Synthesis and recognition of amino acids by binaphthyl-crown receptors

Abstract Two binaphthyl crown receptors containing phenylboric acid 2 and 2,4-dinitrophenylurea 3 as lariat parts were prepared from the optically active binaphthyl crown alcohol 1 in two and four steps, respectively. Host 2 showed a 30% extraction efficiency for GABA by a solid–liquid extraction method in DMSO. Chromogenic Host 3 discriminated the guest linear amino acid by molecular length and the information was revealed through color changes.