Etienne Derat

Sorbonne Université | UPMC · Institut Parisien de Chimie Moléculaire (IPCM)

Metallaphotoredox catalyzed cross-coupling of an arylbromide (Ar-Br) with an alkyl bis-catecholato silicate (R-Si⊖) has been analyzed in depth using a continuum of analytical techniques (EPR, fluorine NMR, electrochemistry, photophysics) and modeling (micro-kinetics and DFT calculations). These studies converged on the impact of four control parame...

We describe an efficient regio- and chemoselective dearomatization of N-heteroarenes using hydrido-cobalt catalysts. Reactions were performed under mild conditions on a wide range of N-heteroarenes leading exclusively to the silyl-1,2-dihydroheteroarene. Various quinolines and pyridines bearing electron-donating and electron-withdrawing substituent...

We introduce a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs-accelerated implementation within the Tinker-HP molecular dynamics package. We introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field.By adding harmonic...

We introduce a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs-accelerated implementation within the Tinker-HP molecular dynamics package. We introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field.By adding harmonic...

We detail a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs-accelerated implementation within the Tinker-HP molecular dynamics package. We then introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field. By adding harmo...

We detail a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs-accelerated implementation within the Tinker-HP molecular dynamics package. We then introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field. By adding harmo...

We detail a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs-accelerated implementation within the Tinker-HP molecular dynamics package. We then introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field. By adding harmo...

We detail a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs-accelerated implementation within the Tinker-HP molecular dynamics package. We then introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field. By adding harmo...

We detail a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUsaccelerated implementation within the Tinker-HP molecular dynamics package. We then introduce the new "dual-water" mode and its use with the flexible AMOEBA polarizable force field. By adding harmon...

The Cover Feature illustrates the dramatical effect of the phosphorous‐to‐palladium ratio in asymmetric Tsuji‐Trost allylation by using a 2,15‐bisphosphinite‐[6]‐helicene as the chiral ligand. It shows that like a tightrope walker′s pendulum that can swing to the right or left, the chemist can select the (R)‐enantiomer or the (S)‐enantiomer by vary...

We introduce a novel multi-level enhanced sampling strategy grounded on Gaussian accelerated Molecular Dynamics (GaMD). First, we propose a GaMD multi-GPUs -accelerated implementation within Tinker-HP. For the specific use with the flexible AMOEBA polarizable force field (PFF), we introduce the new "dual–water" GaMD mode. By adding harmonic boosts...

This article discloses a study on a chiral bis‐phosphorylated‐helical ligand in the palladium‐catalyzed Tsuji‐Trost allylation. The use of 2,15‐bisphosphinite[6]helicenes revealed a remarkable ligand effect, in which the (R) and (S) isomeric products can be selectively formed as a direct function of the amount of ligand introduced. Investigation of...

Erratum to J. Chem. Theory. Comput., 2019, 15, 3694-3709 (10.1021/acs.jctc.9b00199)

While the generation of aryl radicals by photoredox catalysis is well-documented under reductive conditions, it has remained challenging under an oxidative pathway. Because of the easy photooxidation of alkyl bis-catecholato silicates, a general study on phenyl silicates bearing substituted catecholate ligands has been achieved. The newly synthesiz...

This academic thought piece provides an overview of the history of, and current trends in, publishing practices in the scientific fields known to the authors (chemical sciences, social sciences and humanities), as well as a discussion of how open access mandates such as Plan S from cOAlition S will affect these practices. It begins by summarizing t...

In this chapter, the application of computational quantum mechanical methods to the understanding of radical reactions is introduced. For radical reactions, access to electronic configurations through quantum chemical calculations allows rationalization of unusual reactivities. Using the valence bond approach, the nature of bonding in three-electro...

Immobilization of polyoxometalates (POMs) onto oxides is relevant to many applications in the fields of catalysis, energy conversion/storage or molecular electronics. Optimization and understanding the molecule/oxide interface is crucial to rationally improve the performance of the final molecular materials. We herein describe the synthesis and cov...

Immobilization of polyoxometalates (POMs) onto oxides is relevant to many applications in the fields of catalysis, energy conversion/storage or molecular electronics. Optimization and understanding the molecule/oxide interface is crucial to rationally improve the performance of the final molecular materials. We herein describe the synthesis and cov...

