Risultati preliminari delle indagini archeologiche ed etnografiche presso il sito di Togolok 1

Modern Turkmenistan is mainly constituted by a desert landscape, yet despite its harsh climate, cultures have been able to construct networks of water channels since the Bronze Age. This has resulted in a man-made landscape that integrates towns and villages. Extensive surveys and recent archaeological excavations have highlighted that between 2400 and 2100 BC (Namazga V period), the region of the Murghab alluvial fan was characterised by the development of complex urban societies. However, starting from the Late Bronze Age, a new group of mobile pastoralists appeared in the Murghab region and settled along the edges of the sedentary sites. Although their presence is well-attested both by survey and excavation data, their degree of interaction with the sedentary farmers is still debated. In modern Turkmenistan, semi-mobile shepherds continue to drive their cattle across the Murghab, using mobile camps for different months. This paper presents the preliminary results of the excavation of the sedentary site of Togolok 1, as well as the first ethnographic study of the mobile communities of the Murghab region

Discovery and development of organic super-electron-donors

Based on simple ideas of electron-rich alkenes, exemplified by tetrakis(dimethylamino)ethene, TDAE, and on additional driving force associated with aromatization, families of very powerful neutral organic super-electron-donors (SEDs) have been developed. In the ground state, they carry out metal-free reductions of a range of functional groups. Iodoarenes are reduced either to aryl radicals or, with stronger donors, to aryl anions. Reduction to aryl radicals allows the initiation of very efficient transition-metal-free coupling of haloarenes to arenes. The donors also reduce alkyl halides, arenesulfonamides, triflates, and triflamdes, Weinreb amides, and acyloin derivatives. Under photoactivation at 365 nm, they are even more powerful and reductively cleave aryl chlorides. They reduce unactivated benzenes to the corresponding radical anions and display original selectivities in preferentially reducing benzenes over malonates or cyanoacetates. Additionally, they reductively cleave ArC−X, ArX−C (X = N or O) and ArC−C bonds, provided that the two resulting fragments are somewhat stabilized

Identifying the roles of amino acids, alcohols and 1,2-diamines as mediators in coupling of haloarenes to arenes

Coupling of haloarenes to arenes has been facilitated by a diverse range of organic additives in the presence of KO(t)Bu or NaO(t)Bu since the first report in 2008. Very recently, we showed that the reactivity of some of these additives (e.g., compounds 6 and 7) could be explained by the formation of organic electron donors in situ, but the role of other additives was not addressed. The simplest of these, alcohols, including 1,2-diols, 1,2-diamines, and amino acids are the most intriguing, and we now report experiments that support their roles as precursors of organic electron donors, underlining the importance of this mode of initiation in these coupling reactions