Jie Liu

Aryl amines are privileged structural motifs ubiquitous in pharmaceuticals, agrochemicals, and natural products. Herein, we report an electrocatalytic reductive coupling of nitroarenes with alkyl halides that enables the direct and step‐economic synthesis of N ‐alkylarylamines. This protocol features mild electrochemical conditions, broad functional group tolerance, and an exceptionally wide substrate scope, accommodating both benzylic and aliphatic halides. The synthetic utility of this method is further underscored by gram‐scale synthesis and a series of downstream derivatizations, highlighting its practicality and sustainability.

Géométrie des variétés de Fano : sous-faisceaux du fibré tangent et diviseur fondamental: Cette thèse est consacrée à l'étude de la géométrie des variétés de Fano complexes en utilisant les propriétés des sous-faisceaux du fibré tangent et la géométrie du diviseur fondamental. Les résultats principaux compris dans ce texte sont : (i) Une généralisation de la conjecture de Hartshorne: une variété lisse projective est isomorphe à un espace projectif si et seulement si son fibré tangent contient un sous-faisceau ample.(ii) Stabilité du fibré tangent des variétés de Fano lisses de nombre de Picard un : à l'aide de théorèmes d'annulation sur les espaces hermitiens symétriques irréductibles de type compact M, nous montrons que pour presque toute intersection complète générale dans M, le fibré tangent est stable. La même méthode nous permet de donner une réponse sur la stabilité de la restriction du fibré tangent de l'intersection complète à une hypersurface générale.(iii) Non-annulation effective pour des variétés de Fano et ses applications : nous étudions la positivité de la seconde classe de Chern des variétés de Fano lisses de nombre de Picard un. Ceci nous permet de montrer un théorème de non-annulation pour les variétés de Fano lisses de dimension n et d'indice n-3. Comme application, nous étudions la géométrie anticanonique des variétés de Fano et nous calculons les constantes de Seshadri des diviseurs anticanoniques des variétés de Fano d'indice grand.(iv) Diviseurs fondamentaux des variétés de Moishezon lisses de dimension trois et de nombre de Picard un : nous montrons l'existence d'un diviseur lisse dans le système fondamental dans certain cas particulier.

Selective reduction of amides is of great importance for generating versatile building blocks in both academia and industry. However, in contrast to ketones and carboxylic esters, amides are generally considered highly unreactive members of the carbonyl family owing to their low electrophilicity and thermodynamic stability. Herein, we describe an efficient electroreduction of amides to amines using protons as the hydrogen source. A combination of readily available zirconium catalyst (Cp₂ZrCl₂) with a stoichiometric halosilane enables the selective deoxygenative electroreduction process. Preliminary mechanistic investigations support the involvement of an unconventional α-aminocarbene species as the key intermediate, which is generated from the electroreductive C═O bond scission of an amide. Without the necessity of flammable H₂ gas or sensitive hydrides, this electrochemical protocol is showcased by highly selective and straightforward synthesis of various functionalized and structurally diverse amines under mild conditions. Furthermore, the application of this protocol is demonstrated through valuable and practical access to N-α-deuterated amines using cost-effective and abundant deuterium sources.

Catalytic reduction of carboxylic acids to valuable chemicals is highly desirable yet challenging for both biomass conversion and organic synthesis. Here we describe an efficient and sustainable electrocatalytic hydrogenation of carboxylic acids with amines utilizing protons as the hydrogen source. The application of an earth-abundant cobalt complex enables electrochemical generation of a cobalt-hydride intermediate, which serves as the key catalytically active species for this reductive process. Obviating the need for flammable H₂ gas or sensitive hydrides, this general hydrogenative coupling of carboxylic acids with amines and nitroarenes allows producing a wide range of structurally diverse complex alkylamines under mild electrocatalytic conditions. Furthermore, the practicality and versatility of this protocol are demonstrated through its application in valuable isotope labeling using readily available deuterium sources.

We describe a straightforward and efficient electrochemical nucleophilic aromatic substitution of diaryl ethers, including lignin 4-O-5 models and polyphenylene oxide (PPO).

Catalytic hydrogenation is one of the most important transformations in both academia and industry. Compared with direct hydrogenation with molecular hydrogen or transfer hydrogenations with hydrides, electrohydrogenation provides an alternative and practical pathway using proton as the hydrogen source. In this review, we have summarized the recent advances in electrohydrogenations of polar and non‐polar unsaturated compounds catalyzed by earth‐aubundant metal complexes. In addition, we also present a detailed discussion of the scope and limitations, plausible mechanisms and the opportunities for further development.

We describe a straightforward and efficient electrochemical approach for the cathodic benzylic C–H hydroxyalkylation and arylation of N -(alkyloxy)phthalimides mediated by the 1,2-HAT of alkoxy radicals.

Carboxylic acids are widely available and generally inexpensive from abundant biomass feedstocks, and they are suitable and generic coupling partners in synthetic chemistry. Reported herein is an electroreductive coupling of stable and versatile carboxylic acids with (hetero)arenes using protons as the hydrogen source. The application of an earth-abundant titanium catalyst has significantly improved the deoxygenative reduction process. Preliminary mechanistic studies provide insights into the deoxygenative reduction of in-situ generated ketone pathway, and the intermediacy generation of ketyl radical and alkylidene titanocene. Without the necessity of pressurized hydrogen or stoichiometric hydride as reductants, this protocol enables highly selective and straightforward synthesis of various functionalized and structurally diverse alkylbenzenes under mild conditions. The utility of this reaction is further demonstrated through practical and valuable isotope incorporation from readily available deuterium source.

A Pd-catalyzed highly regio- and stereoselective hydrocyanation was developed, providing a novel approach to the stereodivergent synthesis of β-cyano-substituted acrylates in good yields with a wide substrate scope. The judicious selection of ligands was crucial for elegant control over the stereodivergence. Furthermore, the success of the E-hydrocyanation hinges on the right matching of Pd and L1, which not only ensured the catalytic activity but also prevented the formation of α-cyanation products.

N‐Heterocyclic amines have been known as an important class of nitrogen‐containing molecules with a wide range of applications. Described here is a mild and efficient electrochemical desulfurizative amination of readily accessible heteroaromatic thiols without necessity of metal catalyst. The key to success for this reaction is the in‐situ generation of a hypervalent iodine reagent as an organocatalyst from iodoarene by anodic oxidation. This mild desulfurizative amination presents ample substrate scope and good functional group tolerance without the use of extra stoichiometric chemical oxidants. As only electrons serve as the oxidation reagents, this method offers a straightforward and sustainable manner towards versatile N‐heterocyclic amines, including late‐stage functionalization of pharmaceutically relevant molecules.