Late-stage guanine C8-H alkylation of nucleosides, nucleotides, and oligonucleotides via photo-mediated Minisci reaction.

Chemically modified nucleosi(ti)des and functional oligonucleotides (ONs, including therapeutic oligonucleotides, aptamer, nuclease, etc.) have been identified playing an essential role in the areas of medicinal chemistry, chemical biology, biotechnology, and nanotechnology. Introduction of functional groups into the nucleobases of ONs mostly relies on the laborious de novo chemical synthesis. Due to the importance of nucleosides modification and aforementioned limitations of functionalizing ONs, herein, we describe a highly efficient site-selective alkylation at the C8-position of guanines in guanosine (together with its analogues), GMP, GDP, and GTP, as well as late-stage functionalization of dinucleotides and single-strand ONs (including ssDNA and RNA) through photo-mediated Minisci reaction. Addition of catechol to assist the formation of alkyl radicals via in situ generated boronic acid catechol ester derivatives (BACED) markedly enhances the yields especially for the reaction of less stable primary alkyl radicals, and is the key to success for the post-synthetic alkylation of ONs. This method features excellent chemoselectivity, no necessity for pre-protection, wide range of substrate scope, various free radical precursors, and little strand lesion. Downstream applications in disease treatment and diagnosis, or as biochemical probes to study biological processes after linking with suitable fluorescent compounds are expected.

Global Research Trends in Adipose Stem Cell Tissue Engineering: A Scientometric Research.

Adipose Stem Cell Tissue Engineering (ASCTE) has emerged as a promising field of research in recent years. To gain comprehensive insights into this field, we conducted a comprehensive bibliometric analysis using Web of Science Core Collection and various bibliometric tools, including CiteSpace, VOS viewer, and R-Bibliometrix. Our analysis focuses on the historical development and evolution of active topics in ASCTE from a time-dynamics perspective, covering 4522 publications, 3924 academic institutions, and 873 journals, with significant growth observed over the past two decades. In terms of the global research landscape, the United States and China dominate the field. Shanghai Jiao Tong University, the University of Pittsburgh, and Ming Ho University are the top three institutions contributing to research in this area. Biomaterials is identified as the central journal in terms of cocitation analysis. Our analysis also reveals new areas of development, such as 3D printing, platelet lysate, and clinical practice, as well as current trends in hydrogels, nanomaterials, and extracellular vesicles. These findings point to exciting prospects for future ASCTE research. Unlike previous subjective reviews, our bibliometric analysis provides an objective assessment of the current state and emerging trends in ASCTE research, allowing researchers to identify popular research areas and explore new directions in this dynamic field.

Palladium-Catalyzed C-H Olefination for Nucleic Acid Production.

The palladium-catalyzed direct C-H olefination of unprotected uridine, 2'-deoxyuridine, uridine monophosphate, and uridine analogues are described here. This protocol provides an efficient, atom-economical, and environmentally friendly method for the introduction of an alkenyl group at the C5 position of the uracil without pre-functionalization. A series of C5-alkenylated uridine analogues, including some biologically significant compounds and potential pharmaceutical candidates, were synthesized with exposed hydroxyl groups on the ribose. © 2023 Wiley Periodicals LLC. Basic Protocol 1: The reaction of uridine, 2'-deoxyuridine, and sofosbuvir for the C-H olefination with methyl acrylate Basic Protocol 2: The reaction of uridine and 2'-deoxyuridine for the C-H olefination with styrene.

Azole-Directed Cobalt-Catalyzed Asymmetric Hydrogenation of Alkenes.

The azole-directed cobalt-catalyzed asymmetric hydrogenation of alkenes has been developed with high efficiency. With this approach, chiral pyrazole compounds were obtained in quantitative yields and excellent enantioselectivities (up to 99 % ee) under mild conditions, and the hydrogenation was conducted on a gram scale with up to 2000 TON. Several useful applications were demonstrated including the convenient introduction of ß-chirality to a drug intermediate containing an azole ring.