Enallenes can be readily converted into two families of 3.2.0 (hetero)bicycles with high diastereoselectivities through the combination of visible light with a suitable Ir(III) complex (1 mol %). Two complementary pathways, namely, a photocycloaddition versus a radical chain, can then take place. Both manifolds grant complete regiocontrol of the al...

NHC-capped β-cyclodextrin (β-ICyD) was used as a ligand for gold-catalyzed alkoxycyclization reactions. The cavity was found to be responsible for a triple selectivity: (i) the asymmetric shape of the cavity of β-ICyD induced highly stereoselective cyclizations, (ii) the shape of the interior favored the formation of a six-membered ring in the abse...

Using polarizable (AMOEBA) and non-polarizable (CHARMM) force fields, we compare the relative free energy stability of two extreme conformations of the HIV-1 NCp7 nucleocapsid that had been previously experimentally advocated to prevail in solution. Using accelerated sampling techniques, we show that they differ in stability by no more than 0.75-1....

Hohl-in-One: Die Hohlraum-kontrollierte chemoselektive Kupfer-katalysierte 1,2- bzw. 1,4-Hydrosilylierung von α,β-ungesättigten Ketonen wurde in NHC-gedeckelten Cyclodextrinen (ICyDs) beobachtet. Im Hohlraum befindet sich eine seltene, intermediäre, monomere (L)CuH-Gruppe. Abstract The encapsulation of copper inside a cyclodextrin capped with an N...

The encapsulation of copper inside a cyclodextrin capped with a N ‐heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)Cu‐H and a cavity‐controlled chemoselective copper‐catalyzed hydrosilylation of α,β ‐unsaturated ketones. Remarkably, ( α ‐ICyD)CuCl promoted exclusively the 1,2‐addition, while ( β ‐ICyD)CuCl produced the to...

The design and synthesis of a supramolecular square composed of polyoxometalate-based hybrid donors and ethylenediamine palladium(II) nodes are reported. The structure of the metallomacrocycle scaffold was inferred by diffusion NMR, small-angle X-ray scattering (SAXS), and molecular modeling. The metallomacrocycle scaffold that contains negatively...

The Human Immunodeficiency Virus Type 1 nucleocapsid 7 (NCp7) is a multi-functional protein formed by N-terminal and C-terminal domains surrounding two Zn-fingers, linked by a stretch of basic residues, which play a key role in the viral replica-tion. We report the first NCp7 polarizable molecular dynamics (MD) study using the AMOEBA force field co...

The Human Immunodeficiency Virus Type 1 nucleocapsid 7 (NCp7) is a multi-functional protein formed by N-terminal and C-terminal domains surrounding two Zn-fingers, linked by a stretch of basic residues, which play a key role in the viral replica-tion. We report the first NCp7 polarizable molecular dynamics (MD) study using the AMOEBA force field co...

Nowadays, the quest of new radical precursors based on heteroatom complexes occupies an increasingly prominent position in contemporary research. Herein, we investigated the behavior and the limitations of hexa‐ or pentacoordinated organochlorosilanes and related pentacoordinated silyliums as new families of complexes for the generation of radicals...

The Catellani reaction is a multi-component cascade sequence, catalysed by palladium and norbornene, which typically uses aromatic starting materials. Now, through the use of a modified norbornene co-catalyst, the scope of this reaction has been extended to alkenyl reagents, enabling the preparation of all-carbon tetrasubstituted olefins.

Steered Molecular Dynamic (SMD) is a powerful technique able to accelerate rare events sampling in Molecular Dynamics (MD) simulations by applying an external force to a set of chosen atoms. Despite generating non-equilibrium simulations, SMD remains capable of reconstructing equilibrium properties such as the Potential of Mean Force (PMF). Of cour...

This paper is dedicated to the massively parallel implementation of Steered Molecular Dynamics in the Tinker-HP softwtare. It allows for direct comparisons of polarizable and non-polarizable simulations of realistic systems.

