Results 1 to 10 of about 5,277 (165)

3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles [PDF]

Beilstein Journal of Organic Chemistry
A high-yielding method for the synthesis of 3-arylbenzo[4,5]thieno[3,2-b]pyrroles has been developed via pyrrole ring annulation to the aromatic benzo[b]thiophene system, using 3-arylazirines as a N‒C=C synthon.
Julia I. Pavlenko, Pavel A. Sakharov, Anastasiya V. Agafonova, Derenik A. Isadzhanyan, Alexander F. Khlebnikov, Mikhail S. Novikov   +5 more
doaj   +2 more sources

Base-controlled annulation of tryptamine-derived isocyanides with nitrile imines for access to polycyclic spiroindoline derivatives

Green Synthesis and Catalysis, 2023
An annulation reaction of tryptamine-derived isocyanides with hydrazonyl chlorides in the presence of bases was developed. Controlled by different bases, [1+ ​2+3] annulation and [1+ ​2+3]/[2 ​+ ​3] annulation cascade were realized.
Xiaofeng Wang, Luorong Yuan, Xiaoping Xu, Shunjun Ji   +3 more
doaj   +1 more source

Copper(II)-Catalyzed (3+2) Cycloaddition of 2H-Azirines to Six-Membered Cyclic Enols as a Route to Pyrrolo[3,2-c]quinolone, Chromeno[3,4-b]pyrrole, and Naphtho[1,8-ef]indole Scaffolds

Molecules, 2022
A method for the [2+3] pyrroline annulation to the six-membered non-aromatic enols using 3-aryl-2H-azirines as annulation agents is developed in the current study.
Pavel A. Sakharov, Nikolai V. Rostovskii, Alexander F. Khlebnikov, Mikhail S. Novikov   +3 more
doaj   +1 more source

Selective Syntheses of Coumarin and Benzofuran Derivatives Using Phenols and α-Methoxy-β-ketoesters

SynOpen, 2023
Selective syntheses of coumarin and benzofuran derivatives were achieved via HClO4-mediated intermolecular annulation using phenols and α-methoxy-β-ketoesters.
Ryo Miyata, Takashi Shigeta, Shigenori Kumazawa, Masahiro Egi   +3 more
doaj   +1 more source

Recent Applications of Quinolinium Salts in the Synthesis of Annulated Heterocycles

SynOpen, 2022
Quinoline derivatives are frequently found in natural products and biologically active compounds; however, construction of quinoline fused polyheterocycles is a challenging goal in synthetic organic chemistry.
Suven Das
doaj   +1 more source

Synthesis of 3-Hydroxy-9H-fluorene-2-carboxylates via Michael Reaction, Robinson Annulation, and Aromatization

Organics, 2022
A series of 3-hydroxy-fluorene-2-carboxylate compounds were prepared from Michael addition of acetoacetate to 2-benzylideneindan-l-one followed by Robinson annulation and aromatization.
Yu-Min Wang, Yi-Hung Liu, Shiuh-Tzung Liu   +2 more
doaj   +1 more source

The [3+2] Annulation of CF3-Ketimines by Re Catalysis: Access to CF3-Containing Amino Heterocycles and Polyamides

iScience, 2020
Summary: Transition metal catalyzed [3 + 2] annulation of imines with double bonds via directed C-H activation offers a direct access to amino cyclic motifs.
Saisai Zhang, Xun-Yong Liu, Zhenbang Chang, Xinxin Qiao, Heng-Ying Xiong, Guangwu Zhang   +5 more
doaj   +1 more source

A Zinc-Mediated Deprotective Annulation Approach to New Polycyclic Heterocycles

Molecules, 2021
A straightforward approach to new polycyclic heterocycles, 1H-benzo[4,5]imidazo[1,2-c][1,3]oxazin-1-ones, is presented. It is based on the ZnCl2-promoted deprotective 6-endo-dig heterocyclization of N-Boc-2-alkynylbenzimidazoles under mild conditions ...
Lucia Veltri, Roberta Amuso, Marzia Petrilli, Corrado Cuocci, Maria A. Chiacchio, Paola Vitale, Bartolo Gabriele   +6 more
doaj   +1 more source

Rapid and practical access to diverse quindolines by catalyst-free and regioselectivity-reversed Povarov reaction

Cell Reports Physical Science, 2021
Summary: The Povarov reaction, a formal [4 + 2] cycloaddition between N-aryl imines and electron-rich dienophiles, has been defined as an efficient method to approach tetrahydroquinolines and has been well established in the past decades.
Ying-Qi Zhang, Yi-Ping Zhang, Yan-Xin Zheng, Zhao-Yang Li, Long-Wu Ye   +4 more
doaj   +1 more source

A Review on Generation and Reactivity of the N-Heterocyclic Carbene-Bound Alkynyl Acyl Azolium Intermediates

Molecules, 2022
N-heterocyclic carbene (NHC) has been widely used as an organocatalyst for both umpolung and non-umpolung chemistry. Previous works mainly focus on species including Breslow intermediate, azolium enolate intermediate, homoenolate intermediate, alkenyl ...
Ziyang Dong, Chengming Jiang, Changgui Zhao   +2 more
doaj   +1 more source