Asymmetric Catalytic [4+5] Annulation of ortho-Quinone Methides with Vinylethylene Carbonates and its Extension to Stereoselective Tandem Rearrangement.

Chemistry

State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou, 730000, China.

Published: March 2020

Palladium-catalyzed asymmetric [4+5] annulation of ortho-quinone methides (o-QMs) with substituted vinylethylene carbonates (VECs) is described for the first time, giving a novel enantioselective approach to chiral nine-membered benzoheterocycles. Based on this designed [4+5] annulation, an unprecedented silica gel-promoted tandem rearrangement reaction featuring a unique asymmetric aromatic Claisen rearrangement is explored at room temperature, offering a new method for asymmetric construction of all-carbon quaternary stereocenters embedded in chiral functionalized homoallylic alcohols.

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.201904903DOI Listing

Publication Analysis

Top Keywords

[4+5] annulation
12
annulation ortho-quinone
8
ortho-quinone methides
8
vinylethylene carbonates
8
tandem rearrangement
8
asymmetric
4
asymmetric catalytic
4
catalytic [4+5]
4
methides vinylethylene
4
carbonates extension
4

Similar Publications

A copper-catalyzed domino addition/cyclization reaction was developed to synthesize novel benzoselenazole-linked 1,2,3-triazole and tetracyclic fused 12-benzo[4,5]selenazole[2,3-]quinazolin-12-one derivatives from isoselenocyanates. This domino reaction efficiently constructed multiple new chemical bonds in a single step, forming either four (one C-Se and three C-) or three (one C-Se and two C-) bonds. The reaction offers several key advantages, including mild conditions, broad substrate compatibility, and straightforward and safe operation.

View Article and Find Full Text PDF

The first carbocyclic gallylene [(ADC)Ga(GaI)] and bis-gallylene [(ADC)Ga] (ADC = PhC{N(Dipp)C}; Dipp = 2,6-iPrCH) featuring a central CGa ring annulated between two 1,3-imidazole rings are prepared by KC reductions of [(ADC)GaI]. Treatment of [(ADC)Ga] with Fe(CO) affords complex [(ADC)GaFe(CO)] in which each Ga(i) atom serves as a two-electron donor. [(ADC)Ga] activates white phosphorus (P) and the C -F bond of aryl fluorides (ArF) to yield compounds [(ADC)Ga(P)] and -/-[(ADC)GaF(Ar)], respectively.

View Article and Find Full Text PDF

The electrochemically mediated cyanation/annulation process with in situ cyanide ion generation from NH4SCN and multi-step oxidative construction of CN-functionalized heterocycles from easily available α-amino esters and pyridine-2-carbaldehydes has been discovered. Depending on the nature of the α-amino ester, 1-cyano-imidazo[1,5-a]pyridine-3-carboxylates, 3-alkyl- and 3-aryl-imidazo[1,5-a]pyridines-1-carbonitriles, and the first reported 4-oxo-4H-pyrido[1,2-a]pyrazine-1-carbonitriles were obtained. The electrosynthesis is carried out in an undivided electrochemical cell under constant current conditions.

View Article and Find Full Text PDF

A streamlined strategy for the one-pot synthesis of isoxazolone analogues has been developed through an acceptorless dehydrogenative annulation (ADA) pathway by employing new Ru(II) hydride complexes as effective catalysts. New Ru(II) complexes () tailored with N̂O chelating carbazolone benzhydrazone ligands were synthesized and their formation was confirmed using analytical and spectral techniques including FT-IR and NMR. The structural configuration of the complexes featuring an octahedral geometry around the Ru(II) ion was precisely determined by single-crystal X-ray diffraction analysis.

View Article and Find Full Text PDF

Efficient synthesis of fluorinated triphenylenes with enhanced arene-perfluoroarene interactions in columnar mesophases.

Beilstein J Org Chem

December 2024

Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), F-67034 Strasbourg, France.

The high potential of non-covalent arene-fluoroarene intermolecular interactions in the design of liquid crystals lies in their ability to strongly promote self-assembly, improve the order and stability of the supramolecular mesophases, and enable tuneability of the optical and electronic properties, which can potentially be exploited for advanced applications in display technologies, photonic devices, sensors, and organic electronics. We recently successfully reported the straightforward synthesis of several mesogens containing four lateral aliphatic chains and derived from the classical triphenylene core self-assembling in columnar mesophases based on this paradigm. These mesogenic compounds were simply obtained in good yields by the nucleophilic substitution (SFAr) of various types of commercially available fluoroarenes with the electrophilic organolithium derivatives 2,2'-dilithio-4,4',5,5'-tetraalkoxy-1,1'-biphenyl (2Li- ).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!