Fig. 2: Substrate scopes towards nucleophilic aromatization of isoprene.
From: Nucleophilic aromatization of monoterpenes from isoprene under nickel/iodine cascade catalysis
Conditions: Step I: 2a (1.2 mmol), Ni(cod)2/IPr·HCl (5.0 mol%), NaOtBu (10 mol%), n-hexane (0.50 mL), 100 oC, 12 h; Step II: 1 (0.20 mmol), I2 (20 mol%), KI/(PhO)2PO2H (10 mol%), Na2S2O8 (2.0 equiv.), THF (0.50 mL), 100 oC, 24 h. Isolated yields were given in all cases. Regio-selectivities were determined by 1H NMR analysis. a1a (8.0 mmol), 2a (48 mmol), n-hexane/THF (25 + 25 mL), 48 h for the second step; b48 h for the second step; c80 oC for the second step; d1aa (0.10 mmol); eFiltration was required after the first step.
