A Catalytic Approach for the Synthesis of Peptide-Oligonucleotides Conjugates in Aqueous Solution or On-Column.

Peptide-oligonucleotide conjugates (POCs) are covalent architectures composed of a DNA or RNA molecules linked to a peptide. These constructs have found widespread applications ranging from hybrid nanomaterials to gene-targeted therapies. Considering the important role of POCs, a new catalytic approach for their preparation is reported here, that could be applied either on solid support in anhydrous media, or post-synthetically in aqueous buffer.

Insights from structure-activity relationships and the binding mode of peptidic α-ketoamide inhibitors of the malaria drug target subtilisin-like SUB1.

Plasmodium multi-resistance, including against artemisinin, seriously threatens malaria treatment and control. Hence, new drugs are urgently needed, ideally targeting different parasitic stages, which are not yet targeted by current drugs. The SUB1 protease is involved in both hepatic and blood stages due to its essential role in the egress of parasites from host cells, and, as potential new target, it would meet the above criteria.

New biomaterials for Ni biosorption turned into catalysts for Suzuki-Miyaura cross coupling of aryl iodides in green conditions.

In parallel with increasing Ni production and utilisation, Ni pollution in the soil-water continuum has become an alarming and global problem. Solutions for removing Ni from industrial effluents have been widely investigated and biosorption has emerged as an efficient, cost-effective, scalable and sustainable alternative for water treatment. However, the biosorption capacity is limited by the chemical composition of the biomaterial and the Ni-enriched biomaterials are rarely valorised.

Unified Approach to the Chemoselective α-Functionalization of Amides with Heteroatom Nucleophiles.

Functionalization at the α-position of carbonyl compounds has classically relied on enolate chemistry. As a result, the generation of a new C-X bond, where X is more electronegative than carbon requires an oxidation event. Herein we show that, by rendering the α-position of amides electrophilic through a mild and chemoselective umpolung transformation, a broad range of widely available oxygen, nitrogen, sulfur, and halogen nucleophiles can be used to generate α-functionalized amides.

α-Fluorination of carbonyls with nucleophilic fluorine.

Given the unique properties of fluorine, and the ability of fluorination to change the properties of organic molecules, there is significant interest from medicinal chemists in innovative methodologies that enable the synthesis of new fluorinated motifs. State-of-the-art syntheses of α-fluorinated carbonyl compounds invariably rely on electrophilic fluorinating agents, which can be strongly oxidizing and difficult to handle. Here we show that reversing the polarity of the enolate partner to that of an enolonium enables nucleophilic fluorinating agents to be used for direct chemoselective α-C-H-fluorination of amides.

Chemoselective α,β-Dehydrogenation of Saturated Amides.

We report a method for the selective α,β-dehydrogenation of amides in the presence of other carbonyl moieties under mild conditions. Our strategy relies on electrophilic activation coupled to in situ selective selenium-mediated dehydrogenation. The α,β-unsaturated products were obtained in moderate to excellent yields, and their synthetic versatility was demonstrated by a range of transformations.

Chemoselective Activation of Diethyl Phosphonates: Modular Synthesis of Biologically Relevant Phosphonylated Scaffolds.

Phosphonates have garnered considerable attention for years owing to both their singular biological properties and their synthetic potential. State-of-the-art methods for the preparation of mixed phosphonates, phosphonamidates, phosphonothioates, and phosphinates rely on harsh and poorly selective reaction conditions. We report herein a mild method for the modular preparation of phosphonylated derivatives, several of which exhibit interesting biological activities, that is based on chemoselective activation with triflic anhydride.

Chemoselective Intermolecular Cross-Enolate-Type Coupling of Amides.

A new approach for the synthesis of 1,4-dicarbonyl compounds is reported. Chemoselective activation of amide carbonyl functionality and subsequent umpolung via N-oxide addition generates an electrophilic enolonium species that can be coupled with a wide range of nucleophilic enolates. The method conveys broad functional group tolerance on both components, does not suffer from formation of homocoupling byproducts and avoids the use of transition metal catalysts.

From acyclic to cyclic α-amino vinylphosphonates by using ring-closing metathesis.

Acyclic α-amino vinylphosphonates were alkylated through the Mitsunobu reaction then diolefinic compounds hence formed were subjected to RCM. Studies on the scope and limitations of RCM with these sterically hindered α-amino vinylphosphonates are detailed.

Cerium(IV) ammonium nitrate mediated 5-endo-dig cyclization of α-amino allenylphosphonates to spirodienones.

α-Amino allenylphosphonates were treated with cerium(iv) ammonium nitrate under various conditions to form spirodienones in good to excellent yields. The 5-endo-dig cyclization proceeds through the formation of a key iminium intermediate. A comprehensive study on the nature of the solvent used for this reaction was undertaken resulting in the formation of three types of spirodienone scaffolds.

Designing dye-nanochannel antenna hybrid materials for light harvesting, transport and trapping.

We discuss artificial photonic antenna systems that are built by incorporating chromophores into one-dimensional nanochannel materials and by organizing the latter in specific ways. Zeolite L (ZL) is an excellent host for the supramolecular organization of different kinds of molecules and complexes. The range of possibilities for filling its one-dimensional channels with suitable guests has been shown to be much larger than one might expect.