Coupling Cyclization Reaction Research Articles

Synthesis of (−)-Epi-Indolactam V by an Intramolecular Buchwald–Hartwig C–N Coupling Cyclization Reaction

The synthetic efforts toward the concise synthesis of (-)-indolactam V from simple and commercially available starting materials using palladium- and copper-catalyzed intramolecular N-arylation strategy for the elaboration of the requisite nine-membered lactam ring as the key step are described. The incorporation of a turn-inducing structural element along the linear precursor was fundamental to achieve the heterocyclization step as well as obtain the correct regio- and chemoselectivity. The stereoselective nature in the C-N coupling cyclization reaction is interpreted in terms of minimization of allylic strain at the transition state for the palladium-amido complex formation. Meanwhile, the synthesis of the (-)-epi-indolactam V and its enantiomer have been accomplished.

ChemInform Abstract: Efficient Synthesis of N‐(Buta‐2,3‐dienyl) Amides from Terminal N‐Propargyl Amides and Their Synthetic Potential Towards Oxazoline Derivatives.

AbstractA series of N‐allenyl amides (III) prepared from N‐propargyl amides (I) are efficiently transformed into the target oxazole derivatives by palladium‐catalyzed coupling—cyclization reaction with organic iodides (IV).

Synthesis of green and blue fluorescent ladder-type conjugated imidazolium compounds

The synthetic route to ladder-type conjugated imidazolium compounds consisting of Suzuki coupling, chlorination, and intramolecular cyclization reactions was developed. The optical properties of materials and theoretical calculations were investigated to demonstrate that methylene- and ethylene-bridged imidazolium compounds show green and blue fluorescence, respectively. The coordination ability of the counter anion had an influence on the solubility and fluorescence quantum yield of the compounds.

Cyclization–carbonylation–cyclization coupling reaction of α,β-alkynic hydrazones with palladium(ii)-bisoxazoline catalyst

A cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of α,β-alkynic hydrazones, catalyzed by (box)Pd(II) complexes, afforded symmetrical ketones bearing two pyrazole groups in good to excellent yields. This method is applicable to a broad range of substrates.

ChemInform Abstract: Cyclization—Carbonylation—Cyclization Coupling Reactions of N‐Propargylanilines and o‐Alkynylphenols with Palladium(II)—Bisoxazoline Catalysts.

AbstractA CCC‐coupling of N‐propargylanilines (I) or o‐alkynylphenols (VIII) in the presence of Pd(II)‐complexes with racemic bisoxazoline ligands is investigated.

ChemInform Abstract: Cyclization—Carbonylation—Cyclization Coupling Reaction of γ‐Propynyl‐1,3‐diketones with Palladium(II)‐Bisoxazoline Catalyst.

Cyclization–carbonylation–cyclization coupling reaction (CCC-coupling reaction) of γ-propynyl-1,3-diketones catalyzed by (box)PdII complexes afforded symmetrical ketones bearing two oxabicyclic groups in moderate to excellent yields.

Cyclization-Carbonylation-Cyclization Coupling Reactions of N-Propargylanilines and o-Alkynylphenols with Palladium(II)-Bisoxazoline Catalysts

Cyclization–carbonylation–cyclization coupling reactions (CCC-coupling reactions) of <i>N</i>-propargylanilines and <i>o</i>-alkynylphenols catalyzed by (box)Pd(II) complexes afforded symmetrical bis(quinolin-3-yl) and bis(benzofuran-3-yl) ketones, respectively, in moderate to excellent yields.

Sequential Sonogashira Coupling-Cyclization Reaction with CuO-Fe3O4

Key words magnetite - copper - palladium - Sonogashira coupling - cyclization

Cyclization–carbonylation–cyclization coupling reaction of γ-propynyl-1,3-diketones with palladium(ii)-bisoxazoline catalyst

Cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of γ-propynyl-1,3-diketones catalyzed by (box)Pd(II) complexes afforded symmetrical ketones bearing two oxabicyclic groups in moderate to excellent yields.

ChemInform Abstract: Palladium‐Catalyzed Tandem Reaction to Construct Benzo[c]phenanthridine: Application to the Total Synthesis of Benzo[c]phenanthridine Alkaloids.

AbstractA Pd‐catalyzed tandem ring opening—cross coupling—cyclization reaction of o‐iodobenzoates (I) with azabicycle (II) is the key step in the synthesis of benzophenanthridine alkaloids like avicine (IVa), chelerythrine (IVb) or nitidine (IVc).

ChemInform Abstract: Cyclization—Carbonylation—Cyclization Coupling Reactions of Propargyl Acetates and Amides with Palladium(II)—Bisoxazoline Catalysts.

AbstractThe reaction gives symmetric ketones containing two heterocyclic groups.

ChemInform Abstract: Pd/Cu‐Catalyzed Cascade Sonogashira Coupling/Cyclization Reactions to Highly Substituted 3‐Formyl Furans.