The synthesis, optical resolution through derivatization, characterization, and utilization of a new helical bis(phosphinite gold) complex derived from HELIXOL are described. By using an efficient cobalt catalyst, neither irradiation nor high catalytic loading was required to access the helicene of interest. The latter was phosphorylated to afford...

This work features the previously undescribed interactions of Martin’s spirosilane with different types of N-heterocyclic carbenes (NHCs). The level of interaction proved to be strongly dependent on the size of the Lewis base and could vary from the formation of isolable classical Lewis adducts to abnormal Lewis adducts, as evidenced by X-ray diffr...

An iron(II) borohydride complex ([(η¹-H3BH)FeCl(NCCH3)4]) is employed as the precatalyst in iron-catalyzed radical cyclizations of unsaturated organic halides in the presence of NaBH4. Mechanistic investigations have established that the ligand bound to the metal center (acetonitrile versus ethylenebis(diphenylphosphine) (dppe)) plays a crucial rol...

We present that cationic rings could act as donor ligands thanks to suitably delocalized metal-metal bonds. This could grant to parent complexes the peculiar properties of aromatic rings crafted with main group elements. We assembled Pd nuclei into equilateral mono-cationic triangles with unhindered faces. Like their main-group element counterparts...

2,2’,6,6’-tetraphenyl-4,4’-dipyranylidene (DIPO-Ph4) was grown by vacuum-deposition on an indium tin oxide (ITO) substrate. The films were characterized by atomic force microscopy and synchrotron radiation UV and X-ray photoelectron spectroscopy to gain an insight into the material growth and to better understand the electronic properties of the DI...

NHC-capped cyclodextrin (ICyD) ligands, α-ICyD and β-ICyD derived from α- and β-cyclodextrin respectively give opposite regioselectivities in a copper-catalyzed hydroboration. The site-selectivity results from two different mechanisms: the conventional "parallel" one and a new "orthogonal" mechanism. The shape of the cavity was shown not only to in...

NHC-capped cyclodextrin (ICyD) ligands, α-ICyD and β-ICyD derived from α- and β-cyclodextrin respectively give opposite regioselectivities in a copper-catalyzed hydroboration. The site-selectivity results from two different mechanisms: the conventional "parallel" one and a new "orthogonal" mechanism. The shape of the cavity was shown not only to in...

A series of capped metallo-cyclodextrins were synthesized, affording a variety of artificial chiral metallo-pockets through modulation of the space around the metal. Carbene ligands were used as caps to place a silver, gold or copper center at a well-defined location inside the cyclodextrin cavity. Multiple weak interactions involving the d10 metal...

Gold(I) catalyzed cycloisomerization of an enynyl propargylic ester, featuring a 1,2 acyloxy migration/intramolecular cyclopropanation sequence, opens a straightforward access to the 5,7,3 tricyclic skeletton of neomerane sesquiterpenes. The first total synthesis of 5-epi-valeneomerin B in 12 steps with an overall yield of 5.3% from the readily ava...

The back cover picture shows how, through a combination of calculations mixing quantum and molecular mechanics (as depicted by the code), the reactivation process of acetylcholinesterase inhibited by nerve agent can be better understood (enzyme shown as a ribbon). In particular, simulations demonstrate that an active-site glutamate is able to depro...

The photophysical properties of a Keggin-type polyoxometalate (POM) covalently bounded to a benzospiropyran (BSPR) unit have been investigated. These studies reveal that both closed and open forms are emissive with distinct spectral features (λem (closed form)=530 nm, λem (open form)=670 nm) and that the fluorescence of the BSPR unit of the hybrid...

The photophysical properties of a Keggin-type polyoxometalate (POM) covalently bounded to a benzospiropyran (BSPR) unit have been investigated. These studies reveal that both closed and open forms are emissive with distinct spectral features (λem (closed form)=530 nm, λem (open form)=670 nm) and that the fluorescence of the BSPR unit of the hybrid...

We report here on a new series of CO2-reducing molecular catalysts based on Earth-abundant elements that are very selective for the production of acid formic in DMF/water mixtures (Faradaic efficiency of 90±10%) at moderate overpotentials (500–700 mV in DMF measured at the middle of the catalytic wave). The [CpCo(PR2NR’2)I]+compounds contain diphos...

