics, 8) anticancer agents, 9,10) and CRF-1 antagonists 11) as well as functionalized polymers. 12) In contrast to the diversity of approaches published for the preparation of VTCs, 1,2,[13][14][15][16][17][18][19][20][21][22][23] the synthesis of VTC imine derivatives is scarcely reported. Direct C(sp 3 )-H oxidation of readily available β-imino carbonyl compounds, such as 3-iminobutanoates, represents the most convenient method for accessing 1-imino-2,3-dicarbonyl compounds.…”

Enhanced Catalysis Based on the Surface Environment of the Silica-Supported Metal Complex

“…The supported Au catalyst could be reused at least 11 times without any enantioselectivity loss, whereas the Au amount gradually decreased. Other silica-supported Au­(I) complex catalysts have also been applied using directly attached phosphine ligands with methylene linkers. − …”