Xuan Wang

Bio: Xuan Wang is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Total synthesis & Aldol condensation. The author has an hindex of 6, co-authored 13 publications receiving 125 citations.

Diversified strategy for the synthesis of DNA-encoded oxindole libraries.

Abstract: DNA-encoded library technology (DELT) employs DNA as a barcode to track the sequence of chemical reactions and enables the design and synthesis of libraries with billions of small molecules through combinatorial expansion. This powerful technology platform has been successfully demonstrated for hit identification and target validation for many types of diseases. As a highly integrated technology platform, DEL is capable of accelerating the translation of synthetic chemistry by using on-DNA compatible reactions or off-DNA scaffold synthesis. Herein, we report the development of a series of novel on-DNA transformations based on oxindole scaffolds for the design and synthesis of diversity-oriented DNA-encoded libraries for screening. Specifically, we have developed 1,3-dipolar cyclizations, cyclopropanations, ring-opening of reactions of aziridines and Claisen-Schmidt condensations to construct diverse oxindole derivatives. The majority of these transformations enable a diversity-oriented synthesis of DNA-encoded oxindole libraries which have been used in the successful hit identification for three protein targets. We have demonstrated that a diversified strategy for DEL synthesis could accelerate the application of synthetic chemistry for drug discovery.

Open-Air Alkylation Reactions in Photoredox-Catalyzed DNA-Encoded Library Synthesis.

Abstract: DNA-encoded library (DEL) technology is a powerful tool commonly used by the pharmaceutical industry for the identification of compounds with affinity to biomolecular targets. Success in this endeavor lies in sampling diverse chemical libraries. However, current DELs tend to be deficient in C(sp3) carbon counts. We report unique solutions to the challenge of increasing both the chemical diversity of these libraries and their C(sp3) carbon counts by merging Ni/photoredox dual catalytic C(sp2)-C(sp3) cross-coupling as well as photoredox-catalyzed radical/polar crossover alkylation protocols with DELs. The successful integration of multiple classes of radical sources enables the rapid incorporation of a diverse set of alkyl fragments.

Divergent Strategy in Natural Product Total Synthesis.

Abstract: The divergent total syntheses of complex natural products from a common intermediate have attracted enormous attention in the chemical community in the past few years because it can improve the efficiency of chemical synthesis. A number of powerful and unified strategies have been developed by emulating the natural biosynthesis or through innovative transformations. This review focuses on the total synthesis of natural products by applying divergent strategies and the literature covering from 2013 to June 2017. On the basis of where the diversity comes from, the examples are grouped into three parts and discussed in detail. In each group, the examples that synthesize natural products belonging to the same subfamily are put together to contrast with one another.

A brief history of antibiotics and select advances in their synthesis.

Abstract: The advent of modern antibiotics contributed enormously to the dramatic extension of human lifespan since their discovery by virtue of their lethal and selective action against pathogenic microbes. And yet despite our powerful arsenal of weapons against these pathogens, the war against them has not been won. And it may never be. Drug resistance is still menacing the society with many lives being lost due to deadly infections caused by continuously evolving strains spread beyond our means to eradicate them or prevent their spreading. Herein, the emergence and evolution of antibiotics is briefly reviewed, and a select number of total syntheses of naturally occurring antibiotics from the authors' laboratories are highlighted. The article concludes with a strong endorsement of the current efforts to intensify our fight against these dangerous pathogens with the hope that, this time, these initiatives will be sufficiently focused and serious enough so as to achieve our set goals of, at least, being prepared and ahead of them as part of our drive to improve humanity's healthcare and wellbeing.

Application of (4+3) cycloaddition strategies in the synthesis of natural products

Abstract: (4+3) Cycloadditions have been widely applied in synthesis, and in this review article, we summarize some of the more recent applications, including formal (4+3) cycloadditions, in the synthesis of natural products. Many of these natural product target frameworks have cycloheptane subunits, for which the (4+3) cycloaddition is a convergent strategy for their assembly. Some natural product targets do not possess seven membered rings, and their syntheses have exploited the functional group endowed (4+3) cycloadducts resulting from these reactions, highlighting the utility of this methodology for the synthesis of a range of complex molecules.

DNA-Encoded Library Screening as Core Platform Technology in Drug Discovery: Its Synthetic Method Development and Applications in DEL Synthesis

Abstract: DNA-encoded library technology (DELT) was introduced to our medicinal chemistry society more than 20 years ago. The application of DELT in the development of clinical candidates has been actively reported in the literature recently. A few representative examples include RIP1K inhibitors for inflammatory diseases and sEH inhibitors for endothelial dysfunction or abnormal tissue repair, among many others. Here, the authors would like to recall the recent developments in on-DNA synthetic methodologies for DEL construction and to analyze recent examples in the literature of DELT-based drug development efforts pursued in both the academic and industrial sectors. With this perspective, we hope to provide a useful summary of recent DELT-based drug discovery research and to discuss the future scope of DELT in medicinal chemistry.