Acetylcholinesterase (AChE) is an enzyme of the serine hydrolase superfamily and a mediator of the signal transmission at cholinergic synapses catalysing acetylcholine cleavage into an acetate and a choline. This enzyme is vulnerable to covalent inhibition by organophosphate compounds (like VX). The covalent inhibition of AChE does not revert spont...

A method to obtain aryl nitriles from the corresponding halides by Pd catalysis, in the absence of any cyanide source, is reported. The reaction of an aryl halide, ethyl nitroacetate, and an olefin readily delivers an aromatic nitrile. A variety of aryl iodides/bromides have been converted into the corresponding cyanoarenes in fair to excellent yie...

Herein, the use of a well-defined low-valent cobalt(I) catalyst [HCo(PMe3)4] capable of performing the highly regio- and stereoselective hydrosilylation of internal alkynes is reported. The reaction can be applied to a variety of hydrosilanes, symmetrical and unsymmetrical alkynes, giving in many cases a single hydrosilylation isomer. Experimental...

The use of a well-defined low-valent cobalt complex for the functionalization of indoles in the absence of an external reductant or additives is described.

Herein an extremely versatile, well-defined, low-valent cobalt catalyst [Co(PMe3)4] capable of intermolecular and intramolecular imine-directed C2-alkylation and alkenylation of indoles is reported. The reaction proceeds in the absence of reducing agents or additives, affording a range of substituted indoles and dihydropyrroloindoles in high yields...

A well-defined copper complex bearing iminosemiquinone ligands performs single electron reduction of an electrophilic CF3+ source into CF˙3 radicals. This redox behavior is enabled by the ligand which shuttles through two different redox states (iminosemiquinone and iminobenzoquinone) while the copper center is preserved as a Cu(II). This system wa...

A polyoxometalate-based molecular triangle has been synthesized through the metal-driven self-assembly of covalent organic/inorganic hybrid oxo-clusters with remote pyridyl binding sites. The new metallomacrocycle was unambiguously characterized by using a combination of (1) H NMR spectroscopy, 2D diffusion NMR spectroscopy (DOSY), electrospray ion...

A convenient one-pot system has been developed, allowing the synthesis of highly substituted dihydropyridines via a C-H activation/6π-electrocyclization pathway. The reaction proceeds with high regioselectivity, and we disclose the first example of isolated dihydropyridines lacking substitution in the 2 position. Moreover, the use of a simple well-...

A molybdenum-dithiolene-oxo complex was prepared as a model of some active sites of Mo/W-dependent enzymes. The ligand, a quinoxaline-pyran-fused dithiolene, mimics molybdopterin present in these active sites. For the first time, this type of complex was shown to be active as a catalyst for the photoreduction of protons with excellent turnover numb...

This works introduces hypervalent bis-catecholato silicon compounds as versatile sources of alkyl radicals upon visible-light photocatalysis. Using Ir[(dF(CF3 )ppy)2 (bpy)](PF6 ) (dF(CF3 )ppy=2-(2,4-difluorophenyl)-5-trifluoromethylpyridine, bpy=bipyridine) as catalytic photooxidant, a series of alkyl radicals, including highly reactive primary one...

A collection of phosphine oxide allenes has been prepared. Their coordination to gold(I) has been studied giving new coordination complexes when a pendant pyridine moiety was present. Alternatively, their gold(I)‐catalyzed cycloisomerization has proven to be quite efficient. An almost complete axial‐to‐central chirality transfer in the cyclization...

This article proposes to bridge two fields, namely organometallics and quantum chemical topology. To do so, Palladium-catalyzed reductive elimination is studied. Such reaction is a classical elementary step in organometallic chemistry, where the directionality of electrons delocalization is not well understood. New computational evidences highlight...

The development of new energy storage technologies is central to solving the challenges facing the widespread use of renewable energies. An option is the reduction of carbon dioxide (CO2) into carbon-based products which can be achieved within an electrochemical cell. Future developments of such processes depend on the availability of cheap and sel...

A facile C-H activation and functionalization of aromatic imines is presented using low-valent cobalt catalysts. Using Co(PMe3)4 as catalyst we have developed an efficient and simple protocol for the C-H/hydroarylation of alkynes with an anti selectivity. Deuterium-labeling experiments, DFT calculation coupled with the use of a well-defined catalys...

