Complementary to proline: An axially chiral amino sulfonamide (S)‐1 was successfully applied as the catalyst to the direct cross‐aldol reaction between two different aldehydes (see scheme; NMP=N‐methylpyrrolidone). This catalyst has the advantage of giving mainly syn products, while proline shows the opposite anti selectivity.

[reaction: see text] A novel binaphthyl-based diamine (R)-2 was designed and synthesized. A protonic acid-(R)-2 salt catalyst has the advantage of exhibiting unprecedented high exo selectivity in the asymmetric Diels-Alder reaction of alpha,beta-unsaturated aldehydes. For instance, the reaction between cinnamaldehyde and cyclopentadiene in the presence of 12 mol % of binaphthyl-based diamine (R)-2 and 10 mol % of p-TsOH.H(2)O in alpha,alpha,alpha-trifluorotoluene at -20 degrees C gave the corresponding exo cycloadduct with 92% ee as a major diastereomer (exo/endo = 13/1).

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[structure: see text] A recyclable fluorous chiral phase-transfer catalyst was synthesized and successfully applied for the catalytic asymmetric synthesis of both natural and unnatural alpha-amino acids. The reaction involves alkylation of a glycine derivative followed by extractive recovery of the chiral phase-transfer catalyst using fluorous solvent.

A binaphthyl-based primary amine (R)- was designed for the Diels-Alder reaction of alpha-substituted alpha,beta-unsaturated aldehydes; in the presence of the TfOH salt of (R)-, the Diels-Alder reaction of alpha-substituted alpha,beta-unsaturated aldehydes with cyclopentadiene proceeded to afford the corresponding cycloadducts having one all-carbon quaternary stereocenter in good yield with good to high stereoselectivity.