methyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole-3-carboxylate synthesis

Yield:1268619-58-4 70%

Reaction Conditions:

with 4,4'-di-tert-butyl-2,2'-bipyridine;(1,5-cyclooctadiene)(methoxy)iridium(I) dimer in cyclohexane at 90; for 5 h;

Steps:

3.1

3.1 Compound Synthesis and Characterization Preparation of methyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole-3-carboxylate To a mixture of methyl-1H-pyrrole-3-carboxylate (5.0 g, 39.9 mmol), bis(pinacolato)diboron (5.37 g, 21.1 mmol), 4,4'-di-tert-butyl-2,2'-bipyridine (0.054 g, 0.20 mmol) and [Ir(OMe)(COD)]₂ (0.067 g, 0.099 mmol) was added cyclohexane (60 mL). The mixture stirred at 90° C. for 5 hours. The mixture was cooled to room temperature and filtered, washing with ample amounts of water and twice with hexanes. The light orange solid was collected and dried in a vacuum oven at 55° C. to afford methyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole-3-carboxylate (6.99 g, 70% yield).

References:

US2011/53905,2011,A1 Location in patent:Page/Page column 59