Complementary Site-Selective Sulfonylation of Aromatic Amines by Superacid Activation

International audienceUnder superacidic conditions, aniline and indole derivatives are sulfonylated at low temperature with easy-to-access arenesulfonic acids or arenesulfonyl hydrazides. By modification of the functional-group directing effect through protonation, this method allows nonclassical site functionalization by overcoming the innate regioselectivity of electrophilic aromatic substitution. This superacid-mediated sulfonylation of arenes is complementary to existing methods and can be applied, through protection by protonation, to the late-stage site-selective functionalization of natural alkaloids and active pharmaceutical ingredients

Enantioselective Organocatalysis and Superacid Activation: Challenges and Opportunities

International audienceSince the pioneer reports of Akiyama and Terada groups on Brønsted acid organocatalysis, this field never stopped growing with the development of ingenious strategies for the activation of challenging poorly reactive substrates. The development of superacidic organocatalysts is an important way to selectively functionalize reluctant electrophiles and other approaches have also emerged such as the combination of Lewis and Brønsted acids as well as the consecutive organocatalysis and superacid activation. This concept aims to highlight these different strategies and demonstrate their complementarity

High efficiency of superacid HF-SbF5 for the selective decrystallization-depolymerization of cellulose to glucose.

International audienceHerein, we show that after polyprotonation, superacid HF-SbF(5) is able to selectively depolymerise cellulose to water-soluble carbohydrates with 68 wt% yield of glucose. This process is efficient at low temperature, thus avoiding the formation of side products as commonly observed with conventional acids

Enantioselective Organocatalysis and Superacid Activation: Challenges and Opportunities

Abstract Since the pioneer reports of the groups of Akiyama and Terada on Brønsted acid organocatalysis, this field never stopped growing with the development of ingenious strategies for the activation of challenging poorly reactive substrates. The development of superacidic organocatalysts is an important way to selectively functionalize reluctant electrophiles and other approaches have also emerged such as the combination of Lewis and Brønsted acids as well as the consecutive organocatalysis and superacid activation. This Concept aims to highlight these different strategies and demonstrate their complementarity

CF -substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

International audience“The extraordinary instability of such an “ion” accounts for many of the peculiarities of organic reactions” – Franck C. Whitmore (1932). This statement from Whitmore came in a period where carbocations began to be considered as intermediates in reactions. Ninety years later, pointing at the strong knowledge acquired from the contributions of famous organic chemists, carbocations are very well known reaction intermediates. Among them, destabilized carbocations – carbocations substituted with electron-withdrawing groups – are, however, still predestined to be transient species and sometimes considered as exotic ones. Among them, the CF3-substituted carbocations, frequently suggested to be involved in synthetic transformations but rarely considered as affordable intermediates for synthetic purposes, have long been investigated. This review highlights recent and past reports focusing on their study and potential in modern synthetic transformations

Modulating the Efficacy of Carbonic Anhydrase Inhibitors through Fluorine Substitution

International audienceThe insertion of fluorine atoms and/or fluoroalkyl groups can lead to many beneficial effects in biologically active molecules, such as enhanced metabolic stability, bioavailability, lipophilicity, and membrane permeability, as well as a strengthening of protein–ligand binding interactions. However, this “magic effect” of fluorine atom(s) insertion can often be meaningless. Taking advantage of the wide range of data coming from the quest for carbonic anhydrase (CA) fluorinated inhibitors, this Minireview attempts to give “general guidelines” on how to wisely insert fluorine atom(s) within an inhibitor moiety to precisely enhance or disrupt ligand–protein interactions, depending on the target location of the fluorine substitution in the ligand. Multiple approaches such as ITC, kinetic and inhibition studies, X-ray crystallography, and NMR spectroscopy are useful in dissecting single binding contributions to the overall observed effect. The exploitation of innovative directions made in the field of protein and ligand-based fluorine NMR screening is also discussed to avoid misconduct and finely tune the exploitation of selective fluorine atom insertion in the futur

Direct and Selective C-H Carbamoylation of (Hetero)aromatics with TMSOTf-Activated Carbamoyl Chloride

International audienc

Stereoselective Hydrofluorination of Ynamides: a Straightforward Synthesis of Novel alpha-Fluoroenamides

alpha-Fluoroenamides, potent rigid fluorinated bioisosters of ureas,have been synthesized by a highly regio- and stereo-selective hydrofluorination of ynamides in anhydrous HF. This reaction provides the first general entry to alpha-fluoroenamides and can easily be applied to a wide range of substrates.SCOPUS: ar.jinfo:eu-repo/semantics/publishe