Comparative Evaluation of Mathematical Model and In Vivo Study of Calcium Phosphate Bone Grafts.

One of the key factors of the interaction 'osteoplastic material-organism' is the state of the implant surface. Taking into account the fact that the equilibrium in regeneration conditions is reached only after the reparative histogenesis process is completed, the implant surface is constantly modified. This work is devoted to the numerical description of the dynamic bilateral material-medium interaction under close to physiological conditions, as well as to the assessment of the comparability of the model with and experimental results.

FeCl-Mediated Rearrangement of Aminoperoxides into Functionalized Tetrahydrofurans: Dynamic Non-innocence of O-Ligands at an Fe Center Coordinates a Radical Cascade.

The selective reaction of cyclic aminoperoxides with FeCl proceeds through a sequence of O-O and C-C bond cleavages, followed by intramolecular cyclization, yielding functionalized tetrahydrofurans in 44-82% yields. Replacing the peroxyacetal group in the peroxide structure with a peroxyaminal fragment fundamentally alters the reaction pathway. Instead of producing linear functionalized ketones, this modification leads to the formation of hard-to-access substituted tetrahydrofurans.

The concept of Gallium-controlled double C-H functionalization of aliphatic CH-groups driven by Vinyl carbocations.

The direct C-H activation of inert C(sp)-H bonds in a hydrocarbon chain has been a very attractive target in organic synthesis for many decades. Among all the variety of processes, those driven by vinyl carbocations are quite scarce thus far, and it is hard to control for unstabilized vinyl cations. In this study, we designed a double C(sp)-H functionalization of unactivated alkyl CH groups to produce a totally substituted quaternary carbon stereocenter via insertion of vinyl carbocations.

The TaCl-Mediated Reaction of Dimethyl 2-Phenylcyclopropane-1,1-dicarboxylate with Aromatic Aldehydes as a Route to Substituted Tetrahydronaphthalenes.

It is found that the reaction of dimethyl 2-phenylcyclopropane-1,1-dicarboxylate with 2 equivalents each of aromatic aldehydes and TaCl in 1,2-dichloroethane at 23 °C for 24 h after hydrolysis gives substituted 4-phenyl-3,4-dihydronaphtalene-2,2(1)-dicarboxylates in good yield. This represents a new type of reactions between 2-arylcyclopropane-1,1-dicarboxylates and aromatic aldehydes, yielding chlorinated tetrahydronaphthalenes with a arrangement of the aryl and chlorine substituents in the cyclohexene moiety. A plausible reaction mechanism is proposed.

Formal High-Order Cycloadditions of Donor-Acceptor Cyclopropanes with Cycloheptatrienes.

The design of various cycloaddition/annulation processes is one of the most intriguing challenges in the development of donor-acceptor (D-A) cyclopropane chemistry. In this work, a new class of formal high-order [6+n]-cycloaddition and annulation processes of D-A cyclopropanes with cycloheptatriene systems has been designed and reported, to fill a significant gap in the chemistry of D-A cyclopropanes. The reactivity of methylated cycloheptatrienes from Me1 to Me5 as well as unsubstituted cycloheptatriene was studied in detail under GaCl activation conditions, which makes it possible to efficiently generate gallium 1,2-zwitterionic complexes or 1,3-zwitterionic intermediates starting from D-A cyclopropanes, while other Lewis acids are ineffective and non-selective.