Palladium‐Catalyzed Carbonylative Difunctionalization of C=N Bond of Azaarenes or Imines to Quinazolinones

"One pot" synthesis of quinazolinone-[2,3]-fused polycyclic scaffolds in a three-step reaction sequence

Diverse quinazolinone-[2,3]-fused polycyclic skeletons occupy a prominent position in drug discovery. Even with currently available methods there still remain unmet needs for flexible access to such structures. Herein, we have explored a mild "one pot" procedure for the construction of various quinazolinone-[2,3]-fused polycycles. The procedure involves Pd-catalyzed carbonylation of N-(2-iodophenyl)acetamides, release of the masked terminal amine, and two sequential and spontaneous cyclizations. This generally applicable approach features easy assembly of precursors from readily available starting materials, mild reaction conditions, non-cumbersome operation, and polycyclic diversity.

Synthesis of 2,3-Fused Quinazolinones via the Radical Cascade Pathway and Reaction Mechanistic Studies by DFT Calculations

An efficient radical cascade cyclization of unactivated alkenes toward the synthesis of a series of ring-fused quinazolinones has been developed in moderate to excellent yields using commercially available ethers, alkanes, and alcohols, respectively, under a base-free condition in a short time without a transition metal as catalyst. Notably, the transformations can be carried out with the advantages of a broad substrate scope and high atomic economy. Density functional theory calculations and wavefunction analyses were performed to elucidate the radical reaction mechanism.

Pd(II)-Catalyzed Cascade Annulation of o-Aminobenzoic Acids with CO, Amines, and Aldehydes to N3-/N1,N3-Substituted 2,3-Dihydroquinazolin-4(1H)-ones

The unprecedented Pd(II)-catalyzed cascade annulation of o-aminobenzoic acids with CO, amines, and aldehydes has been developed. This protocol provides an efficient and concise approach to selective construction of N3-substituted and N1,N3-disubstituted 2,3-dihydroquinazolin-4(1H)-ones mostly in moderate to excellent yields from simple and easily available starting materials under mild conditions featured with low cost, high step economy, broad substrate scope, and good product diversity.

Pd-Catalyzed carbonylative lactonization of 2-halidearomatic aldehydes with H2O as a nucleophile

A palladium-catalyzed carbonylative cyclization reaction of 2-halidebenzaldehydes with H₂O is described, which provides a strategy for the synthesis of diversely substituted 3,3'-oxyphthalides. Notably, the obtained 3,3'-oxyphthalide could be easily transformed into 3-aryl and alkyl phthalides with excellent efficiency using organozinc reagents under mild reaction conditions.

Iodine-Mediated C═C Double Bond Cleavage toward Pyrido[2,1-b]quinazolinones

A transition-metal-free C═C double bond cleavage reaction employing molecular iodine is described. In the presence of K₂CO₃ as the base, I₂-mediated C═C bond cleavage followed by intramolecular annulation of N-(2-vinylaryl)pyridin-2-amine substrates produces pyrido[2,1-b]quinazolinones and related heterocyclic compounds. This reaction can be completed on a gram scale and has been successfully applied to the synthesis of compounds with important biological properties, including efflux pump inhibitory and antiallergic activities.

Synthesis of pyrimidine-containing alkaloids

This review deals with the synthesis of naturally occurring alkaloids containing partially or completely saturated pyrimidine nuclei. The interest in these compounds is associated with their structural diversity, high biological activity and toxicity. The review is divided into four parts, each of which describes a number of synthetic methodologies toward structurally different naturally occurring alkaloids containing saturated cyclic six-membered amidine, guanidine, aminal and urea (thiourea) moieties, respectively. The development of various synthetic strategies for the preparation of these compounds has remarkably increased during the past few decades. This is primarily due to the fact that some of these compounds are isolated only in limited quantities, which makes it practically impossible to study their full structural characteristics and biological activity.

