Access to Unprotected β‑Fluoroalkyl β‑Amino Acids and Their α‑Hydroxy Derivatives

Unprotected β-(het)­aryl-β-fluoroalkyl β-amino acids and their α-hydroxy derivatives can be readily obtained using a decarboxylative Mannich-type reaction without protection/deprotection steps. This protocol utilizes lithium hexamethyldisilazide and (het)­arylfluoroalkyl ketones to generate NH-ketimine intermediates. The mild reaction conditions allow the preparation of original fluorinated β-amino acids as useful building blocks in a practical and scalable manner.