New developments in the synthesis, resolution, and synthetic applications of chiral 1-phenylethylamine (α-PEA) reported in the last decade have been reviewed. In particular, improvements in the synthesis of α-PEA and its derivatives and chiral resolution, as well as their applications in the resolution of other compounds, were discussed. α-PEA was used as a chiral auxiliary in the diastereoselective synthesis of medicinal substances and natural products. Chiral ligands with α-PEA moieties were applied in asymmetric reactions, and effective modular chiral organocatalysts were constructed with α-PEA fragments and used in important synthetic reactions.

New epoxides, derivatives of pyridine, 2,2′-bipyridine, and 1,10-phenanthroline, were synthesized from the respective α-methylazaarenes. The obtained racemic 2-oxiranyl-azaarenes along with styrene oxide and trans-stilbene oxide were submitted to the ring opening with chiral primary amines as a chiral auxiliary. The most effective reaction was run in the presence of Sc(OTf)3/diisopropylethylamine for 7 days at 80°C, affording a good yield of the amino alcohols. Except for styrene oxide which gave both α- and β-amino alcohols, the reactions led regioselectively to the corresponding diastereomeric β-amino alcohols. The resulting diastereomers were separated, and the configurations of their stereogenic centers were established. The obtained enantiomerically pure 2-pyridinyl- and 6-(2,2′-bipyridinyl)-β-amino alcohols were tentatively tested as chiral ligands in the zinc-catalyzed aldol reaction.

Although many chiral ligands for asymmetric catalysis have been developed, there is still a need for new structures allowing the modular approach. Recently, easy synthesis of chiral pyridine-containing β-amino alcohols has been elaborated by opening respective epoxides with enantiomeric 1-phenylethylamine. This paper reports the synthetic transformation of β-amino alcohols into the new complexing pyridine-containing seleno- and thioethers. The amino alcohols were effectively converted to cyclic sulfonamidates, which were reacted with thiolates or phenyl selenide nucleophile. The reaction was diastereoselective, and its outcome depended on the configuration at the substitution center. The problem was discussed considering DFT optimized structures of both diastereomeric sulfonamidates. New amino-aldimine ligands were also synthesized from chiral pyridine-containing diamines. Nine new chiral ligands were tested in the Tsuji-Trost allylic alkylation resulting in the enantiomerically enriched product in up to 75% ee. The observed stereochemical induction agrees with the prevailing nucleophilic attack at the allylic carbon laying opposite to the complexing nitrogen of pyridine in η3-allylic intermediate complexes.