A pear-shaped flask was charged with Pd(OAc)2 (2.1 mg, 0.0093 mmol) and 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (8.1 mg, 0.014 mmol) and purged with nitrogen. To the flask was added (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine (19 mg, 0.11 mmol), tert-butyl 5-chlorospiro[indoline-3,4′-piperidine]-1′-carboxylate (30 mg, 0.093 mmol), Cs2CO3 (45 mg, 0.14 mmol) and toluene (0.9 mL). The mixture was heated at about 100° C. for 4 hours. After cooling to about room temperature, the reaction was diluted with EtOAc, filtered through CELITE® (Celite Corp., Santa Barbara, Calif.), and concentrated. The crude product was purified by column chromatography (hexanes:EtOAc, 5:1 to 3:1) to give (R)-tert-butyl 5-chloro-1-(5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)spiro[indoline-3,4′-piperidine]-1′-carboxylate as an oil (30 mg, 71%). LCMS (APCI+) m/z 455, 457 [M+H]+; Rt=4.14 min.
