7654-03-7

Alzheimer's disease (AD) presents a complex pathology entangling numerous pathological factors, including amyloid-β (Aβ), metal ions, and reactive oxygen species (ROS). Increasing evidence reveals pathological connections among these distinct components in AD. For instance, the association between the amyloid cascade and metal ion hypotheses has introduced a novel pathogenic target: metal-bound Aβ. Investigation of such interconnections requires substantial research and can be expedited by chemical reagents that are able to modify multiple pathogenic factors in AD. Drug repurposing is an efficient approach for rediscovering previously utilized molecules with desirable biological and pharmaceutical properties as chemical reagents. Herein, we report the evaluation of three pre-approved drug molecules, selected based on their chemical structure and properties, as chemical reagents that can be used for elucidating the complicated pathology of AD.

Herein, we report a diaminocyclopentadienone ruthenium tricarbonyl complex-catalyzed synthesis of mono- or dialkylated acyl hydrazide compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary alcohols as alkylating reagents. Deuterium labeling experiments confirm that the alcohols were the hydride source in this cascade process. Density functional theory (DFT) calculations unveil the origin and the threshold between the mono- and dialkylation.

Prochiral hydrazones undergo efficient and highly selective hydrogenation in the presence of a chiral diphosphine ruthenium catalyst, yielding enantioenriched hydrazine products (up to 99% ee). The mild reaction conditions and broad functional group tolerance of this method allow access to versatile chiral hydrazine building blocks containing aryl bromide, heteroaryl, alkyl, cycloalkyl, and ester substituents. This method was also demonstrated on >150 g scale, providing a valuable hydrazine intermediate en route to an active pharmaceutical ingredient.

A borrowing-hydrogen reaction between amines and alcohols is an atom-economic way to prepare alkylamines, ideally with water as the sole byproduct. Herein, nickel catalysts are used for direct N-alkylation of hydrazides and arylamines using racemic alcohols. Moreover, a nickel catalyst of (S)-binapine was used for an asymmetric N-alkylation of benzohydrazide with racemic benzylic alcohols.

The invention discloses a method for preparing secondary amine or N'-alkyl hydrazide through nickel catalysis N-alkylation reaction. Amine or hydrazide is used as raw materials; alcohol is used as an alkylation agent; N-alkylation reaction is performed under the nickel catalysis condition; the secondary amine or N'-alkyl hydrazide is prepared. Compared with the prior art, the method provided by the invention has the advantages that the N-alkylation reaction is performed; active catalysts can be generated in situ by nickel salt and phosphine ligands; the preparation of catalysts in advance is avoided; the operation is simple and convenient; the experiment steps and the experiment cost are reduced. Cheap nickel is used as the catalysts; the consumption of the catalysts is low; the use of expensive and high-toxicity precious metal is avoided; the experiment cost is further reduced; the hydrogen borrowing strategy is utilized; the N'-alkylation of the hydrazide is realized for the first time; byproducts only contain water. Compared with other preparation methods, the method has the advantage that the reaction environment-friendly performance is realized.

An efficient method for the direct reductive alkylation of hydrazine derivatives with α-picoline-borane has been developed to synthesize a variety of N-alkylhydrazine derivatives. This method provided N,N-dialkylhydrazine derivatives and N-monoalkylhydrazine derivatives upon fine-tuning of the substrates and the reagent equivalency in a one-pot manner. The method was applied to the synthesis of active pharmaceutical ingredients of therapeutic drugs such as isocarboxazid.

A new family of ferrocenylphosphane ligands has been prepared. Their flexible synthesis allows many structural modifications. The asymmetric induction of these ligands was examined in the hydrogenation of functionalized C=C, C=O, and C=N bonds. The enantioselectivity of the reaction was strongly dependent on the substituent R at the position α to the ferrocene moiety. In many cases, both enantiomeric β-hydroxyesters of the reduction product can be obtained by simply replacing a dimethylamino group in the ligand with a methyl group.

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1-Acyl-2-alkylhydrazines were easily prepared by the reduction of acylhydrazones with triethylsilane in the presence of trifluoroacetic acid.

A process for the asymmetric hydrogenation of N-acylhydrazones to optically active N-acylhydrazines in the presence of a chiral phospholane catalyst complex, a process for the reductive N--N bond cleavage of N-acylhydrazine to amines with samarium diiodide, and a multistep process for converting keto group-bearing compounds to the corresponding optically active amino group-bearing compounds are disclosed.