Recent Advances on the Synthesis of 2,3-Fused Quinazolinones

As one of the most important structural units in pharmaceuticals and medicinal chemistry, quinazolinone and its derivatives exhibit a wide range of biological and pharmacological activities, including anti-inflammatory, antitubercular, antiviral,...

The Synthesis, Structural Modification and Mode of Anticancer Action of Evodiamine: a review

BACKGROUND

Finding novel antitumor reagents from naturally occurring alkaloids is a widely accepted strategy. Evodiamine, a tryptamine indole alkaloid isolated from Evodia rutaecarpa, has a wide range of biological activities, such as antitumor, anti-inflammation, and anti-bacteria. Hence, research works on the structural modification of evodiamine will facilitate the discovery of new antitumor drugs.

OBJECTIVE

The recent advances in the synthesis of evodiamine, and studies on the drug design, biological activities, and structure-activity-relationships of its derivatives, published in patents and primary literatures, are reviewed in this paper.

METHODS

The literatures, including patents and follow-up research papers from 2015 to 2020, related to evodiamine is searched in the Scifinder, PubMed, Espacenet, China National Knowledge Infrastructure (CNKI), and Wanfang databases. The key words are evodiamine, synthesis, modification, anticancer, mechanism.

RESULTS

The synthesis of evodiamine are summarized. Then, structural modifications of evodiamine are described, and the possible modes of actions are discussed.

CONCLUSION

Evodiamine has a 6/5/6/6/6 ring system, and the structural modifications are focused on ring A, D, E, C5, N-13, and N-14. Some compounds show promising anticancer potentials and warrant further study.

Palladium-Catalyzed Tandem Carbonylative Diels-Alder Reaction for Construction of Bridged Polycyclic Skeletons

A palladium-catalyzed tandem carbonylative lactonization and Diels-Alder cycloaddition reaction between aldehyde-tethered benzylhalides and alkenes has been developed. A range of alkenes and aldehyde-tethered benzylhalides bearing different substituents can be successfully transformed into the corresponding bridged polycyclic compounds in good yields. This strategy provides a unique approach to complex lactone-containing bridged polycyclic compounds.

Palladium-catalyzed dearomative cyclocarbonylation of allyl alcohol for the synthesis of quinolizinones

An approach for the synthesis of quinolizinone with potential bioactivity has been developed via palladium-catalytic dearomative cyclocarbonylation of allyl alcohol. Diverse quinolizinone compounds could be attained with good efficiencies. A feasible reaction pathway could be a successive procedure of allylation, dearomatization, CO insertion and the Heck reaction.

Ligand-Controlled Copper-Catalyzed Regiodivergent Carbonylative Synthesis of α-Amino Ketones and α-Boryl Amides from Imines and Alkyl Iodides

Regioselective transformation is among the long-standing challenges in organic synthesis. In this communication, a copper-catalyzed selectivity controlled regiodivergent borocarbonylation of imines with alkyl iodides has been developed. Various α-amino ketones and α-boryl amides were produced in moderate to good yields from the same substrates. The choice of the ligand is key for the regioselectivity control: α-amino ketones were produced selectively in good yields with (p-CF₃ C₆ H₄ )₃ P as the ligand, whereas the corresponding α-boryl amides were obtained with high regioselectivities when using ^Me IMes as the ligand.

Rhodium(iii)-catalyzed annulation of 3-arylquinazolinones with alkynes via double C–H activation: an efficient route for quinolino[2,1-b]quinazolinones

An effective method for the synthesis of quinolino[2,1-b]quinazolinones has been described.

Constructing chiral aza-quaternary carbon centers by enantioselective carbonylative Heck reaction of o-iodoanilines with allenes

The construction of chiral aza-quaternary C-centers via C–N bond formation is achieved by a Pd-catalysed asymmetric carbonylative Heck reaction of o-iodoanilines with allenes, providing chiral dihydroquinolinone derivatives with moderate to high yield and enantiomeric ratio.