Synthesis of 2-(N-(9-phenylfluoren-9-yl)amino)-1-indanones by anionic cyclization of phenylalanine-derived oxazolidinones

N-(phenylfluorenyl)-2-amino-1-indanones were synthesized from cyclization of bromophenylalanine oxazolidinones by lithium-bromine exchange followed by intramolecular acylation of the aryllithium intermediate. A nitrogen-protecting group 9-phenylfluoren-9-yl was used to preserve the integrity of the chiral center by preventing deprotonation of the alpha-carbon.