Addition reactions of conjugated double bonds

Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones

“…20 The compound was obtained from Michael addition of benzylidenehydrazine (20 μL, 0.20 mmol) to tert-butyl acrylate (59 μL, 0.40 mmol), as a yellowish oil (dppe: 38.5 mg, 87%; dppb: 40.1 mg, 91%) after column chromatography on silica gel with hexane:EtOAc = 9:1. 1 (3-(Ethylsulfonyl)propyl)benzene (3c). 20 The compound was obtained from Michael addition of benzylidenehydrazine (20 μL, 0.20 mmol) to ethyl vinyl sulfone (42 μL, 0.40 mmol), as a yellowish oil (dppe: 15.3 mg, 36%; dppb: 31.1 mg, 71%) after column chromatography on silica gel with hexane:Et 2 O = 1:1.…”

“…33 The compound was obtained from Michael addition of benzylidenehydrazine (20 μL, 0.20 mmol) to dimethyl vinylphosphonate (47.5 μL, 0.40 mmol), as a yellowish oil (dppe: 45.4 mg, 99%; dppb: 39.0 mg, 85%) after column chromatography on silica gel with EtOAc. 1 General Procedure B (for 3h−3w Synthesis). A flame-dried Ushaped microwave reaction vial (10 mL) was first charged with mesitylcopper complex solution (0.3 mL).…”

“…35 The compound was obtained from Michael addition of (4-(trifluoromethyl)benzylidene)hydrazine (37.6 mg, 0.20 mmol) to methyl acrylate (36 μL, 0.40 mmol), as a yellowish oil (dppe: 25.1 mg, 51%) after column chromatography on silica gel with hexane:EtOAc = 3:1. 1 H NMR (500 MHz, CDCl 3 , ppm) δ 7.56 (d, J = 8.1 Hz, 2H), 7.32 (d, J = 8.0 Hz, 2H), 3.69 (s, 3H), 2.73 (t, J = 7.7 Hz, 2H), 2.36 (t, J = 7.4 Hz, 2H), 2.00 (quin, J = 7.5 Hz, 2H); 13 C{ 1 H} NMR (125 MHz, CDCl 3 , ppm) δ 173.6, 145.4, 128.7, 128.4 (q, J C,F = 32.1 Hz), 125.3 (q, J C,F = 3.7 Hz), 124.3 (q, J C,F = 121.1 Hz), 51.5, 34.9, 33.2, 26.1; 19 F NMR (471 MHz, CDCl 3 , ppm) δ −62.36; MS (EI) 246.1 (M + ).…”

“…Conjugate addition is one of the basic chemistry tools realizing bond formation between a nucleophile and a molecule having conjugated system such as α,β-unsaturated ketone, nitrile, ester, etc . Copper reagents and catalysts have played the dominant role throughout the history of such reactions, and numerous 1,4-additions mediated and/or catalyzed by copper complexes have been achieved (Scheme , a). − Inspired by the Wolff–Kishner reduction in which hydrazine was employed for the generation of carbanion equivalent from electrophilic aldehydes and ketones, a wide variety of reactions have been developed for the formation of new carbon–carbon bond, via such an umpolung strategy .…”

“…1 H NMR (500 MHz, CDCl 3 , ppm) δ 7.51−7.49 (m, 1H), 7.44−7.42 (m, 1H), 7.26−7.18 (m, 2H), 6.44 (d, J = 0.9 Hz, 1H), 3.70 (s, 3H), 2.86 (td, J = 7.3, 0.6 Hz, 2H), 2.45 (t, J = 7.4 Hz, 2H), 2.12 (quin, J = 7.4 Hz, 2H);13 C{ 1 H} NMR (100 MHz, CDCl 3 , ppm) δ 173.6, 158.1, The Journal of Organic Chemistry pubs.acs.org/joc Note h i b i t e d .…”