tert-Butyl 2-cyanopiperidine-1-carboxylate

Description

Tert-Butyl 2-cyanopiperidine-1-carboxylate is an enantioselective organometallic compound. It is a nitrile that reacts with electrophiles such as Grignard reagents and cyano to form an anion. This compound has two chiral centers, each of which can assume either the R or S configuration. The enantiomeric purity of tert-butyl 2-cyanopiperidine-1-carboxylate is greater than 99%. This compound has a low melting point and a half life of about 10 h in water, which makes it stable for use in organic synthesis. It is commonly used in science as a chiral auxiliary in asymmetric synthesis and as a catalyst for the conversion of epoxides to alcohols.

Synthesis

Acetonitrile (220 mL) and DMF (3.82 mL, 49.4 mmol) were added to a 500 mL round bottom flask equipped with a stir bar. Cooled the mixture down to -5 °C and added oxalyl chloride (24.7 mL, 49.4 mmol, 2 M dichloromethane). The resulting mixture was stirred for 15 min, followed by the addition of a solution of 2-carbamoyl-piperidine-1- carboxylic acid tert-butyl ester (9.4 g, 41.2 mmol) in acetonitrile (50 mL) and pyridine (8.3 mL, 103 mmol). The reaction mixture was left stirring at room temperature overnight. The reaction mixture was concentrated in vacuo and the residue was dissolved in ethyl acetate (300 mL). The organic phase was successively washed with water (300 mL) and brine (200 mL), dried (sodium sulfate), filtered, and concentrated in vacuo to isolate tert-Butyl 2-cyanopiperidine-1-carboxylate (8.44 g, 97percent) as a yellow solid.