Chemoselective synthesis of tertiary and secondary amines by reductive amination of aldehydes

A simple and efficient catalyst-free chemoselective reductive amination of primary amines and aldehydes to synthesis of tertiary and secondary amines with borane complex was developed. Primary amines are converted into tertiary and secondary amines in one pot reaction under mild condition with good functional group compatibility and It does not require any catalyst to participate in this reaction. The chemoselective control was achieved by switching the steric hindrance of borane complex. The strategy was successfully applied to synthetize Tetracaine (anaesthetic) and the potential mechanism was verified by isotope labeling experiments.

Automated summary

A catalyst-free chemoselective reductive amination using borane complex was developed for the synthesis of tertiary and secondary amines from primary amines and aldehydes. The reaction proceeds under mild conditions with good functional group compatibility and does not require any catalyst. Chemoselective control is achieved by manipulating the steric hindrance of the borane complex. This strategy was successfully applied to the synthesis of the anesthetic Tetracaine, and the potential mechanism was verified through isotope labeling experiments.