Bending the planar trigonal boron center of triphenylborane by connecting its aryl rings with carbon or phosphorus linkers gave access to a series 9-boratriptycene derivatives unprecedented structures and reactivities. NMR spectroscopy X-ray diffraction Lewis adducts these non-planar acids weak base revealed particularly strong covalent bond formation. The first adduct trivalent compounds Tf2 N- anion illustrates unrivaled acidity species. Increasing pyramidalization using cationic...

The [4+2] Diels-Alder cycloaddition reaction between 2,5-DMF (1) and ethylene derivatives (2a-h) activated by electron-withdrawing groups has been studied at the density functional theory levels using a panoply of tools to unravel mechanisms. From analysis reactivity indices, 2a-h behave as electrophiles while 1 nucleophile, activation double bond increases its electrophilicity, which is accompanied an enhancement polarity reaction. Gibbs free energy decreases linearly function this increase...

The Cover Feature shows how density functional theory was employed to unravel the bond-breaking and -forming steps along reaction coordinate of Diels–Alder reactions between 2,5-DMF ethylene derivatives activated by electron-withdrawing substituents, thus demonstrating evolution distribution electron into basins unveils mechanism. More information can be found in Research Article B. Champagne co-workers (DOI: 10.1002/cphc.202400896).

Understanding the molecular mechanism of 1,3-dipolar cycloadditions using bonding evolution theory.

Abstract Bending the planar trigonal boron center of triphenylborane by connecting its aryl rings with carbon or phosphorus linkers gave access to a series 9‐boratriptycene derivatives unprecedented structures and reactivities. NMR spectroscopy X‐ray diffraction Lewis adducts these non‐planar acids weak base revealed particularly strong covalent bond formation. The first adduct trivalent compounds Tf 2 N − anion illustrates unrivaled acidity species. Increasing pyramidalization using...

Abstract The [3 + 2] cycloaddition (32CA) reactions of three nitrile oxides (NOs) (R‐CNO; R = Ph, CO 2 Me, and Br) with methyl acrylate (MA) have been theoretically studied within the molecular electron density theory. Topological analysis localization function these NOs permits to establish that they will participate in zw‐type 32CA reactions. Analysis conceptual DFT indices indicates a low polar character as consequence relatively electrophilic MA nucleophilic NOs, agreement global...

The reaction mechanism of the [3 + 2] intramolecular cycloaddition 3,3-dimethyl-2-(prop-2-en-1-yloxy) and (prop-2-en-1-ylsulfanyl) nitrile oxides is analyzed using different DFT functionals with 6-311++G(d,p) basis set. activation energies for cis trans pathways are evaluated at DFT, MP2, CCSD(T) levels theory as well their Gibbs free energy counterparts. It shown that regioisomers both thermodynamic kinetic compounds, in agreement experimental outcomes. For a deeper understanding mechanism,...

Bis-N-heterocyclic carbene ligands (bis(NHC)) have introduced a new approach to designing homogeneous and heterogeneous catalysts, demonstrating the versatility of ligand concepts in catalysis.

A Molecular Electron Density Theory study of the zw-type 32CA reactions acetonitrile oxide (NO) with two 7-oxanorborn-5-en-2-ones (ONBs) has been performed at DFT B3LYP/6-31G(d) computational level. These cycloadditions proceed through one-step mechanisms high activation energies and present low para regio complete syn diastereofacial selectivities. While non-polar character these reactions, which is consequence insufficient electrophilic ONBs, according to analysis conceptual reactivity...

Abstract In the present work, electron density flows involved throughout progress of four reaction pathways associated with intramolecular [3 + 2] cycloaddition cyclic nitrones Z‐1 and E‐1 are analyzed using bonding evolution theory. The study highlights nonconcerted nature processes, which can be described as taking place in several stages. first stage consists depopulation initial CN CC double bonds to render N lone pair corresponding CN CC single bonds, these electronic initiate...

Abstract The intramolecular [3+2] cycloaddition (IM32CA) reactions of cyclic nitrones Z ‐ 7 and E have been studied within the Molecular Electron Density Theory at MPWB1K/6‐311G(d) computational level. For these IM32CA reactions, which take place through a one–step mechanism, two regioisomeric reaction paths associated with formation 6,6,5‐ring fused 6,5,5‐ring bridged isoxazolidines considered. Analysis relative Gibbs free energies indicates that under thermodynamic control, are completely...