AbstractA diversity of α‐bromoenaminones (I) and (IV) smoothly undergoes Pd/Cu‐catalyzed cascade Sonogashira cross coupling—cyclization reaction with aromatic and aliphatic terminal alkynes (II) to give polysubstituted 3‐formylfuran derivatives (III) and (V), resp., in good yields.

Cyclization–Carbonylation–Cyclization Coupling Reactions of Propargyl Acetates and Amides with Palladium(II)–Bisoxazoline Catalysts

Die Titelreaktionssequenz mit Propargylacetaten 1 oder -amiden 2 in Gegenwart eines Palladium(II)-Bisoxazolin(box)-Katalysators lieferte symmetrische Ketone vom Typ 3 und 4 mit zwei heterocyclischen Einheiten in mäßigen bis ausgezeichneten Ausbeuten (siehe Schema; tfa=Trifluoracetat). Die Verbindungen 3 wurden in Ketone mit zwei 3(2H)-Furanonringen überführt. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Cyclization–Carbonylation–Cyclization Coupling Reactions of Propargyl Acetates and Amides with Palladium(II)–Bisoxazoline Catalysts

Cyclization–Carbonylation–Cyclization Coupling Reactions of Propargyl Acetates and Amides with Palladium(II)–Bisoxazoline Catalysts

ChemInform Abstract: Palladium‐Catalyzed Cyclization of N‐Alkynyl Aminomalonates.

AbstractA novel access towards pyrrolidines, e.g. (III), and piperidines (V) is presented, involving the Pd‐catalyzed tandem cyclization—coupling reaction of N‐alkynyl aminomalonates with aryl and alkenyl iodides.

Copper(I)-Catalyzed Intramolecular Caryl-O Bond-Forming Cyclization for the Synthesis of 1,4-Benzodioxines and Its Application in the Total Synthesis of Sweetening Isovanillins

Various substituted 1,4-benzodioxines were synthesized through an Ullmann-type intramolecular Caryl-O coupling cyclization reaction using a catalytic amount of BINOL-CuI complex. This methodology was successfully utilized as the key step in the total synthesis of isovanillyl sweetening agents 5-(2,3-dihydro-1,4-benzodioxin-2-yl)-2-methoxyphenol and 5-(2,3-dihydro-1,4-benz­oxathiin-2-yl)-2-methoxyphenol in 15.8% and 14.85% overall yields in five steps from isovanillin.

ChemInform Abstract: Facile Assembly of Fused Isoquinolines by Gold(I)‐Catalyzed Coupling—Cyclization Reactions Between o‐Alkynylbenzaldehydes and Aromatic Amines Containing Tethered Nucleophiles.

A gold(I)-catalyzed, operationally simple coupling-cyclization technique was developed for the synthesis of isoquinoline-fused polycyclic compounds. The reaction makes use of two coupling partners such as o-alkynylbenzaldehydes and aromatic amines having tethered nucleophiles. The reaction is easy to perform, broad in scope, and allows the generation of a number of biologically important heterocyclic motifs from readily accessible starting materials. A mechanism for the reaction is discussed.

Copper(I)-Catalyzed Synthesis of Benzoxazoles and Benzimidazoles

Reported is a synthesis of benz­oxazoles and benzimidazoles by a ligand-free copper-catalyzed C-N coupling-cyclization reaction of ortho-halophenols with ortho-haloanilines. Among the copper sources, CuI showed the highest catalytic activity. Polar solvents, for example MeCN, were shown to give higher yields of products than unpolar solvent, for example toluene. The N,N-dimethyl­glycine ligand was shown to afford a slightly higher yield under the same reaction conditions. A mechanism of sequential phenol and aniline addition to carbodiimide followed by intra­molecular C-N coupling was proposed without verification.

Facile Assembly of Fused Isoquinolines by Gold(I)‐Catalyzed Coupling–Cyclization Reactions between o‐Alkynylbenzaldehydes and Aromatic Amines Containing Tethered Nucleophiles

AbstractA gold(I)‐catalyzed, operationally simple coupling–cyclization technique was developed for the synthesis of isoquinoline‐fused polycyclic compounds. The reaction makes use of two coupling partners such as o‐alkynylbenzaldehydes and aromatic amines having tethered nucleophiles. The reaction is easy to perform, broad in scope, and allows the generation of a number of biologically important heterocyclic motifs from readily accessible starting materials. A mechanism for the reaction is discussed.

Palladium-catalyzed synthesis of 1,3,4-alkatrien-2-yldihydrofurans from 2,3-allenylacetylacetates and propargylic carbonates and their application to synthesize polysubstituted dihydrofurylcyclopentenones

An efficient route to 1,3,4-alkatrien-2-yldihydrofurans via a highly chemo- and regioselective palladium(0)-catalyzed coupling–cyclization reaction of 2-(2′,3′-allenyl)acetylacetates with propargylic carbonates was reported. The reaction proceeded smoothly under neutral conditions, affording the O-attacked five-membered products with a 1,3,4-trienyl substituent exclusively in good to excellent yields. The products can be efficiently applied to the synthesis of polysubstituted 2-(dihydrofuryl)cyclopentenone derivatives via a catalytic Pauson–Khand reaction under ambient conditions.