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2D-activation strain diagrams of the possible cyanide additions to (S)-2-phenylpropanal leading to the corresponding syn (left) and anti (right) reaction products. Strain energy (top) and interaction energy (bottom). All data were computed at the ZORA-M06-2X/TZ2P//M06-2X-6-311+G(d) level
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Quantum chemical calculations were carried out to quantitatively understand the origin of the Felkin–Anh(–Eisenstein) model, widely used to rationalize the π-facial stereoselectivity in the nucleophilic addition reaction to carbonyl groups directly attached to a stereogenic center. To this end, the possible approaches of cyanide to both (S)-2-pheny...
Citations
This perspective begins with the discovery of the Grignard reaction by a graduate student in the last years of the 19th century, followed by describing why it has remained largely unexplained for more than a century. From the summary of what has been achieved, focusing on the computational aspects, it is now clear that further studies of the chemistry of any chemical species that is highly sensitive to solvents, such as Group I and II elements, require a holistic approach that includes the solute and the solvent together. Ab initio molecular dynamics, which meets these requirements, has produced some results but has hit hard limits due to its relatively high computational costs. In these days, it is becoming clear that data-driven methods, including machine learning potentials and simulations driven by quantitative on-the-fly calculation of relevant observables, have the potential to better and more completely explore the very large chemical space associated with the presence of a large number of species in solution. These methodologies have the chance to give the keys to enter the challenging and still poorly explored world of chemical species whose behaviour and reactivity are strongly influenced by the solvent and the experimental conditions.
The impact of the nature of the Group 15 element on both the bonding situation and the reactivity of gold(I)-C ≡ E (E = N to Bi) complexes has been studied quantum chemically within the density theory functional framework. For this purpose, the 1,3-dipolar cycloaddition reaction involving tBuN3 as dipole has been selected and its main features, including the regioselectivity of the transformation and the in-plane aromaticity of the corresponding transition structures, have been investigated. It is found that the reactivity of the complexes is increased as one moves down Group 15 (N ≪ P < As < Sb < Bi). This reactivity trend has been rationalized by using the combined activation strain model and energy decomposition analysis methods, which indicate that the process is mainly dominated by the strain energy required by the reactants to reach the corresponding transition state geometries.
The poorly understood factors controlling the reactivity and selectivity (both stereo‐ and enantioselectivity) of catalyzed Diels‐Alder reactions involving cyclobutenones as dienophiles have been analyzed in detail by means of Density Functional Theory calculations. To this end, the reactions with cyclopentadiene and furan as dienes and 3‐(methoxycarbonyl)cyclobutenone catalyzed by Corey's chiral oxazaborolidium ion (COBI) have been selected and compared to their analogous uncatalyzed transformations. The combined Activation Strain Model of reactivity and Energy Decomposition Analysis methods have been used to quantitatively understand the acceleration and selectivity induced by the catalyst in this reaction.