Fig. 2: Scope of single-atom transmutation of epoxides with fluoroalkyl N-triftosylhydrazones.
From: Silver-catalyzed direct conversion of epoxides into cyclopropanes using N-triftosylhydrazones
a Scope of epoxides. b Scope of N-triftosylhydrazones. c Gram-scale synthesis. Reaction conditions: a1 (0.15 mmol, 1.0 equiv.), 2 (0.6 mmol, 4.0 equiv.), NaH (0.68 mmol, 4.5 equiv.) and TpBr3Ag(thf) (10 mol%) in DCM (4.0 mL) at 60 °C for 6–12 h. bExtend reaction time to 24 h. cUsing 6.0 equiv. of 2. d1 (0.15 mmol, 1.0 equiv.), 2 (0.38 mmol, 2.5 equiv.), NaH (0.38 mmol, 2.5 equiv.) and TpBr3Ag(thf) (2.5–5 mol%) in DCM (4.0 mL) at 60 °C for 0.5–6 h. e1 (0.15 mmol, 1.0 equiv.), 2 (0.45 mmol, 3.0 equiv.), NaH (0.45 mmol, 3.0 equiv.) and TpBr3Ag(thf) (5 mol%) in DCM (4.0 mL) at 60 °C for 10 h. f1b (1.2 g, 10 mmol), 2a (9.9 g, 25 mmol), NaH (1.0 g, 25 mmol) and TpBr3Ag(thf) (219 mg, 2 mol%) in DCM (80.0 mL) at 60 °C for 2 h. Yields of the isolated product are given. Diastereomeric ratio (d.r.) determination by relative integration of 19F NMR spectra. PCP, 4-chlorophenyl. PMP, 4-methoxyphenyl.
