Fig. 6: Synthetic applications of iron-catalyzed methylzincation of terminal alkynes.
From: Iron-catalyzed alkyne alkylzincation affected by counterions
a Synthesis of industrially relevant E-Olefins. b Formal synthesis of naucleamides E. Reaction conditions: (i) alkyne 9 (1.0 mmol, 1.0 equiv), C3 (2 mol%), NaBArF4 (5 mol%), Me2Zn (1.1 equiv), toluene, -78 °C to 0 °C, 3 h; (ii) CuCN (3.0 equiv), LiCl (3.0 equiv), methyl propiolate (3.0 equiv), -70 °C, 12 h; (iii) Compound 10 (1.0 equiv), DIBAL-H (3.0 equiv), DCM, −78 °C to 0 °C, 3 h, then MnO2 (5.0 equiv), DCM, 25 °C, 12 h; c Fromal synthesis of (+)-cornexistin and mavacuran alkaloids. (iv) alkyne 12 (0.5 mmol, 1.0 equiv), C3 (2 mol%), NaBArF4 (5 mol%), Me2Zn (1.1 equiv), toluene, -78 °C to -40 °C, 2 h; (v) I2 (3.0 equiv), toluene/THF, rt (~30 °C), 3 h.
