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The large-scale applications of the kinetic resolution of urethane-protected α-amino acid N-carboxyanhydrides (UNCAs) and the desymmetrization of cyclic meso-anhydrides using modified cinchona alkaloids are described. These asymmetric reactions are effective organocatalytic methods for the synthesis of chiral α-amino acids 6 and chiral half-esters 2 on an industrial scale, because the organocatalyst recovery and product purification can be carried out by a simple extractive procedure obviating a chromatographic purification step. The modified cinchona alkaloid catalysts (DHQD)2AQN and (DHQ)2AQN, as reported by Deng and co-workers, are not readily available and therefore not suitable for industrial-scale synthesis. Various O-alkylated quinidine and quinine derivatives were prepared and screened as catalysts for the kinetic resolution of phenylalanine UNCA with alcohol. The readily prepared O-propargylquinidine (OPQD) and O-propargylquinine (OPQ) were discovered to be highly enantioselective and practical catalysts. These new catalysts were applied to the synthesis of chiral propargylglycine 24 and the key intermediate of BAY10-8888/PLD-118, 26, on an industrial scale, by the kinetic resolution of UNCA 22 and the desymmetrization of cyclic meso-anhydride 25, respectively.

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Light as a reagent: A highly functionalized structure that serves as a daphnane template can be formed by the photorearrangement of a 2,5‐cyclohexadienone subunit within a complex tricyclic ring system (see scheme). The chemistry we describe should not only find use in the total synthesis of resiniferatoxin and related daphnanes, but should also provide useful templates for access to complex analogues.

Polymers containing sugar units in the main chain were synthesized by polycondensation of diboronic acid and C2-symmetrical chiral tetrols. Spectroscopic studies and theoretical calculations established that they possess a DNA-like helical structure.