A direct iron­(III)-catalyzed Prins–Peterson reaction involving α-substituted γ-triphenylsilyl bis-homoallylic alcohols and aldehydes is described. Thus, cis-Δ4-2,7-disubstituted oxepenes were synthesized in a diastereoselective reaction using sustainable catalytic conditions (3–5 mol %). This highly productive process is the result of a cascade of three chemical events with the concomitant formation of a C–O bond, a C–C bond, and a Δ4 endocyclic double bond, through a Prins cyclization followed by a Peterson-type elimination. This tandem reaction is chemoselective vs the classical Prins cyclization.

This minireview focuses on recent advances in the synthesis of seven-membered ring oxacycles, whether saturated, unsaturated, fused or isolated. We cover a remarkable variety of strategies and methods developed during the past two decades, based mainly on cyclizations, ring-closing metathesis, conjugate additions, and ring expansions. The cyclizations can be generated directly or triggered through an oxocarbenium ion, carbocation or iminium-type species. Also discussed [a] Prof.

A new method that allows the complete control of the regioselectivity of the hydrobromination reaction of alkenes is described. Herein, we report a radical procedure with TMSBr and oxygen as common reagents, where the formation of the anti -Markovnikov product occurs in the presence of parts per million amounts of the Cu(I) species and the formation of the Markovnikov product occurs in the presence of 30 mol % iron(II) bromide. Density functional theory calculations combined with Fukui’s radical susceptibilities support the obtained results.

A highly efficient, diastereoselective, iron(III)-catalyzed intramolecular hydroamination/cyclization reaction involving α-substituted amino alkenes is described. Thus, enantiopure trans-2,5-disubstituted pyrrolidines and trans-5-substituted proline derivatives were synthesized by means of a combination of enantiopure starting materials, easily available from l-α-amino acids, with sustainable metal catalysts such as iron(III) salts. The scope of this methodology is highlighted in an enantiodivergent approach to the synthesis of both (+)- and (-)-pyrrolidine 197B alkaloids from l-glutamic acid. In addition, a computational study was carried out to gain insight into the complete diastereoselectivity of the transformation.

A new, direct, and diastereoselective synthesis of activated 2,3,4,6-tetrasubstituted tetrahydro-2H-pyrans is described. In this reaction, iron(III) catalyzed an S2'-Prins cyclization tandem process leading to the creation of three new stereocenters in one single step. These activated tetrahydro-2H-pyran units are easily derivatizable through CuAAC conjugations in order to generate multifunctionalized complex molecules. DFT calculations support the in situ S2' reaction as a preliminary step in the Prins cyclization.

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Systems biology models are typically considered across a spectrum from mechanistic to abstracted description; however, the lines between these forms of modeling are increasingly blurred. Ever-increasing computational power is providing novel opportunities for bridging time and length scales. Furthermore, despite biological mechanisms or network topology often ill-defined, the acquisition of high-throughput data leaves modelers with the desire to leverage available measurements. This review surveys modeling tools in which two or more mathematical forms are blended to describe time-dependent processes in a multivariate system. While most commonly manifested as continuous/discrete description, other forms such as mechanistic/inference or deterministic/stochastic hybrid models can be generated. Recent innovations in hybrid modeling methodologies and new applications illustrate advantages for combining model formats to gaining biological systems level insight.

The physical factors governing the catalysis in Lewis acid-promoted carbonyl-ene reactions have been explored in detail quantum chemically. It is found that the binding of a Lewis acid to the carbonyl group directly involved in the transformation greatly accelerates the reaction by decreasing the corresponding activation barrier up to 25 kcal/mol. The Lewis acid makes the process much more asynchronous and the corresponding transition state less in-plane aromatic. The remarkable acceleration induced by the catalyst is ascribed, by means of the activation strain model and the energy decomposition analysis methods, mainly to a significant reduction of the Pauli repulsion between the key occupied π-molecular orbitals of the reactants and not to the widely accepted stabilization of the LUMO of the enophile.