反应详情

Following the General Procedure of Description 15 (Part A), zinc dust (Zn) (392 mg, 6.0 mmol) is activated with elemental iodine (I2) (38 mg, 0.15 mmol, 15 mol-%) and trimethyl silylchloride (MeSiCl, TMSCl) (19 μL, 16 mg, 0.15 mmol, 15 mol-%) in degassed anhydrous N,N-dimethylformamide (DMF) (3 mL). The zinc insertion product is prepared from tert-butyl(3S)-3-(tert-butoxycarbonylamino)-4-iodo-butanoate (6c) (385 mg, 1.0 mmol) in the presence of additional I2 (38 mg, 0.15 mmol, 15 mol-%) and TMSCl (19 μL, 16 mg, 0.15 mmol, 15 mol-%). Following the General Procedure of Description 15 (Part B), the zinc insertion product of (6c) is used in situ to cross couple with commercial 3-iodo-4-methyl-phenol (234 mg, 1.0 mmol) in the presence of tris(benzylideneacetone)dipalladium (Pd2(dba)3) (23 mg, 0.025 mmol, 2.5 mol-%) and tris(o-tolyl)phosphine (P(o-tol)3) (30 mg, 0.10 mmol, 10 mol-%) in anhydrous degassed DMF (3 mL). Filtration, aqueous work-up, and purification by silica gel column chromatography furnish the title compound (19a).

1. customin anhydrous degassed DMF (3 mL)
2. filtrationFiltration, aqueous work-up, and purification by silica gel column chromatography