Cu I -catalyzed cycloaddition (CA) of the ketonitrones, Ph 2 C=N + (R′)O – (R′ = Me, CH 2 Ph), to the disubstituted cyanamides, NCNR 2 (R = Me 2 , Et 2 , (CH 2 ) 4 , (CH 2 ) 5 , (CH 2 ) 4 O, C 9 H 10 , (CH 2 Ph) 2 , Ph(Me)), gives the corresponding 5-amino-substituted 2,3-dihydro-1,2,4-oxadiazoles (15 examples) in good to moderate yields. The reaction proceeds under mild conditions (CH 2 Cl 2 , RT or 45 °C) and requires 10 mol % of [Cu(NCMe) 4 ](BF 4 ) as the catalyst. The somewhat reduced yields are due to the individual properties of 2,3-dihydro-1,2,4-oxadiazoles, which easily undergo ring opening via N—O bond splitting. Results of density functional theory calculations reveal that the CA of ketonitrones to Cu I -bound cyanamides is a concerted process, and the copper-catalyzed reaction is controlled by the predominant contribution of the HOMO dipole –LUMO dipolarophile interaction (group I by Sustmann’s classification). The metal-involving process is much more asynchronous and profitable from both kinetic and thermodynamic viewpoints than the hypothetical metal-free reaction.

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The complexities of chemical composition and crystal structure are fundamental characteristics of minerals that have high relevance to the understanding of their stability, occurrence and evolution. This review summarises recent developments in the field of mineral complexity and outlines possible directions for its future elaboration. The database of structural and chemical complexity parameters of minerals is updated by H-correction of structures with unknown H positions and the inclusion of new data. The revised average complexity values (arithmetic means) for all minerals are 3.54(2) bits/atom and 345(10) bits/cell (based upon 4443 structure reports). The distributions of atomic information amounts, chemIG and strIG, versus the number of mineral species fit the normal modes, whereas the distributions of total complexities, chemIG,total and strIG,total, along with numbers of atoms per formula and per unit cell are log normal. The three most complex mineral species known today are ewingite, morrisonite and ilmajokite, all either discovered or structurally characterised within the last five years. The most important complexity-generating mechanisms in minerals are: (1) the presence of isolated large clusters; (2) the presence of large clusters linked together to form three-dimensional frameworks; (3) formation of complex three-dimensional modular frameworks; (4) formation of complex modular layers; (5) high hydration state in salts with complex heteropolyhedral units; and (6) formation of ordered superstructures of relatively simple structure types. The relations between symmetry and complexity are considered. The analysis of temporal dynamics of mineralogical discoveries since 1875 with the step of 25 years show the increasing chemical and structural complexities of human knowledge of the mineral kingdom in the history of mineralogy. In the Earth's history, both diversity and complexity of minerals experience dramatic increases associated with the formation of Earth's continental crust, initiation of plate tectonics and the Great Oxidation event.

A method of furo-annulation of 4-hydroxy-2oxoquinoline-3-carboxylates with 3-arylazirines under Cu(II) catalysis was developed to synthesize a variety of 2,3dihydrofuro[3,2-c]quinolones bearing a carbamate group at the C2 position. The reaction involves an azirine ring opening across the N−C2 bond and formation of a dihydrofuran ring with the inclusion of two azirine carbon atoms, accompanied by a shift of the ester group to the nitrogen. The discovered reaction is the first example of the use of 2H-azirines for furo-annulation.

Homoleptic copper(i) complexes featuring disubstituted cyanamides were obtained and characterized using experimental methods and their properties were studied theoretically.

This work is part of a project focused on the Somma–Vesuvius volcano and aimed at identifying Cu minerals related to mineralizing processes associated with magmatic activity in an active magmatic-hydrothermal system. A mineralogical survey was carried out on a set of samples represented by sublimates and fumarolic products from the collection of the Mineralogical Museum of the University of Naples Federico II (Italy). These samples are mainly related to most recent eruptive episodes of Vesuvius activity, from 1631 onward. Copper-bearing minerals were characterized, as well as associated minerals, by X-ray diffraction (XRD) scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). An investigation on the structural complexity of Cu-mineral assemblages with different temperature formations was also carried out using the TOPOS software package. The main copper phases are sulfates, followed by vanadates, hydroxyhalides, oxides, carbonates, silicates and finally, phosphates. New mineral occurrences for Vesuvius, both Cu-bearing and Cu-free, are described. Nevertheless, the fumarolic/alteration minerals at Vesuvius cannot be considered of economic relevance as a copper reservoir, this type of mineralizations are significant for copper crystal chemistry and for the knowledge of the mineralogical variants. The obtained datasets can be of interest for the knowledge of volcanic byproducts of copper ore deposits (i.e., porphyry copper systems) and of (base) metal segregation processes.