Palladium-catalyzed C-C cross-coupling reactions (Suzuki-Miyaura, Negishi, Stille, Sonogashira, etc.) are among the most useful in modern organic synthesis because of their wide scope and selectivity under mild conditions. The many steps involved availability competing pathways with similar energy barriers cause mechanism to be quite complicated. In addition, short-lived intermediates difficult detect, making it challenging fully characterize these using purely experimental techniques....

Gold(I) complexes featuring electron acceptor ligands such as phosphites and phosphoramidites catalyze the [4C+2C] intramolecular cycloaddition of allenedienes. The reaction is chemo- stereoselective, provides trans-fused bicyclic cycloadducts in good yields. Moreover, using novel chiral phosphoramidite-based gold catalysts it possible to perform with excellent enantioselectivity. Experimental theoretical data dismiss a cationic mechanism involving intermediate II suggest that formation...

The reaction mechanism of the gold(I)-phosphine-catalyzed hydroamination 1,3-dienes was analyzed by means density functional methods combined with polarizable continuum models. Several mechanistic pathways for were considered and evaluated. It found that most favorable series steps include ligand substitution in catalytically active Ph3PAuOTf species between triflate substrate, subsequent nucleophile attack N-nucleophile (benzyl carbamate) on activated double bond, which is followed proton...

The reaction between acetylenes and sulfoxides, studied as a test case for gold-catalyzed intermolecular addition, provides the oxyarylation compounds 3 in good yields. Unpredictably, all cases single regioisomer arising from electrophilic aromatic alkylation at position adjacent to sulfur atom is obtained instead of expected Friedel-Crafts regioisomer. A new concerted mechanism based on DFT calculations proposed account products this gold(I)-catalyzed reaction.

Efficient at room temperature: The Au complex generated in situ from [(IPr)AuCl] and AgSbF(6) promotes the [4C+3C] intramolecular cycloaddition of allenes dienes temperature, a particularly efficient versatile manner. A DFT study on dimethylallenyl precursors agreed with formation metal-allyl cation intermediate, points to 1,2-hydride shift as key rate-limiting step.

The use of the hypervalent iodine reagents in oxidative processes has become a staple modern organic synthesis. Frequently, reactivity λ3 iodanes is further enhanced by acids (Lewis or Brønsted). origin such activation, however, remained elusive. Here, we common combination PhI(OAc)2 with BF3·Et2O as model to fully explore this activation phenomenon. In addition spectroscopic assessment dynamic acid–base interaction, for first time putative PIDA·BF3 complex been isolated and its structure...

Abstract An artificial heme enzyme was created through self‐assembly from hemin and the lactococcal multidrug resistance regulator (LmrR). The crystal structure shows bound inside hydrophobic pore of protein, where it appears inaccessible for substrates. However, good catalytic activity moderate enantioselectivity observed in an abiological cyclopropanation reaction. We propose that dynamic nature LmrR protein is key to activity. This supported by molecular dynamics simulations, which showed...

The result of the application different approaches based on ideal gas/rigid rotor/harmonic oscillator (IGRRHO) model, commonly used in popular software packages, for calculation free energies solution is compared with that ab initio molecular dynamics a process involving ligand exchange palladium complexes. IGRRHO-based considered differ most cases extent to which rotational and translational contributions are included correction. Our study supports use energy values directly obtained from...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnalysis of solvent effects on the Menshutkin reactionMiquel Sola, Agusti Lledos, Miquel Duran, Juan Bertran, and Jose Luis M. AbboudCite this: J. Am. Chem. Soc. 1991, 113, 8, 2873–2879Publication Date (Print):April 1, 1991Publication History Published online1 May 2002Published inissue 1 April 1991https://pubs.acs.org/doi/10.1021/ja00008a013https://doi.org/10.1021/ja00008a013research-articleACS PublicationsRequest reuse permissionsArticle...

The Shvo catalyst is one of the most prominent examples a hydrogen-transfer successfully applied in broad scope processes. reaction takes place by transferring hydride (bonded to metal center) and proton ligand) double bond. mechanism for process, however, matter controversy. Experimental studies means primary deuterium isotope effects on hydrogenation ketones via active reducing form Casey Bäckvall groups concluded that carbonyl concerted. Nevertheless, it not clear whether goes through an...

In this review, transformations of C–F to C–X bonds mediated by transition-metal complexes are considered from the ligand's perspective. bond activation reactions, ligands (L) bonded can act as spectators but also assist reaction. The latter case is important in heterolytic cleavage nucleophilic addition reactions. When L an electrophile (E), assistance ligand facilitates fluoride departure when metal attacks at C. contrast, a nucleophile (X), responsible for and reaction leads new bond,...

The reaction mechanism for the Pd-catalyzed Cu-free Sonogashira is analyzed by means of density functional theory (DFT) calculations on a model system. most common routes proposed in literature this reaction, namely, carbopalladation and deprotonation, are considered. In agreement with experiment, clearly demonstrate that route can be discarded. For case deprotonation route, however, pathway may take place via several alternatives; suggest all them feasible. Moreover, an additional where...

The dehydrogenation of n-hexane and cycloalkanes giving n-hexene cycloalkenes has been observed in the reaction such hydrocarbons with hydrogen peroxide, presence copper complexes bearing trispyrazolylborate ligands. This catalytic transformation provides typical oxidation products (alcohol ketones) small amounts alkenes, a novel feature this kind oxidative processes. Experimental data exclude participation hydroxyl radicals derived from Fenton-like mechanisms. DFT studies support copper-oxo...

Abstract Recent experimental reports have called into question the validity of boronate mechanism (through a RB(OH) 3 − intermediate) for transmetalation step in Suzuki–Miyaura cross‐coupling, favoring instead palladium hydroxo pathway an [L n Pd(R′)(OH)] intermediate). Herein we report DFT calculations with M06 functional performed on realistic model systems, including combination explicit solvent molecules along continuum method. These computational results support mechanism. The...

An artificial imine reductase results upon incorporation of a biotinylated Cp*Ir moiety (Cp* = C5Me5–) within homotetrameric streptavidin (Sav) (referred to as Cp*Ir(Biot-p-L)Cl] ⊂ Sav). Mutation S112 reveals marked effect the Ir/streptavidin ratio on both saturation kinetics well enantioselectivity for production salsolidine. For [Cp*Ir(Biot-p-L)Cl] S112A Sav, reaction rate and selectivity (up 96% ee (R)-salsolidine, kcat 14–4 min–1 vs [Ir], KM 65–370 mM) decrease fully saturating all...

Starting from biochemical knowledge followed by computational design, an artificial metallo-hydratase comprising unnatural metal binding amino acid was created.

Computational chemistry is a valuable aid to complement experimental studies of organometallic systems and their reactivity. It allows probing mechanistic hypotheses investigating molecular structures, shedding light on the behavior properties assemblies at atomic scale. When approaching chemical problem, computational chemist has decide theoretical approach needed describe electron/nuclear interactions composition model used approximate actual system. Both factors determine reliability...

In this article, we present a new approach to expand the range of application protein-ligand docking methods in prediction interaction coordination complexes (i.e., metallodrugs, natural and artificial cofactors, etc.) with proteins. To do so, assume that, from pure computational point view, hydrogen bond functions could be an adequate model for bonds as both share directionality polarity aspects. model, metalloligands can performed without using any geometrical constraints or energy...