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PKS biocatalysis: The terminal module of erythromycin synthase was used for the in vitro production of chiral triketide lactones. Combining cofactor regeneration, substrate truncation, and enzymatic promiscuity afforded a scalable strategy to generate these molecules from abundant racemic and achiral precursors. The described biocatalytic platform thus facilitates the application and study of enzymes within PKS modules.

Readily prepared 2-arylacetic anhydrides act as convenient ammonium enolate precursors in isothiourea (HBTM-2.1)-mediated catalytic asymmetric intermolecular Michael addition-lactonisation processes, giving diverse synthetic building blocks in good yield with high diastereo -and enantiocontrol (up to 95:5 dr and >99% ee).

Treatment of orthobenzyloxyphenyloxazolines with butyllithium and potassium t-butoxide results in cyclisation with ring-opening of the oxazoline to give 2-aryl-3-aminobenzofurans. The reaction also occurs with the corresponding benzylthio-and benzylamino-compounds to give benzothiophenes and indoles, respectively. Use of an ortho-allyloxyphenyloxazoline gives the corresponding 2-vinylbenzofuran, while both α-methylbenzyloxy and benzylsulfonyl compounds form stable spirooxazolidine products. The X-ray structure of an aminobenzothiophene product has been determined.

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