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Recently there has been an explosion of interest in the synthetic community for the addition of radicals into unsaturated organoboron-ate complexes. This review will give a concise outline for radical processes involving boron-ate complexes which trigger a subsequent anionotropic rearrangement.

Water or low molecular weight alcohols are, due to their availability, low price and low toxicity ideal reagents for organic synthesis. Recently, it was reported that, despite the very strong BDE of the O–H bond, they can be used as hydrogen atom donors in place of expensive and/or toxic group 14 metal hydrides when boron and titanium(III) Lewis acids are present. This finding represents a considerable innovation and uncovers a new perspective on the paradigm of hydrogen atom transfers to radicals. We discuss here the influence of complex formation and other association processes on the efficacy of the hydrogen transfer step. A delicate balance between activation by complex formation and deactivation by further hydrogen bonding is operative.

Radical reactions offer many advantages over conventional chemical reactions, lending themselves to numerous bond forming processes and rearrangements that are, clean, rapid, and tolerant of a wide range of functional groups. This review provides a brief overview of the design concepts behind new reactions illustrating, in particular, their relevance for the efficient synthesis of biomolecules. Two general reactions are highlighted: single electron transfer (SET) using SmI2 and hydrogen transfer using reagents such as those based on tin, thiols and phosphorous reagents. Intermolecular influences that may direct radical reactions, such as partial protonation and radical complexation, are also discussed.

The stereochemical outcome of intramolecular radical mediated hydrogen transfer (= radical translocation) is discussed. Low to excellent levels of stereocontrol are observed making such processes attractive for applications in target-oriented synthesis.

The radical reduction of B-alkylcatecholboranes into alkanes using alcohols and water as hydrogen atom source is described. This process involves a completely unexpected mechanism: the alcohol (or water) complexed to a borate derivative acts as a reducing agent. The complexation activates the alcohol resulting in a decrease of the O–H bond dissociation energy. This approach offers promising opportunities for the development of tin-free radical reducing agent. Closely related reports from the recent literature involving boron and titanium derivatives are also presented.

The intramolecular Schmidt reaction was first described at the beginning of the 1990s and rapidly proved to be a powerful tool for the fast assembly of complex nitrogen-containing heterocycles. This review focuses on the application of this reaction in the synthesis of natural products and other biologically relevant compounds.

Cylindricines, lepadiformine, and fasicularin are marine alkaloids with a common novel pyrrolo- and pyrido[1,2-j]quinoline skeleton. They have recently been isolated from various tunicates and have shown interesting cytotoxic effects which could be attributed to covalent interactions with DNA, as well as cardiovascular effects. The promising biological activities together with the unique structural features make these alkaloids interesting targets for natural product synthesis. This review focuses on the different approaches developed for their synthesis with a particular emphasis on the key step where the quaternary amino substituted carbon center is created.

Radical coupling of B-alkylcatecholboranes, in situ generated from the corresponding alkenes, with ethyl 2-(benzenesulfonylamino)acrylate is reported. This reaction represents an extension of the radical allylation of Balkylcatecholboranes by allylsulfones. This unique process allows the preparation of various ?-ketoesters (alkylated pyruvates) in a straightforward manner. It also demonstrates the generality of the radical mediated C–C bond formation starting from organoboranes and allylic benzenesulfonyl derivatives.

The radical carboazidation of alkenes could be achieved in water using triethylborane as initiator. This efficient process is complete in one hour at room temperature in an open system. These new tin-free azidation and carboazidation conditions are environmentally friendly and enable reactions to be run with an excess of either the alkene or the radical precursor. Furthermore, 3-pyridinesulfonyl azide could be used in order to avoid tedious purifications, especially when the reaction product has a similar chromatographic behavior to benzenesulfonyl azide, our original azidation reagent.

Four examples of the synthesis of simple natural products and analogues bearing several adjacent stereogenic centers are presented. In all these syntheses, a highly stereocontrolled radical process is used as a key step.

Radical reactions became during the last decade a very useful tool in organic synthesis. Spectacular progress has been made in the control of the stereoselectivity of these reactions. This contribution presents our recent results with 1- and 2-heteroatomsubstituted radicals in cyclic and acyclic systems. Several examples dealing with the use of Lewis acids to achieve high stereochemical control are presented.

Radical-mediated phenylselanyl-group transfer reactions have been used to introduce simultaneously substituents at the C(6)-endo- and C(5)-exo-positions of 7-oxabicyclo[2.2.1]hept-5-en-2-one derivatives. The key steps are a radical addition to a silyl ketene acetal and the cyclization of a 1-alkoxy-substituted ester radical.

Allylation rates of radicals with tributyl[2-(trimethylsilyl)prop-2-enyl]stannane (2) have been compared with the ones of the (prop-2-enyl)stannane (3) and [2-(methyl)-prop-2-enyl]stannane (4). The Me3Si substituent showed a rate-accelerating effect (4.2:1 to 6.5:1) relati ve to the H-atom and the Me group for nucleophilic radicals. With electrophilic radicals, the Me group has a better rate accelerating effect than the Me3Si group. All these results can be understood by postulating a partially polarized transition state. The 1-substituted vinylsilanes which are produced by radical allylation with 2 have been converted by protiodesilylation and ozonolysis to alkenes and ?-hydroxy ketones.

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Objective: To describe the epidemiological aspects of obesity in the workplace., Methodology: This was a descriptive and cross-sectional study conducted between February and November 2017 in an oil company. The data were collected from the activity reports of its occupational medicine department., Results: Of the 625 subjects in the study, there were 528 (85%) men and 97 (15%) women, for a sex ratio (M/F) of 5.4. The mean age was 38.8±9.3 years. The socio-economic level was very high and the "master's" degrees were the most represented (58.1%). The incidence of obesity was 21.1% (132 workers) with 72.7% of subjects in moderate obesity. There were 104 (78.8%) obese men and 28 (21.2%) obese women. The following were significantly associated with obesity: female sex (p=0.042), meal frequency (p=0.000), snacking (p=0.000), physical inactivity (p=0.000), place of work (p=0.00028) and work stress (p=0.000). Diabetes (p=0.00023) and hypertension (p=0.00117) were significantly associated with obesity. On the other hand, no significant association was found with meal location, addictions (alcohol and tobacco), work rhythm, sedentary work habits and hypercholesterolemia., Conclusion: Our study shows the extent of obesity, which is a real health problem, so far little known in the Congolese professional environment. This underlines the need to design a good obesity prevention strategy in this relatively young productive population., (Le comité de rédaction se réserve le droit de renvoyer aux auteurs avant toute soumission à l'avis des lecteurs les manuscrits qui ne seraient pas conformes à ces modalités de présentation. En outre il leur conseille de conserver un exemplaire du manuscrit, des figures et des tableaux.)