Indole-Fused Benzoxepine Synthesis via Visible-Light-Driven Aerobic Dehydrogenative [5+2] Annulation

Article Chemistry, Multidisciplinary

Asymmetric (4+n) Cycloadditions of Indolyldimethanols for the Synthesis of Enantioenriched Indole‐Fused Rings

Jia-Yi Zhang et al.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2023)

Article Chemistry, Multidisciplinary

Palladium-catalyzed annulative allylic alkylation for regioselective construction of indole-fused medium-sized cyclic ethers

Ling-Qi Chen et al.

Summary: A new palladium-catalyzed annulative allylic alkylation reaction has been developed for the regioselective synthesis of tetracyclic cyclic ethers with bridged aryl-indole scaffolds.

CHINESE CHEMICAL LETTERS (2023)

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Article Chemistry, Organic

Ansafurantrienins, Unprecedented Ansatrienin Derivatives Formed via Photocatalytic Intramolecular [3+2] Oxidative Cycloaddition

Hongji Li et al.

Summary: This study isolated a series of Ansafurantrienins with unique structures from Streptomyces flaveolus. The structures, particularly the dihydrofuran unit, were determined using spectroscopic analyses, molecular modeling, and TDDFT/ECD calculations. It was found that these compounds exhibited significant antiproliferative effects against pancreatic cancer cells, highlighting their potential in cancer treatment.

ORGANIC LETTERS (2022)

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Article Chemistry, Physical

Catalytic Oxidative Coupling of Phenols and Related Compounds

Jingze Wu et al.

Summary: This Perspective provides an overview of catalytic methods for the oxidative coupling of phenols, focusing on the last 10 years, and summarizes current challenges.

ACS CATALYSIS (2022)

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Article Chemistry, Organic

Rhodium-Catalyzed Annulation of Vinylated Tyrosines with Internal Alkynes to Access Oxepine-Mounted Unnatural Tyrosines and Its Peptide Late Stage Functionalization

Narendra Dinkar Kharat et al.

Summary: A Rh(III)-catalyzed [5+2] annulation reaction was performed to successfully synthesize oxepine-mounted tyrosine-based unnatural amino acids by reacting vinyl tyrosines with symmetrical and unsymmetrical internal alkynes. The chemical applicability of this strategy was demonstrated through the stapling of amino acid/peptide-appended alkynes with vinyl tyrosines, as well as the late stage functionalization of tyrosine-containing dipeptides and tripeptides with internal alkynes.

ORGANIC LETTERS (2022)

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Review Chemistry, Organic

Recent advances in catalytic oxidative reactions of phenols and naphthalenols

Muhammad Adnan Bashir et al.

Summary: Oxidative reactions provide an effective strategy for phenol transformations via quinone intermediates. The structural diversity and sustainable accessibility of quinones still need further exploration.

ORGANIC CHEMISTRY FRONTIERS (2022)

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Review Chemistry, Organic

The synthesis of seven- and eight-membered rings by radical strategies

Xuan-Chi Yu et al.

Summary: Seven- and eight-membered rings are commonly found in natural products and drugs. Their synthesis is challenging due to transition state nonbonding interactions, torsional strains, flexible conformations, and complex multi-ring skeletons. The radical strategy, using metal-induced, oxidant-initiated, electrochemically promoted, or photoinduced systems, offers a powerful tool to overcome the limitations of poor selectivity and harsh reaction conditions. This review highlights recent advances in the synthesis of seven- and eight-membered rings and provides insights into exploring new reaction models in radical chemistry.

ORGANIC CHEMISTRY FRONTIERS (2022)

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Article Chemistry, Multidisciplinary

Electrooxidative Rhodium-Catalyzed [5+2] Annulations via C-H/O-H Activations

Yulei Wang et al.

Summary: The study introduces the first electrochemical metal-catalyzed [5+2] cycloadditions, assembling seven-membered benzoxepine skeletons with a high substrate scope and efficiency. The mechanistic studies support a rhodium(III/I) regime involving a benzoxepine-coordinated rhodium(I) sandwich complex as the catalyst resting state.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2021)

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Article Chemistry, Organic

Synthesis of Indole-Fused Oxepines via C-H Activation Initiated Diastereoselective [5+2] Annulation of Indoles with 1,6-Enynes

Xiaoli Huang et al.

Summary: A rhodium-catalyzed diastereoselective formal [5 + 2] annulation of indoles with cyclohexadienone-containing 1,6-enynes has been successfully established via indole 2,3-difunctionalization. This method allows for rapid construction of indole-fused oxepines with a broad substrate scope and simultaneous formation of cis-hydrobenzo[b] oxepine scaffolds, which are core units found in natural products with important biological activities.

ORGANIC LETTERS (2021)

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Article Multidisciplinary Sciences

Pharmaceutically relevant (hetero)cyclic compounds and natural products from lignin-derived monomers: Present and perspectives

Anastasiia Afanasenko et al.

Summary: Lignin, as the richest source of renewable aromatics on Earth, holds great potential for efficient depolymerization methods to produce specific monophenol derivatives, providing a foundation for downstream conversion strategies towards a wide range of products. The inherent structural features of lignin-derived platform chemicals inspire novel synthetic routes for the production of biologically active molecules or natural products. Efforts are being made to develop entire value-chains from wood to valuable pharmaceutically relevant compounds.

ISCIENCE (2021)

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Article Chemistry, Organic

Formal (3+4)-Annulation of Propargylic p-Quinone Methides with 2-Indolylmethanols: Synthesis of Polysubstituted Indole-Fused Oxepines

Zong-Wang Qiu et al.

Summary: A novel Bronsted acid catalyzed (3 + 4)-annulation method has been developed for the synthesis of polysubstituted indole-fused oxepines with high yields. This method explores the use of 2-indolylmethanols as four-atom synthons for the first time under Bronsted acid conditions.

JOURNAL OF ORGANIC CHEMISTRY (2021)

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Review Chemistry, Multidisciplinary

Turning the Light on Phenols: New Opportunities in Organic Synthesis

Beatrice Bartolomei et al.

Summary: Phenols and their corresponding electron-rich anions, phenolates, exhibit interesting physicochemical properties upon light excitation, becoming strong reducing agents and generating reactive radicals. They can trigger strategic bond-forming reactions, including direct aromatic C-H functionalization, and act as photocatalysts for organic transformations, leading to the development of a wide range of relevant organic reactions in the field of organic synthesis.

CHEMISTRY-A EUROPEAN JOURNAL (2021)

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Review Chemistry, Organic

Oxidative dehydrogenative couplings of alkenyl phenols

William C. Neuhaus et al.

Summary: Nature utilizes alkenyl phenols in the construction of lignin, a key biopolymer, leading to the formation of various structures like lignans and neolignans through selective dimerization. Several methods have been developed to influence desired bond formations in these biologically relevant scaffolds, with the most biomimetic involving oxidative bond formation via dehydrogenative coupling. This review discusses progress in the synthesis of important molecules derived from alkenyl phenols, while also recognizing existing gaps and limitations in current research.

ORGANIC & BIOMOLECULAR CHEMISTRY (2021)

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Article Chemistry, Multidisciplinary