Lewis Acid-Controlled Regioselectivity in Reactions of Styrenyl Systems with Benzoquinone Monoimides: New Regioselective Syntheses of Substituted 2-Aryl-2,3-dihydrobenzofurans, 2-Aryl-2,3-dihydroindoles, and 2-Arylindoles

Discovery of AL-GDa62 as a Potential Synthetic Lethal Lead for the Treatment of Gastric Cancer

Diffuse gastric cancer and lobular breast cancer are aggressive malignancies that are frequently associated with inactivating mutations in the tumor suppressor gene CDH1. Synthetic lethal (SL) vulnerabilities arising from CDH1 dysfunction represent attractive targets for drug development. Recently, SLEC-11 (1) emerged as a SL lead in E-cadherin-deficient cells. Here, we describe our efforts to optimize 1. Overall, 63 analogues were synthesized and tested for their SL activity toward isogenic mammary epithelial CDH1-deficient cells (MCF10A-CDH1^-/-). Among the 26 compounds with greater cytotoxicity, AL-GDa62 (3) was four-times more potent and more selective than 1 with an EC₅₀ ratio of 1.6. Furthermore, 3 preferentially induced apoptosis in CDH1^-/- cells, and Cdh1^-/- mammary and gastric organoids were significantly more sensitive to 3 at low micromolar concentrations. Thermal proteome profiling of treated MCF10A-CDH1^-/- cell protein lysates revealed that 3 specifically inhibits TCOF1, ARPC5, and UBC9. In vitro, 3 inhibited SUMOylation at low micromolar concentrations.

Synthesis of C3-alkylated benzofurans via palladium-catalyzed regiocontrolled hydro-furanization of unactivated alkenes

A new chelation-controlled hydrofuranization of unactivated olefins with α-alkynyl arylols is reported for the first time, and used to produce a wide range of C₃-alkylated benzofurans with generally good yields under mild conditions.

Ring contraction of N-acetyl-2-aryl-1,2,3,4-tetrahydro-4-quinolones with [hydroxy(tosyloxy)iodo]benzene to trans methyl N-acetyl-2-aryl-2,3-dihydroindol-3-carboxylates

The ring contraction of N-acetyl-2-aryl-1,2,3,4-tetrahydro-4-quinolones with [hydroxy(tosyloxy)iodo]benzene to trans methyl N-acetyl-2-aryl-2,3-dihydroindol-3-carboxylates in trimethylorthoformate in good yield is described.

E-Olefins through intramolecular radical relocation

Full control over the selectivity of carbon-carbon double-bond migrations would enable access to stereochemically defined olefins that are central to the pharmaceutical, food, fragrance, materials, and petrochemical arenas. The vast majority of double-bond migrations investigated over the past 60 years capitalize on precious-metal hydrides that are frequently associated with reversible equilibria, hydrogen scrambling, incomplete E/Z stereoselection, and/or high cost. Here, we report a fundamentally different, radical-based approach. We showcase a nonprecious, reductant-free, and atom-economical nickel (Ni)^(I)-catalyzed intramolecular 1,3-hydrogen atom relocation to yield E-olefins within 3 hours at room temperature. Remote installations of E-olefins over extended distances are also demonstrated.

Total synthesis of natural products containing benzofuran rings

In this review, various approaches for the construction of benzofurans as an important moiety in different natural products during the total synthesis of the natural of products are underscored.

Diastereo- and enantioselective construction of an indole-based 2,3-dihydrobenzofuran scaffold via catalytic asymmetric [3+2] cyclizations of quinone monoimides with 3-vinylindoles

The first catalytic asymmetric [3+2] cyclization of quinone monoimides with 3-vinylindoles has been established, which constructed a biologically important 2,3-dihydrobenzofuran framework in high stereoselectivities (up to >95 : 5 dr, 96 : 4 er).

Catalytic chemoselective [3+3] cycloadditions of azomethine ylides with quinone monoimides leading to the construction of a dihydrobenzoxazine scaffold

A chemoselective [3+3] cycloaddition of in situ generated azomethine ylides with quinone monoimides has been established, which efficiently led to the construction of dihydrobenzoxazine frameworks with biological relevance.

Synthesis of Pterocarpans

The total synthesis of natural pterocarpans and analogs is reviewed.

[3+2] versus [4+2] Cycloadditions of Quinone Monoimide with Azadienes: A Lewis Acid-Free Access to 5-Amino-2,3-dihydrobenzofuranes

The reaction between p-quinone monoimide 1a and various azadienes 2 is described in the absence of a Lewis acid promoter. When alpha,beta-unsaturated hydrazones are substituted by proton or alkyl groups, 2,3-dihydrobenzofuranes 4, a motif that is present in numerous biologically active products, are obtained in moderate to excellent yields. The regio- and stereoselectivity of this reaction has been proved by a complete NMR study, including 1H-15N correlations.

A Rapid Synthesis of 2-Aryl-5-substituted-2,3-dihydrobenzofurans

[reaction: see text] An effective strategy has been developed for the rapid and efficient one-pot synthesis of 2-aryl-5-substituted-2,3-dihydrobenzofurans from readily available o-nitrotoluenes and aromatic aldehydes. This strategy allows access to a structurally diverse array of products for further manipulation.

Synthesis of Neolignans from Anaxagorea Clavata

A synthesis of the neolognans (1) and (2) is described employing an intramolecular Wittig cyclisation to generate the 2-arylbenzofuran ring system.

Lewis acid promoted annulation of p-quinoneimines by allylsilanes: a facile entry into benzofused heterocycles

[reaction: see text] Lewis acid promoted addition of allyltriisopropylsilane to p-quinoneimines afforded different benzofused heterocycles in moderate to good yields depending on the conditions employed.