From the enediyne class of antitumor antibiotics, uncialamycin is among the rarest and most potent, yet one of the structurally simpler, making it attractive for chemical synthesis and potential applications in biology and medicine. In this article we describe a streamlined and practical enantioselective total synthesis of uncialamycin that is amenable to the synthesis of novel analogues and renders the natural product readily available for biological and drug development studies. Starting from hydroxy- or methoxyisatin, the synthesis features a Noyori enantioselective reduction, a Yamaguchi acetylide-pyridinium coupling, a stereoselective acetylide-aldehyde cyclization, and a newly developed annulation reaction that allows efficient coupling of a cyanophthalide and a p-methoxy semiquinone aminal to forge the anthraquinone moiety of the molecule. Overall, the developed streamlined synthesis proceeds in 22 linear steps (14 chromatographic separations) and 11% overall yield. The developed synthetic strategies and technologies were applied to the synthesis of a series of designed uncialamycin analogues equipped with suitable functional groups for conjugation to antibodies and other delivery systems. Biological evaluation of a select number of these analogues led to the identification of compounds with low picomolar potencies against certain cancer cell lines. These compounds and others like them may serve as powerful payloads for the development of antibody drug conjugates (ADCs) intended for personalized targeted cancer therapy.

The total synthesis of the spliceosome inhibitor thailanstatin A has been achieved in a longest linear sequence of nine steps from readily available starting materials. A key feature of the developed synthetic strategy is the implementation of a unique, biomimetic asymmetric intramolecular oxa-Michael reaction/hydrogenation sequence that allows diastereodivergent access to highly functionalized tetrahydropyrans, which can be used for the synthesis of designed analogues of this bioactive molecule.

Fluorogenic sydnone-based turn-on probes allow efficient labeling of proteins and cell imaging through a bioorthogonal strained promoted sydnone–alkyne cycloaddition reaction.