Fig. 5: Synthetic applications. | Communications Chemistry

Fig. 5: Synthetic applications.

From: A practical preparation of bicyclic boronates via metal-free heteroatom-directed alkenyl sp2-C‒H borylation

Fig. 5

A. Gram-scale experiment and several transformations: (a) p-Anisaldehyde tosylhydrazone (1.3 equiv), K2CO3 (1.3 equiv), dioxane (2.0 mL), 110 °C, 1.5 h; (b) 4-Bromotoluene (1.2 equiv), Pd(PPh3)4 (5 mol %), THF (2.0 mL), K2CO3 (2.0 equiv, 2.0 M aq), 80 °C, 5 h; (c) 10% Pd/C (10 mol %), H2 6 atm, rt, 1.5 h; (d) Pd(OAc)2 (1.0 equiv), CO, DMSO/MeOH (2.0 mL/1.0 mL), rt, 3.0 h; (e) Cu(OAc)2 (0.2 equiv), Ag2CO3 (3.0 equiv), 1,10-phenanthroline (0.22 equiv), EtOH (2.0 mL), H2O (0.1 mL), in air, 80 °C, 22 h; (f) 30% H2O2 (1.0 mL), 3.0 N NaOH (1.0 mL), THF/EtOH (2.0 mL/0.5 mL), rt, 10 min. B. Synthesis and application of chiral hemiboronic acid catalyst: (g) Trityl bromide (1.0 equiv), Et3N (1.0 equiv), DCM (2.0 mL), 60 °C, 4.0 h. C. Practical synthesis of (±)-QPX772.

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