A conceptual strategy for a formal α-alkylation of α-methylene ketones was developed. Diverse 1° and 2° alkyl substituents were generated in the α-position of various ketones via synthesis of enaminone (step 1) and treatment with organomagnesium (step 2) with subsequent catalytic hydrogenation (step 3, 1° alkyl) or organocopper reagents (step 4, 2° alkyl). Tolerance toward ester, Boc-protected amine, and α-fluoro-substituted ketone moieties was demonstrated.
View Article and Find Full Text PDFA one-step synthesis of functionalized 3-azabicyclo[3.2.0]heptanes by [2+2]-photochemical intermolecular cycloaddition of N-benzylmaleimide to alkenes was elaborated.
View Article and Find Full Text PDFIntramolecular photochemical [2 + 2]-cyclization of acetophenone enamides gave 2-azabicyclo[3.2.0]heptanes, advanced building blocks for drug discovery.
View Article and Find Full Text PDFWe have developed a rapid two-step synthesis of substituted 3-azabicyclo[3.2.0]heptanes which are attractive building blocks for drug discovery.
View Article and Find Full Text PDFIn the context of drug discovery, novel spirocyclic pyrrolidines have been synthesized in two steps from common three- to seven-membered-ring (hetero)alicyclic ketones. The key transformation is a reaction between an electron-deficient exocyclic alkene and an in situ generated N-benzyl azomethine ylide. The developed method has been used to synthesize the central diamine core of the known antibacterial agents Sitafloxacin and Olamufloxacin.
View Article and Find Full Text PDFA series of novel sulfonamide substituted heteroleptic salan titanium(IV)-bis-chelates complexed to 2,6-pyridinedicarboxylic acid were synthesized, structurally characterized and evaluated for their anticancer activity against two human carcinoma cell lines. All cytotoxic complexes showed complete inhibition of cell growth at active concentration, two complexes based on pyrrolidine and azepane substituted sulfonamides displayed IC50 values below 1.7 μM and are more cytotoxic than cisplatin in both tested cell lines.
View Article and Find Full Text PDFA set of novel SO2-containing azabicyclo[3.n.1]alkanes has been synthesized by the double-Mannich annulation of of the corresponding monocyclic S-ketones.
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