Catalytic electronic activation as a tool for the addition of stabilised nucleophiles to allylic alcohols

Highly enantioselective Michael addition of malononitrile to α,β-unsaturated ketones

“…3), was obtained in 30% yield with 90% ee (entry 11), which may be derived from the desired adduct 4k and malononitrile. 13 Gratifyingly, reaction of chalcone 3l, which was inert with vinylogous donors, 10a proceeded smoothly to give the desired adduct 4l with 88% ee despite the longer time required (entry 12). As aromatic ketones (R 1 = R 2 = Ar) might be unfavorable for the formation of iminium ions with amine catalysts, the Michael addition of chalcone analogues with amine as catalyst has rarely been reported.…”

“…As aromatic ketones (R 1 = R 2 = Ar) might be unfavorable for the formation of iminium ions with amine catalysts, the Michael addition of chalcone analogues with amine as catalyst has rarely been reported. 10g It turned out that the substituents on the phenyl group of chalcone had a large influence on the yields and 3m, 3n and 3o gave ≤40% yield with ≥83% ee (entries [13][14][15]. It is notable that higher yields were achieved at elevated temperature, yet the enantioselectivities only slightly decreased.…”

“…1 H-NMR (CDCl 3 , 300 MHz) 4H),4.45 (d,J = 5.3 Hz,1H), 3.73-3.67 (m, 1H), 3.21-3.02 (m, 2H), 2.36 (s, 3H), 2.20 (s, 3H) ppm. 13 C-NMR (CDCl 3 , 75 MHz) d 205. 4, 139.1, 133.2, 129.9, 127.6, 111.8, 111.6, 44.8, 40.5, 30.3, 28.7, 21.1 ppm.…”

“…(d,J = 8.7 Hz,2H),6.92 (d,J = 8.7 Hz,2H),4.44 (d,J = 5.3 Hz,1H), 3.81 (s, 3H), 3.72-3.68 (m, 1H), 3.21-3.00 (m, 2H), 2.21 (s, 3H) ppm. 13 C-NMR (CDCl 3 , 75 MHz) d 205. 4, 160.2, 129.0, 128.1, 114.6, 111.8, 111.6, 55.3, 44.9, 40.2, 30.3, 28.8 2H),2H),4.47 (d,J = 5.3 Hz,1H), 3.76-3.69 (m, 1H), 3.21-3.01 (m, 2H), 2.23 (s, 3H) ppm.…”

Metal-dioxidoterephthalate MOFs of the MOF-74 type: Microporous basic catalysts with well-defined active sites

“…According to literature, the nature of the catalyst strongly influences whether a Knoevenagel or a Michael addition reaction takes place. Whereas Lewis acids such as RuCl 3 or Ruexchanged hydroxyapatite are reported to selectively catalyze the Knoevenagel condensation, [58] bases like 1,1,3,3-tetramethylguanidine [59] or t-BuOK [60] are reported to catalyze the Michael addition reaction of these compounds. Use of Ni 2 dobdc as a catalyst resulted in the formation of both the Michael addition and the Knoevenagel condensation products (Table 4).…”