Amongst nitrogen heterocycles of different ring sizes and oxidation statuses, dihydropyridines (DHP) occupy a prominent role due to their synthetic versatility occurrence in medicinally relevant compounds. One the most straightforward approaches polysubstituted DHP derivatives is provided by nucleophilic dearomatization readily assembled pyridines. In this article, we collect summarize reactions pyridines reported literature between 2010 mid-2018, complementing updating previous reviews...

The first stereoselective synthesis of enantioenriched axially chiral indole-quinoline systems is presented. strategy takes advantage an organocatalytic enantioselective Povarov cycloaddition 3-alkenylindoles and N-arylimines, followed by oxidative central-to-axial chirality conversion process, allowing for access to previously unreported biaryls. methodology also implemented the design preparation challenging compounds exhibiting two stereogenic axes. DFT calculations shed light on...

Abstract The “on‐demand” capture and utilization of CO 2 is effectively realized with a readily accessible dual function organic composite. covalent controlled derivatization graphene oxide (GO) surface naturally occurring arginine led to “smart” material capable capturing (chemisorption) from high‐purity flue‐gas as well low‐concentration streams ( i. e . direct air capture) concomitant chemical activation toward the incorporation into cyclic carbonates. overall integrated conversion (ICCC)...

A direct electroreductive functionalization of tropones employing aldehydes as alkylating agents is reported. This C(sp2)-H process leverages the mediation electroactive nickel complexes, enabling a wide range both native and substituted (44 examples) to be alkylated selectively at α-position in high yields (up 90%). Combined electrochemical, spectroelectrochemical, computational analyses disclosed whole mechanistic pathway revealed key role played by reduced Ni complexes activating tropone...

The catalytic enantioselective dearomatization of pyridines with nucleophiles represents a direct and convenient access to highly valuable dihydropyridines. Available methods, mostly based on N-acylpyridinium salts, give addition the C-2/C-6 pyridine nucleus, rendering 1,2-/1,6-dihydropyridines. Herein, we present an alternative approach this type reaction, employing activated N-benzylpyridinium salts in combination bifunctional organic catalyst. Optically active 1,4-dihydropyridines...

The development of the first chemo-, regio-, and stereoselective hetero-[6+4] -[6+2] cycloadditions heteroaromatic compounds via amino aza- diazafulvenes is presented. Pyrroles, imidazoles, pyrazoles substituted with a formyl group react an aminocatalyst to generate electron-rich hetero-6π-component that reacts in manner electron-deficient dienes olefins. For cycloaddition pyrrole system dienes, wide variation both reaction partners possible, providing attractive pyrrolo-azepine products...

Abstract The tandem catalytic functionalization/carboxylation of double as well triple carbon‐carbon bonds with CO 2 represent an emerging research area in synthetic organic methodology. In particular, the combination mild reaction conditions, stoichiometric acceptor/donorless conditions (visible light photoredox catalysis) and chiral catalysts contributed to a rapid development this intriguing capable creating chemical diversity/ complexity from readily available unsaturated hydrocarbons...

Nonbiaryl atropisomers are molecules defined by a stereogenic axis featuring at least one nonarene moiety. Among these, scaffolds bearing conformationally stable C(sp2)-C(sp3) have been observed in natural compounds; however, their enantioselective synthesis remains almost completely unexplored. Herein we disclose new class of chiral obtained with high levels stereoselectivity (up to 99% ee) means an organocatalytic asymmetric methodology. Multiple molecular motifs could be embedded this...

Abstract The utilization of CO 2 as an efficient and environmentally friendly chemical analogue is becoming a solid reality in the scenario. ‐based carbonylations have started paralleling more consolidated carboxylation procedures, opening new horizons perspectives carbon dioxide organic C1‐containing building block. advent site‐selective metal‐catalyzed protocols for fixation into scaffolds, under controlled reductive conditions, contributed substantially to development robust, efficient,...

An electrochemical allylation/alkylation of cyclic/acyclic ethers is presented via a C(sp 3 )–H activation, proceeding under cathodic reduction. The reaction shows broad functional group tolerance and high yields.

Catalytic addition of chiral enamines to azinium salts is a powerful tool for the synthesis enantioenriched heterocycles. An unprecedented asymmetric dearomative aldehydes activated N-alkylpyridinium presented. The process exhibits complete C-4 regioselectivity along with high levels diastereo- and enantiocontrol, achieving high-yielding broad range optically active 1,4-dihydropyridines. Moreover, presented methodology enables functionalized octahydropyrrolo[2,3-c]pyridines, core structure...

A perspective on the literature dealing with organocatalytic asymmetric preparation of axially chiral N-heterocycles is provided. particular focus devoted to rationalize synthetic strategies employed in each case. Moreover, specific classes organocatalysts are shown stand out as privileged motives for stereoselective such synthetically challenging molecular architectures. Finally, an overview main trends field given. 1 Introduction 2 Five-Membered Rings 2.1 Arylation 2.2 Dynamic Kinetic...

A nickel-catalyzed reductive cross-electrophile coupling between the redox-active N-trifluoroethoxyphthalimide and iodoarenes is documented. The protocol reproduces a formal arylation of trifluoroacetaldehyde under mild conditions in high yields (up to 88 %) with large functional group tolerance (30 examples). combined computational experimental investigation revealed pivotal solvent assisted 1,2-Hydrogen Atom Transfer (HAT) process generate nucleophilic α-hydroxy-α-trifluoromethyl...

