A highly efficient synthesis of sitagliptin, a potent and selective DPP-4 inhibitor for the treatment of type 2 diabetes mellitus (T2DM), has been developed. The key dehydrositagliptin intermediate 9 is prepared in three steps in one pot and directly isolated in 82% yield and >99.6 wt % purity. Highly enantioselective hydrogenation of dehydrositagliptin 9, with as low as 0.15 mol % of Rh(I)/(t)Bu JOSIPHOS, affords sitagliptin, which is finally isolated as its phosphate salt with nearly perfect optical and chemical purity. This environmentally friendly, 'green' synthesis significantly reduces the total waste generated per kilogram of sitagliptin produced in comparison with the first-generation route and completely eliminates aqueous waste streams. The efficiency of this cost-effective process, which has been implemented on manufacturing scale, results in up to 65% overall isolated yield.
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http://dx.doi.org/10.1021/ja902462q | DOI Listing |
Sci Rep
December 2024
College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
Accurate prediction of runoff is of great significance for rational planning and management of regional water resources. However, runoff presents non-stationary characteristics that make it impossible for a single model to fully capture its intrinsic characteristics. Enhancing its precision poses a significant challenge within the area of water resources management research.
View Article and Find Full Text PDFNat Commun
December 2024
National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan, P.R. China.
Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce because these non-strained aromatics exhibit inert reactivities, making them relatively inactive for performing a dearomatization/cleavage sequence. Here, we disclose a cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles to access the pyrazolopyridopyridazin-6-one skeleton through a single-operation protocol. By converting a five-membered aza-arene into a five-unit spine of a 6/6 fused-bicyclic, this work unlocks a ring-opening reactivity of the pyrazole core that involves a formal C = N bond cleavage while retaining the highly reactive N-N bond in the resulting product.
View Article and Find Full Text PDFNat Commun
December 2024
AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Sukarrieta, Spain.
Marine brown algae produce the highly recalcitrant polysaccharide fucoidan, contributing to long-term oceanic carbon storage and climate regulation. Fucoidan is degraded by specialized heterotrophic bacteria, which promote ecosystem function and global carbon turnover using largely uncharacterized mechanisms. Here, we isolate and study two Planctomycetota strains from the microbiome associated with the alga Fucus spiralis, which grow efficiently on chemically diverse fucoidans.
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December 2024
Xiamen Key Laboratory of Optoelectronic Materials and Advanced Manufacturing, Institute of Luminescent Materials and Information Displays, College of Materials Science and Engineering, Huaqiao University, Xiamen, Fujian, China.
Highly efficient perovskite solar cells (PSCs) in the n-i-p structure have demonstrated limited operational lifetimes, primarily due to the layer-to-layer ion diffusion in the perovskite/doped hole-transport layer (HTL) heterojunction, leading to conductivity drop in HTL and component loss in perovskite. Herein, we introduce an ultrathin (~7 nm) p-type polymeric interlayer (D18) with excellent ion-blocking ability between perovskite and HTL to address these issues. The ultrathin D18 interlayer effectively inhibits the layer-to-layer diffusion of lithium, methylammonium, formamidium, and iodide ions.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China.
DNA helicases play a pivotal role in maintaining genome integrity by unwinding the DNA double helix and are often considered promising targets for drug development. However, assessing specific DNA helicase activity in living cells remains challenging. Herein, the first anchor-embedded duplex (ATED) probe, 17GC, is constructed to uniquely monitor the unwinding activity of Werner syndrome helicase (WRN), a clinical anticancer target.
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