Oxygen → Methyl 3-cyclopentyl-3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]propanoate

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Reaction Steps

General screening procedure for asymmetric hydrogenation using the substrate, (E)-methyl 3-cyclopentyl-3-(4-(7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)acrylate (21), to afford optically enriched product, methyl 3-cyclopentyl-3-(4-(7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)propanoate ((R)-22 or (S)-22): A 300 mL-volume autoclave with glass vial (20 mL) was charged with the substrate (21), the catalyst (metal, ligand, and catalyst precursor), and oxygen-free solvent (4-6 mL) under nitrogen. This autoclave was charged with hydrogen gas to the desired pressure and stirred at room temperature or heated with oil bath. After hydrogen gas was released, the reaction mixture was concentrated under reduced pressure. The residue was purified by eluting through a silica gel pad using a mixture of ethyl acetate and methanol (v/v=9/1) to afford product, methyl 3-cyclopentyl-3-(4-(7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)propanoate ((R)-22 or (S)-22), for chemical conversion (HPLC and chiral HPLC), LC/MS and NMR spectroscopy and enantiomeric excess (% ee by chiral HPLC) determination.

Provenance & Evidence