Tandem CH activation/arylation between unactivated arenes and aryl halides catalyzed by iron complexes that bear redox-active non-innocent bisiminopyridine ligands is reported. Similar reactions catalyzed by first-row transition metals have been shown to involve substrate-based aryl radicals, whereas our catalytic system likely involves ligand-cen...

Almost a century has passed since valence bond (VB) theory was originally introduced to explain covalent bonding in the H2 molecule within a quantum mechanical framework. The past century has seen constant improvements in this theory, with no less than two distinct Nobel prizes based on work that is essentially developments in VB theory. Additional...

The reaction of a copper complex bearing iminosemiquinone ligands with a CF3(+) source provides an unprecedented Cu(II)-CF3 complex through ligand-based oxidation. Reactivity of this complex leads to nucleophilic trifluoromethylation of the ligand, suggesting an electronic interplay that results in a formal umpolung of the initial CF3(+).

The crystallization of a di-azido-α-cyclodextrin revealed a polymeric self-assembly involving a variety of azido-type interactions. The crystal arrangement relies on the cooperativity of a primary azido inclusion, a secondary azido–azido interaction involving an unprecedented distribution of canonical forms, and a tertiary azido–groove interaction....

The crystallization of a di-azido-α-cyclodextrin revealed a polymeric self-assembly involving a variety of azido-type interactions. The crystal arrangement relies on the cooperativity of a primary azido inclusion, a secondary azido–azido interaction involving an unprecedented distribution of canonical forms, and a tertiary azido–groove interaction....

The 5-diethoxyphosphonyl-5-methyl-1-pyrroline N-oxide superoxide spin adduct (DEPMPOOOH) is much more persistent (about 15 times) than the 5,5-dimethyl-1-pyrroline N-oxide superoxide spin adduct (DMPOOOH). The diethoxyphosphonyl group is bulkier than the methyl group and its electron-withdrawing effect is much stronger. These two factors could pl...

The reaction of a copper complex bearing iminosemiquinone ligands with a CF₃⁺ source provides an unprecedented Cu^II-CF₃ complex through ligand-based oxidation. Reactivity of this complex leads to nucleophilic trifluoromethylation of the ligand, suggesting an electronic interplay that results in a formal u...

Palladium catalyzed cross-coupling reactions are one of the most widely used class of transformation as shown by the Nobel prize awarded in 2010 to Heck, Negishi, and Suzuki. Computational chemistry has a long-standing partnership with organometallics catalysis, especially with palladium. But even in a largely explored field, novelties can emerge f...

Open-shell mechanisms are often at work in catalytic sequences involving first-row transition metals while usually not considered in palladium chemistry. Herein a computational study suggests their possible relevance in catalytic methods involving paramagnetic Pd(iii) intermediates. Indeed C-C bond forming reductive elimination previously thought t...

A simple hydrido-cobalt complex efficiently catalyses the highly regio- and stereoselective dimerisation of various terminal arylacetylenes under mild conditions. The corresponding (E)-1,4-enynes are obtained as sole isomers with good to excellent yields. DFT calculations revealed that the reaction proceeds via a CH activation/hydrocobaltation pat...

The conditions of formation of strong two-center one-electron bonds in neutral compounds are discussed. Both molecular orbital and valence bond analyses show that good candidates are adducts of radicals (.) AR3 (A=C, Si, Ge) of low ionization energy (IE) with boranes BX3 of high electron affinity (EA). This is confirmed by ab initio calculations. T...

The chemistry of bis(sulfoxides) is discussed from two starting materials, (Ss,Ss)-bis-p-tolylsulfinylmethane and (Ss,Ss)-bis-p-tolylsulfinyl alkylidenes. Reactions presented include Michael additions, ionic-radical crossover processes and coordination complexes formations.

In this article, we have studied the generation of a bissulfinylmethyl radical from the corresponding TEMPO and phenylselenyl bissulfoxide precursors. No univocal formation of the bissulfinylmethyl radical has been observed. Instead, complex mixtures have been obtained in thermal or photochemical conditions, showing prominent C-S homolytic bond cle...