Palladium‐Catalyzed Site‐Selective C(sp2)−H Acetoxylation of Tyrosine‐Containing Peptides

The site-selective modification of peptides in a tailored fashion represents a challenging task of prime interest in chemical biology and organic synthesis. We strategically transform the phenol ring within Tyr into a chelating group to further direct a C−H acetoxylation event. As a result, acetoxylation occurs regardless of the Tyr unit position within...

10h

Carpet Beater Molecules: Synthesis and Characterization of Functional Hexa‐peri‐benzocoronene–Alkyne Coupling Products

A library of nine HBC-alkyne hybrids with enlarged π-systems is presented. The iodide HBC served as a very suitable starting material for double Sonogashira reactions with several phenyl- or quinoxaline-based coupling partners. Spectroscopic analyses were performed and discussed as the varied substitution pattern changed the optoelectronic properties....

2d

Strapped Porphyrins as Model Systems for Atropisomeric Photosensitizer Drugs

Tetrapyrrole shape and distribution of polar substituents have been established as important design considerations for novel photosensitizers. Such parameters were successfully incorporated into the design of novel porphyrins with isomer specific cell internalization. Restrictive strapped moieties were used to enforce the α4 picket fence porphyrin motif...

2d

Structural Reassignment of Two Polyenol Natural Products

Chemical principles together with CASE and DFT methods were used to reassign unusual polyenols as nucleosides. Abstract Unusual polyenols that defied chemical principles were reassigned as the nucleosides, adenosine and uridine, using a combination of chemical intuition underpinned by Computer Assisted Structure Elucidation (CASE) and DFT methods.

2d

Construction of a Bifunctional Pd(0)‐CALB@SiO2 Hybrid Catalyst for the Synthesis and Arylation of Imidazo[1,2‐a]pyridine in One‐pot

The area of combining bio- and chemo-catalysis to construct organic molecules has seen tremendous progress in recent years. In this context, enzyme-metal biohybrid catalysts, combining the advantages of both enzymatic and metal catalysis, provide excellent opportunities to develop novel chemo-enzymatic reactions in a single pot. Herein, we describe...

2d

Catalyst‐Free, Heating‐Induced Desulfurization Annulation of CF3‐Imidoyl Sulfoxonium Ylides with Isothiocyanates for the Synthesis of 2‐Trifluoromethyl‐4‐aminoquinolines

A heating-induced desulfurization annulation of readily available CF3−imidoyl sulfoxonium ylides and isothiocyanates for the construction of 2-trifluoromethylquinolines has been achieved. The developed transformation was performed under metal- and additive-free conditions, producing a variety of biologically valuable 2-trifluoromethylquinoline derivatives...

2d

Transition‐Metal‐Free One‐Pot [3 + 3] Heteroannulative Coupling of Thioamides with Epichlorohydrin: Access to Diverse 1,3‐Thiazinanes

An operationally simple and efficient cascade approach to access a series of 1,3-thiazinanes has been developed via intermolecular [3+3] heteroannulative coupling employing β-ketothioamide as a C1N1S1 unit and epichlorohydrin as a C3 unit at room temperature for the first time. The reaction proceeds by nucleophilic attack of thiocarbonyl sulfur to less...

3d

Iodine and Iodide in Reductive Transformations

This review covers various strategies and methodologies for reducing C−O and heteroatomic−oxygen bonds (N−O, S−O, P−O) using I2/I−, as well as other synthetically relevant bonds such as C−C, N−N, C−N, C−X, and C−S. It discusses the mechanistic details provided by the original authors and includes examples of other halides (Br and Cl) as reductants....

3d

Tailoring the Chemical Structure of Cellulose Nanocrystals by Amine Functionalization

The surface functionalization of cellulose nanocrystals is presently considered a useful and straightforward tool for accessing very reliable biocompatible and biodegradable nanostructures with tailored physical and chemical properties. However, to date the fine characterization of the chemical appendages introduced onto cellulose nanocrystals remains...

3d

First Total Synthesis of the Benzotropolone/Bis(pulvinone) Natural Product Aurantricholone Exploiting New Strategies for Establishing Benzotropolones and Z‐Configured Pulvinones

The fungal colorant aurantricholone was synthesized in 15 steps. Its benzotropolone core resulted from 5-bromo-7,8-dimethoxytetral-1-one in 3 steps which included a 1-pot ring-enlargement/oxidation/acetylation sequence. A regioselective 2-step bromination allowed two Z-selective Suzuki couplings with a new tetronate building block to ensue in one go....

4d