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.

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.

Three-Component Synthesis of Substituted Perhydropyrans from β-Styrylmalonates, Aldehydes, and Alkoxyaluminum Dichlorides.

A three-component synthesis of substituted dimethyl dihydro-2-pyran-3,3(4)-dicarboxylates in up to 80% yields by the reaction of β-styrylmalonates with aromatic or aliphatic aldehydes in the presence of ROAlCl prepared in advance either by exposure of EtAlCl with air access or by mixing equimolar amounts of AlCl with a primary or secondary alcohol has been developed. If EtAlCl, itself, is used, dihydro-2-pyran-3,3(4)-diesters are not formed at all, while dimerization of styrylmalonates by (4 + 2)-annulation-type to give substituted tetrahydronaphthalenes is the main process. The possibility of using the CH-O-Al fragment of alkoxyaluminum dichlorides in cycloaddition reactions with α-CH-functionalization has been shown for the first time.

[Risk factors for venous thromboembolic complications in elderly and senile patients with diabetes mellitus planned for spinal surgery.].

The search for literature sources in domestic and foreign databases showed the absence of works devoted to the study of risk factors for venous thromboembolic events (VTE) in patients of the older age group with diabetes mellitus who are planned to undergo surgical interventions on the spine, which was the impetus for this study. The aim of the study was to study the risk factors for VTE in elderly and senile patients with diabetes mellitus who are scheduled for spinal surgery. A single-center retrospective study included 119 elderly and senile patients (64 men, 55 women, mean age 74,2±6,5 years) who underwent various surgical interventions on the spinal column.

Unveiling the contourite depositional system in the Vema Fracture Zone (Central Atlantic).

A combination of a high sediment input and intense bottom currents often leads to the formation of contourites (sediments deposited or significantly reworked by bottom currents). Both of these components are present in the Vema Fracture Zone valley which is the most important passageway for the distribution of the Antarctic Bottom Water from the West to the North-East of the Atlantic. However, no contourite drifts, moats or contourite channels have been found in this region in more than half a century of research.