One-step hydroxylation of aryl and heteroaryl fluorides using mechanochemistry

Abstract

Simple use of KOH allows the direct F to OH exchange of aromatic and heteroaromatic substrates under mechanochemical conditions.

Mechanochemical Asymmetric Transfer Hydrogenation of Diketones to Access Chiral 1,3-Diols under Solvent-Free Conditions

“…1 H NMR and 13 C NMR spectra Solid-state NMR experiments were explored on a Bruker AVANCE spectrometer at a magnetic field strength of 9.4 T with 1 H frequency of 400.1 MHz, 13 C frequency of 100.5 MHz. Spectra were calibrated relative to solvent's residual proton and carbon chemical shift: CHCl3 (δ (ppm) = 7.26 ppm for 1H NMR and δ (ppm) = 77.0 ppm for 13C NMR).…”

“…7 White solid, yield 93% (48.9 mg), 92% ee, 93:7 dr; [α] = -54.36; 1 H NMR (400 MHz, DMSO-d6) δ 7.39 -7.23 (m, 8H), 7.20 (t, J = 8.1 Hz, 1H), 4.93 (dd, J = 8.2, 3.9 Hz, 2H), 2.92 (d, J = 83.7 Hz, 2H), 2.18 -2.06 (m, 2H). 13 2e: (1S,3S)-1,3-bis(3-chlorophenyl)propane-1,3-diol. 7 White solid, yield 95% (56.5 mg), 99% ee, 91:9 dr; [α] = -52.36; 1 H NMR (400 MHz, CDCl3) δ 7.22 (d, J = 2.1 Hz, 2H), 7.19 -7.12 (m, 4H), 7.06 (dt, J = 6.7, 2.0 Hz, 2H), 4.78 (t, J = 5.7 Hz, 2H), 3.45 (s, 2H), 1.97 (t, J = 5.8 Hz, 2H).…”

“…7 White solid, yield 95% (56.5 mg), 99% ee, 91:9 dr; [α] = -52.36; 1 H NMR (400 MHz, CDCl3) δ 7.22 (d, J = 2.1 Hz, 2H), 7.19 -7.12 (m, 4H), 7.06 (dt, J = 6.7, 2.0 Hz, 2H), 4.78 (t, J = 5.7 Hz, 2H), 3.45 (s, 2H), 1.97 (t, J = 5.8 Hz, 2H). 13 4: (S)-2-methyl-1,2,3,4-tetrahydroquinoline. 12 Yellow oil, yield 82% (24.1 mg), 47% ee, 96:4 dr; [α] = -53.20; 1 H NMR (400 MHz, DMSO-d6) δ 6.83 (t, J = 6.9 Hz, 2H), 6.46 -6.36 (m, 2H), 5.53 (s, 1H), 3.28 (m, 1H), 2.77 -2.56 (m, 2H), 1.87 -1.78 (m, 1H), 1.41 (m, 1H), 1.13 (d, J = 6.3 Hz, 3H).…”

“…12 Yellow oil, yield 82% (24.1 mg), 47% ee, 96:4 dr; [α] = -53.20; 1 H NMR (400 MHz, DMSO-d6) δ 6.83 (t, J = 6.9 Hz, 2H), 6.46 -6.36 (m, 2H), 5.53 (s, 1H), 3.28 (m, 1H), 2.77 -2.56 (m, 2H), 1.87 -1.78 (m, 1H), 1.41 (m, 1H), 1.13 (d, J = 6.3 Hz, 3H). 13 C NMR (100 MHz, DMSO-d6) δ 145.9 (C), 129.2 (CH), 126.8 (CH), 120.0 (CH), 115.6 (CH), 113.7 (C), 46.6 (CH), 30.2 (CH2), 26.6 (CH2), 22.64 (CH3). HPLC (OJ, elute: Hexane/ i-PrOH = 95/5, detector: 254 nm, flow rate: 0.5 mL / min, 25°C), t1 = 36.9 min (minor), t2 = 40.8 min (major).…”

“…Geneste group has realized the hydroxylation of aryl and heteroaryl fluorides using KOH as base with the assistance of ball milling. 13 Furthermore, mechanochemistry also allows for the…”