Abstract The nitration reaction of nitrobenzene with nitronium ion yielding ortho ‐, meta ‐ and para ‐dinitrobenzenes has been studied within the Molecular Electron Density Theory, using DFT computational methods at B3LYP/6‐311G(d,p) level. This electrophilic aromatic substitution (EAS) takes place through a two‐step mechanism involving formation tetrahedric cation intermediate. attack on is rate‐determining step this EAS reaction, consequently, responsible for composition mixture....

The reaction mechanisms of the decomposition glycerol carbonate have been investigated at density functional theory level within bond evolution theory. four pathways yield to 3-hydroxypropanal (TS1), glycidol (TS2a and TS2b), 4-methylene-1,3-dioxolan-2-one (TS3). study reveals non-concerted processes with same number (four) structural stability domains for each pathway. For two decarboxylation mechanisms, first steps are similar. They correspond cleavage single CO bonds detriment increased...

Density functional theory with the ωB97X-D exchange-correlation together implicit as well explicit solvation is used to describe reactions of adenine and guanine purine bases on N,N',N″-triethylenethiophosphoramide (thioTEPA), an alkylating agent anticancer drug. This reaction decomposed into (i) a nucleophilic addition (ii) proton "migration" that mediated by solvent molecules. The calculations reveal first step rate determining presence water molecule mediate migration has negligible role...

The molecular mechanism of the reactions between four carbonyl oxides and ammonia/water are investigated using M06-2X functional together with 6-311++G(d,p) basis set. analysis activation reaction enthalpy shows that exothermicity each process increased substitution electron donating substituents (methyl ethenyl). Along pathway, two new chemical bonds C-N/C-O O-H expected to form. A detailed flow density during their formation have been characterized from perspective bonding evolution theory...

This study is focused on describing the molecular mechanism beyond picture provided by evolution of orbitals, valence bond structures along reaction progress, or conceptual density functional theory. Using bonding theory (BET) analysis, we have deciphered 1,3-dipolar rearrangement between acetonitrile oxide and (1S,2R,4S)-2-cyano-7-oxabicyclo[2.2.1]hept-5-en-2-yl acetate derivatives. The BET revealed that formation C-C takes place via a usual sharing model before O-C one also formed in...

Abstract We investigated the flow of electron density along cyclocondensation reaction between ethyl acetate 2‐oxo‐2‐(4‐oxo‐4 H ‐pyrido[1.2‐a]pyrimidin‐3‐yl) polyazaheterocycle ( 1 ) and ethylenediamine 2 at ωB97XD/6–311++G(d,p)computational method within bond evolution theory (BET). The exploration potential energy surface shows that this has three channels (1–3) with formation product 3 via channel‐2 (the most favorable one) as main is in good agreement experimental observations. BET...

The molecular mechanisms of three intramolecular rearrangements (I, the rearrangement allyloxycycloheptatriene to yield tricyclic ketones; II, cycloaddition a nitrone-alkene render two isoxazolidines; and III, decomposition N-carbamoyl-L-proline in tetrahydro-1H-pyrrolo[1,2-c]imidazole-1,3(2H)-dione plus water, or tetrahydro-1H,3H-pyrrolo[1,2-c]oxazole-1,3-dione ammonia) have been studied by means bonding evolution theory (BET). thermal I is composed sigmatropic coupled an Diels–Alder...

Evolution of some key ELF basins along the IRC most favorable ortho / endo reaction path.

We have investigated the reaction mechanisms of [3+2] cycloaddition (32CA) between N -methylphenylnitrone and styrene catalyzed by chromium tricarbonyl complex at MPWB1K/6-311G(d,p) level approximation.

The reaction mechanisms of [3 + 2] cycloaddition (32CA) between two N-substituted phenylnitrones (NPPN and NtBPN) styrene (STY) in the presence a chromium tricarbonyl complex (Cr(CO)3) have been studied within framework molecular electron density theory at MPWB1K/6-311G(d,p) level. Activation energy analysis reveals that these 32CA reactions take place with high activation barriers due to their non-polar character exo/ortho approach as favorable path. TS1 series (NPPN) is about 5–6 kcal/mol...