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The recognition abilities of chiral calixarene hosts toward alkali cation guests have been exploited for the first time in asymmetric phase-transfer catalysis. The binding affinities of a series of chiral α-methylbenzylamine-derived calix[4]areneamides toward Na+ guest have been determined by ¹H NMR spectroscopic titration experiments. The good apparent association constant values are consistent with the macrocycles' catalytic efficiency in the asymmetric alkylation reaction of N-(diphenylmethylene) glycine esters under phase-transfer conditions. [ABSTRACT FROM AUTHOR]

The TFPB “superweak anion”effectively induces thethreading of a scarcely preorganized calix[6]arene (1) with weakly interacting tertiary ammonium axles (2+–3+). The pseudorotaxanes (4+–5+) thus formed showan unexpected chirality due to an unprecedented formation of a threading-inducedstereogenic ammonium center. [ABSTRACT FROM AUTHOR]