Direct N-Alkylation Of Amines

Alkylated amines are versatile building blocks used across the chemistry landscape, and over the years chemists have developed an array of synthesis methods to make them. One well-established approach is the direct reductive amination of carbonyl compounds such as aldehydes or ketones. Iván Sorribes, Kathrin Junge, and Matthias Beller of Leibniz Institute for Catalysis at the University of Rostock, in Germany, now report the first catalytic N-alkylation of amines using more stable and more readily available carboxylic acids (J. Am. Chem. Soc. 2014, DOI: 10.1021/ja5093612). The researchers carried out the platinum-catalyzed reactions using a variety of primary and secondary amines and carboxylic acids with phenylsilane as the hydride reducing agent. The team showed the versatility of the approach by preparing fluoroalkyl-substituted anilines (one shown). The researchers also report the first one-pot catalytic synthesis of cinacalcet hydrochloride, an alkylamine-based drug for treating hyperparathyroidism associated with kidney disease and hypercalcemia associated with parathyroid cancer.