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Over half of new therapeutic approaches fail in clinical trials due to a lack of target validation. As such, the development of new methods to improve and accelerate the identification of cellular targets, broadly known as target ID, remains a fundamental goal in drug discovery. While advances in sequencing and mass spectrometry technologies have revolutionized drug target ID in recent decades, the corresponding chemical-based approaches have not changed in over 50 y. Consigned to outdated stoichiometric activation modes, modern target ID campaigns are regularly confounded by poor signal-to-noise resulting from limited receptor occupancy and low crosslinking yields, especially when targeting low abundance membrane proteins or multiple protein target engagement. Here, we describe a broadly general platform for photocatalytic small molecule target ID, which is founded upon the catalytic amplification of target-tag crosslinking through the continuous generation of high-energy carbene intermediates via visible light-mediated Dexter energy transfer. By decoupling the reactive warhead tag from the small molecule ligand, catalytic signal amplification results in unprecedented levels of target enrichment, enabling the quantitative target and off target ID of several drugs including (+)-JQ1, paclitaxel (Taxol), dasatinib (Sprycel), as well as two G-protein-coupled receptors--ADORA2A and GPR40. [ABSTRACT FROM AUTHOR]

The interactions of biomolecules underpin all cellular processes, and the understanding of their dynamic interplay can lead to significant advances in the treatment of disease through the identification of novel therapeutic strategies. Protein–protein interactions (PPIs) in particular play a vital role within this arena, providing the basis for the majority of cellular signalling pathways. Despite their great importance, the elucidation of weak or transient PPIs that cannot be identified by immunoprecipitation remains a significant challenge, particularly in a disease relevant cellular environment. Recent approaches towards this goal have utilized the in situ generation of high energy intermediates that cross-link with neighboring proteins, providing a snapshot of the biomolecular makeup of the local area or microenvironment, termed the interactome. In this tutorial review, we discuss these reactive intermediates, how they are generated, and the impact they have had on the discovery of new biology. Broadly, we believe this strategy has the potential to significantly accelerate our understanding of PPIs and how they affect cellular physiology. [ABSTRACT FROM AUTHOR]

Palladium(II)-catalyzed C−H carbonylation reactions of methylene C−H bonds in secondary aliphatic amines lead to the formation of trans-disubstituted β-lactams in excellent yields and selectivities. The generality of the C−H carbonylation process is aided by the action of xantphos-based ligands and is important in securing good yields for the β-lactam products. [ABSTRACT FROM AUTHOR]

Palladium(II)-catalyzed C−H carbonylation reactions of methylene C−H bonds in secondary aliphatic amines lead to the formation of trans-disubstituted β-lactams in excellent yields and selectivities. The generality of the C−H carbonylation process is aided by the action of xantphos-based ligands and is important in securing good yields for the β-lactam products. [ABSTRACT FROM AUTHOR]

The chemistry of low‐valent intermediates continues to inspire new modes of reactivity across synthetic chemistry. But while the generation and reactivity of both carbenes and nitrenes are well‐established, difficulties in accessing oxene, their oxygen‐based congener, has severely hampered its application in synthesis. Here, we report a conceptually novel approach towards oxenoid reactivity through the violet‐light photolysis of tetrabutylammonium periodate. Computational studies reveal an unexpected geometric change upon periodate photoexcitation that facilitates intersystem crossing and near‐barrierless dissociation of triplet periodate into oxene. Under these operationally simple conditions, we have demonstrated the epoxidation of a wide range of substituted olefins, revealing unprecedented functional group compatibility. By overcoming the historic challenges associated with employing oxene as an intermediate in organic chemistry, we believe that this platform will inspire the development of new reactive oxygen‐based methodologies across industry and academia. [ABSTRACT FROM AUTHOR]

The preparation of C-iodo-N-Ts-aziridines with excellent cis-diastereoselectivity has been achieved in high yields by the addition of diiodomethyllithium to N-tosylimines and N-tosylimine-HSO2Tol adducts. This addition-cyclization protocol successfully provided a wide range of cis-iodoaziridines, including the first examples of alkyl-substituted iodoaziridines, with the reaction tolerating both aryl imines and alkyl imines. An ortho-chlorophenyl imine afforded a β-amino gem-diiodide under the optimized reaction conditions due to a postulated coordinated intermediate preventing cyclization. An effective protocol to assess the stability of the sensitive iodoaziridine functional group to chromatography was also developed. As a result of the judicious choice of stationary phase, the iodoaziridines could be purified by column chromatography; the use of deactivated basic alumina (activity IV) afforded high yield and purity. Rearrangements of electron-rich aryl-iodoaziridines have been promoted, selectively affording either novel α-iodo-N-Ts-imines or α-iodo-aldehydes in high yield. [ABSTRACT FROM AUTHOR]

The excellent cis-diastereoselective title synthesis provides a wide range of cis-iodoaziridines including the first examples of alkyl-substituted iodoaziridines (≥95 % ds.). [ABSTRACT FROM AUTHOR]