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Information × Registration Number 0224U001257, 0120U104008 , R & D reports Title Development of continuous-flow approach of safe and scalable utilization of non-stabilized diazoalkanes as reagents for organic synthesis popup.stage_title Head Volochnyuk Dmytro M., Доктор хімічних наук Registration Date 19-01-2024 Organization Institute of Organic Chemistry NAS of Ukraine popup.description2 Using the UOSlab®FlowReactor D1000 flow reactor, we successfully optimized conditions for the safe generation of diazomethane with a productivity of up to 0.45 mol/hour from nitrosomethylurea with aqueous KOH solution. Using the UOSlab® FlowReactor UF365/450 flow photochemical reactor, a 'pseudo-telescopic' Arndt-Eistert homologation protocol for carbonic acids was developed. Within the study of the synthetic potential of diazoketones as stable-storage reagents, the limits of their application as surrogates for halogen ketones in heterocyclic chemistry was explored. It was shown that in a 'one-pot' protocol, corresponding AADDKs are convenient reagents for synthesizing various thiazoles in reactions with thioureas and thioamides, while preserving the configuration of the chiral center from the original amino acid. Diazoketones, derived from chiral α- and β-amino acids, were studied in a series of transition metals catalyzed transformations. Conditions were found for preparative Rh-catalyzed intramolecular transformation of diazoketones into corresponding azetidones and pyrrolidones with preservation of chirality. In the case of diazoketones derived from α-amino acids, it was possible to avoid the use of Rh by replacing the metal-catalytic activation step of the reaction with photochemical LED irradiation at the 450 nm wavelength. Combining the flow generation with diazomethane’s ability to react in 1,3- cycloadditions with electron-deficient alkenes made it possible to synthesize pyrazolines in quantities exceeding hundreds of grams and define the limits of application of this reaction. It was found that the reaction scope is limited by steric hindrances around the double C=C bond. The dependance of the stability and reactivity of the obtained 4,5-dihydro-3H-pyrazoles (Δ1-pyrazolines) on their structural features was also studied. Product Description popup.authors Volochniuk Dmytro M. Gaiday Oleksandr V. Nosyk Pavlo S. Pashenko Olexander Ye Pendyuh Vyachislav V. Rozhenko Oleksandr Sergiy V. Ryabukhin Slobodyanyuk Yevgen Yu. Shuvakin Serhii I Yakovleva Hanna popup.nrat_date 2024-01-19 Close