Chlorobis(2,6,6-trimethylbicyclo(3.1.1)heptan-3-yl)borane → (R)-4-[(4-bromophenyl)-hydroxymethyl]-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of (+)-DIP-chloride™ (6.42 g, 20.0 mmol) in THF (10 mL) at 0° C. was added 4-(4-bromobenzoyl)-piperidine-1-carboxylic acid tert-butyl ester (3.68 g, 10.0 mmol). The mixture was stirred at room temperature for 29 hours to give (R)-4-[(4-bromophenyl)-hydroxymethyl]-piperidine-1-carboxylic acid tert-butyl ester (ee 82% determined by both chiral HPLC and Mosher ester) as a crystalline solid (2.22 g, 54%) following work-up and purification. This material was recrystallized (CH2Cl2/hexane) five times to provide a white solid (1.27 g, 35%) with 95% ee.

Provenance & Evidence