Electrosynthesis is effectively employed in a general regio- and stereoselective alkylation of Morita–Baylis–Hillman compounds. The exposition N-acyloxyphthalimides (redox-active esters) to galvanostatic electroreductive conditions, following the sacrificial-anode strategy, proved an efficient practical method access densely functionalized cinnamate oxindole derivatives. High yields (up 80%) wide functional group tolerance characterized methodology. A tentative mechanistic sketch proposed...

Abstract The first peri‐ and stereoselective [10+4] cycloaddition between catalytically generated amino isobenzofulvenes electron‐deficient dienes is described. highly catalytic exhibits a broad scope with high yields, reflecting robust higher‐order cycloaddition. Experimental computational investigations support kinetic distribution of intermediate rotamers dictating the enantioselectivity, which relies heavily on additive effects.

We present an environmentally benign methodology for the covalent functionalization (arylation) of reduced graphene oxide (rGO) nanosheets with arylazo sulfones. A variety tagged aryl units were conveniently accommodated at rGO surface via visible-light irradiation suspensions carbon nanostructured materials in aqueous media. Mild reaction conditions, absence photosensitizers, functional group tolerance and high atomic fractions (XPS analysis) represent some salient features characterizing...

Abstract The first site‐selective electrochemical alkylation of tropones is realized by reacting 2‐acetoxytropones and redox‐active‐esters (RAEs). electroreductive protocol enables the preparation mono‐ disubstituted in high yields (up to 71%) under very mild conditions. Dedicated voltammetric measurements served for identification as a class valuable trapping agents nucleophilic radical species shed light on whole mechanistic profile. Wide tolerance towards functional groups (27 examples)...

Fluorinated JohnPhos-type ligands are proposed as accelerating tools in homogeneous gold(I) catalysis, with PedroPhosAuCl (Cat1) the most efficient one. The well corresponding gold complexes were synthesized high yields and fully characterized also via single-crystal X-ray diffraction. A secondary interaction between distal phenyl ring of phosphane ligand metal center is identified key for fine-tuning overall catalytic performance complexes. In particular, kinetic computational analysis...

The first enantioselective [12 + 2] cycloaddition has been developed for the construction of a chiral cycl[3.2.2]azine core, tricyclic moiety with central ring-junction nitrogen atom, by an operationally simple one-step organocatalytic process. reaction concept builds upon aminocatalytically generated 12π-components derived from 5H-benzo[a]pyrrolizine-3-carbaldehydes reacting different electron-deficient 2π-components and affording complex scaffold benzo[a]cycl[3.2.2]azine...

A carboxylative Ni-catalyzed tandem C-C σ-bond activation of cyclobutanones followed by CO2-electrophilic trapping is documented as a direct route to synthetically valuable 3-indanone-1-acetic acids. The protocol shows an adequate functional group tolerance and useful chemical outcomes (yield up 76%) when AlCl3 adopted additive. Manipulations the targeted cyclic scaffolds mechanistic proposal based on experimental evidence complete investigation.

Abstract The electrochemical carboxylation of Morita–Baylis–Hillman (MBH) acetates with CO2 is presented. process proceeds in the absence transition-metal catalysts and relies on cathodic reduction MBH to generate nucleophilic anions that are able trap low-pressure CO2. Valuable succinate derivatives obtained (20 examples) high yields (up 90%) excellent functional group tolerance. A remarkable substrate-controlled (electronic nature) regioselectivity transformation documented along a...

A carbonylation–carboxylation synthetic sequence, via double CO2 fixation, is described. The productive merger of a Ni-catalyzed cross-electrophile coupling manifold, with the use AlCl3, triggered cascade reaction formation three consecutive C–C bonds in single operation. This strategy traces an unprecedented route to ketones under Lewis acid assisted carbon dioxide valorization. Computational insights revealed unique function and labeling (13CO2) experiments validate genuine incorporation...

Abstract A new nickel catalyzed cross‐electrophile coupling for accessing γ‐lactams (isoindolinones) as well γ‐lactones (isobenzofuranones) via carbonylation with CO 2 is documented. The protocol exploits the synergistic role of redox‐active Ni(II) complexes and AlCl 3 a activator/oxygen scavenger, leading to formation wide range cyclic amides esters (28 examples) in good high yields (up 87 %). dedicated computational investigation revealed multiple roles played by . In particular,...

Abstract Despite the broad interest in ferrocene containing compounds, ferrocenyl substrates have been employed catalytic asymmetric settings only sporadically. Herein, Povarov reactions with ferrocenecarbaldehyde‐derived N ‐aryl imines are presented. This study demonstrates that stereoelectronic properties of do not preclude their engagement enantioselective phosphoric acid catalysis: cycloadducts derived from benzyl ‐vinylcarbamate were obtained good yields and nearly enantiopure form...

Abstract A highly stereoselective 1,3‐dipolar [6+4] cycloaddition towards bridged azabicyclo[4.3.1]decane scaffolds has been developed, reacting aldehydes, 2‐aminomalonates and tropone under mild conditions in the presence of a chiral phosphoric acid catalyst. The scope is demonstrated for series aldehydes 2‐aminomalonates, reaction proceeds high yields, >95:5 d.r. up to 99 % ee . transformations, as well mechanistic proposal, are presented.