Ethyl Acetate → 2-([1,1'-biphenyl]-4-yl)-8-(((3R,3aR,6R,6aS)-6-((tert-butyldimethylsilyl)oxy)hexahydrofuro[3,2-b]furan-3-yl)oxy)-7-((2-(trimethylsilyl)ethoxy)methyl)-7H-purine

Participants

Reaction Conditions

Reaction Steps

Palladium tetrakistriphenylphosphine (21.3 mg, 0.018 mmol) was added to a stirred suspension of 8-(((3R,3aR,6R,6aS)-6-((tert-butyldimethyl-silyl)oxy)hexahydrofuro[3,2-b]furan-3-yl)oxy)-2-chloro-7-((2-(trimethylsilyl)ethoxy)methyl)-7H-purine (Intermediate 47, 50.0 mg, 0.092 mmol), 4-biphenylboronic acid (27.3 mg, 0.138 mmol), and potassium phosphate tribasic (58.6 mg, 0.276 mmol) in degassed 20% water in dioxane (0.72 mL). The reaction mixture stirred under N2 at 85° C. for 2.5 h, then additional more palladium tetrakistriphenylphosphine (21.3 mg, 0.018 mmol) was added. The reaction mixture heated under N2 at 85° C. for another 3.5 h and then cooled to room temperature. The lower aqueous layer was drawn off and discarded. The remaining reaction mixture was added to EtOAc (25 mL), and filtered. The resulting solids were washed with EtOAc (2×10 mL). The filtrate was evaporated under reduced pressure to give a residue. Flash chromatography of the resulting residue utilizing a 12 g silica RediSep Rf® Gold column and employing a 0-80% EtOAc/hexane gradient afforded the title compound. LC-MS: calculated for C35H48N4O5Si2 660.32 observed m/e: 661.61 (M+H)+ (Rt 1.85/2.0 min).

Provenance & Evidence