The chemical shift of EtMgBr and Et2Mg as a qualitative measure of the basicity of electron-donating solvents

Added-Metal-Free Catalytic Nucleophilic Addition of Grignard Reagents to Ketones

“…1 H NMR (400 MHz, CDCl 3 ): δ 1.96 (s, 3H), 2.25 (s, 1H), 7.25 (m, 2H), 7.32 (t, J = 7.19 Hz, 4H), 7.42 (m, 4H). 13 C NMR (100 MHz, CDCl 3 ): δ 30.9, 76.2, 125.8, 127.0, 128.2, 148.0.…”

“…General Methods. 1 H NMR (400 MHz) and 13 C NMR (100 MHz) spectra were recorded in CDCl 3 solutions. Chemical shifts are reported in parts per million (ppm, δ) relative to CDCl 3 (δ 7.26 for 1 H NMR) or CDCl 3 (δ 77.1 for 13 C NMR).…”

“…1 H NMR (400 MHz, CDCl 3 ): δ 0.83 (t, J = 7.4 Hz, 3H), 1.58 (s, 3H), 1.77 (s, 1H), 1.87 (m, 2H), 7.24−7.47 (m, 5H). 13 C NMR (100 MHz, CDCl 3 ): δ 8.3, 29.6, 36.7, 74.9, 124.9, 126.5, 128.1, 147.8.…”

“…1 H NMR (400 MHz, CDCl 3 ): δ 1.57 (s, 3H), 2.25 (s, 1H), 2.52 (dd, J = 8.2 Hz, 13.8 Hz, 1H), 2.70 (dd, J = 8.2 Hz, 13.8 Hz, 1H), 5.15 (m, 2H), 5.66 (m, 1H), 7.24−7.48 (m, 5H). 13 C NMR (100 MHz, CDCl 3 ): δ 29.9, 48.5, 73.7, 119.4, 124.8, 126.6, 128.2, 133.8, 147.7.…”

“…It is well-known that the Schlenk equilibrium of Grignard reagents changes the structures of Grignard reagents in solution. − Therefore, an effect that facilitates the shifting of Schlenk equilibrium of Grignard reagents in solution to form dimeric Grignard reagents would favor the addition reaction. In 1970, Chastrette reported that a stoichiometric amount of tetrabutylammonium bromide (NBu 4 Br) could promote the addition reaction of di-isopropyl ketone with n -PrMgBr by forming a Grignard reagent–salt complex .…”