Fig. 7: Gram-scale reactions and synthetic transformations. | Nature Catalysis

Fig. 7: Gram-scale reactions and synthetic transformations.

From: Facile access to fused 2D/3D rings via intermolecular cascade dearomative [2 + 2] cycloaddition/rearrangement reactions of quinolines with alkenes

Fig. 7

a, Generation of highly decorated quinolines via rearomatization. b, Exploitation of the rearomatization strategy forming a key intermediate towards a CXCR7 receptor antagonist. c, Gram-scale [2 + 2] cycloaddition/rearrangement reaction followed by epoxidation. d, Synthetic elaboration of the pyridine core via oxidation and Reissert–Henze reaction. e, Ester group hydrolysis and X-ray structural determination of 66. a Contains approximately 15% of an inseparable isomeric product. Reaction conditions: (1) Pd(PPh3)4 (5 mol%), PPh3 (10 mol%), tBuOK (2.0 equiv.), iPrOH (0.1 M), 450 nm LEDs, room temperature; (2) morpholine (2.0 equiv.), nBuLi (2.0 equiv.), tetrahydrofuran (THF) (0.4 M), 0 °C then 22 (1.0 equiv.), THF (0.2 M), 0 °C; (3) 1-benzyl-1,4-diazepane (2.0 equiv.), nBuLi (2.0 equiv.), THF (0.4 M), 0 °C then 22 (1.0 equiv.), THF (0.2 M), 0 °C; (4) tBuOK (2.0 equiv.), THF (0.17 M), −40 °C; (5) mCPBA (3.0 equiv.), CH2Cl2 (0.1 M), room temperature; (6) TMSCl (3.0 equiv.), BzCl (2.0 equiv.), CH2Cl2 (0.1 M), 0 °C to room temperature; (7) NaOH (5.0 equiv.), MeOH:H2O (4:1, 0.1 M), 50 °C. For experimental details, see Supplementary Methods. Bn, benzyl; Bz, benzoyl; d.r., diastereomeric ratio; mCPBA, meta-chloroperbenzoic acid; TMS, trimethylsilyl.

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