A well-defined homogeneous silver precatalyst can be utilized for the direct C-H functionalization of a wide range of aromatic nitrogen heterocycles with cyclopropanols under acid-free conditions. This reaction can be conducted on gram-scale and with low catalyst loadings (as low as 1%), which is rare for silver-catalyzed Minisci-type reactions. Moreover, reactivity trends, as well as steric and calculated electronic properties of the heterocycles, strongly suggest that silver-heterocycle complexes formed in situ behave as redox active catalysts and as Lewis acid activators of the heterocycle and that the electronic nature of the heterocyclic substrates tunes the reactivity of the resulting complexes.

Due to their high strain, unique bonding and relative ease of ring-cleavage, and because they are readily accessible, cyclopropanols have been employed in an increasing number of transition-metal-catalyzed CC and C-X (X = heteroatom) bond-forming reactions. We review the recent literature and organize all the methods developed along mechanistic lines. 1 Introduction and Scope 2 CC Bond Formation via Catalytic Generation and Coupling of Cyclopropanol-Derived Homoenolates 3 C-N Bond Formation via Catalytic Generation and Coupling of Cyclopropanol-Derived Homoenolates 4 CC Bond Formation via Stoichiometric Generation and Coupling of Cyclopropanol-Derived Homoenolates 5 Ring Expansion of Cyclopropanols to Cyclobutanones via Transition-Metal-Catalyzed Wagner-Meerwein Shift 6 Transition-Metal-Catalyzed Rearrangement of Cyclopropanols to Cyclopentenones and Cyclohexenones 7 Synthesis of Medium-Size Rings via Multicomponent Reactions Involving Cyclopropanols 8

Strained alcohols have featured prominently in a wide array of transition-metal-catalyzed cross-coupling reactions, but methods involving cyclopropanols have only been developed relatively recently. In this account, we describe our group's work in this area, and we provide a concise summary of other palladium-catalyzed methods for C-C bond-forming reactions using cyclopropanols. 1

Reactions of 2,2,3,3-tetracyanocyclopropanecarboxylic acid with potassium, sodium, calcium, strontium, barium, ammonium, N-methylpyridinium, N-methylquinolinium, N,N-dimethyl-1,4-diazabicyclo-[2.2.2]octane-1,4-diium, and N,N-dimethylanilinium iodides afforded the corresponding 3-cyano-4-dicyanomethylidene-5-oxo-4,5-dihydro-1H-pyrrol-2-olates. Scheme 1.

The particulars of radioactive contamination of concrete wastes by 137 Cs were studied. x-Ray phase analysis and chemical analysis show that clayey materials, including Al 2 O 3 , Fe 2 O 3 , K 2 O, and MgO, on which 137 Cs sorption is possible, were present in the concrete wastes. The content and form in which 137 Cs was found in radioactive concrete wastes from nuclear power facilities as well as in model samples were determined. When the wastes were treated with nitric acid the binder dissolved and a polydisperse suspension formed. The suspension consisted of three phases: solution, fine suspension, and rapidly settling precipitate of heavy filler particles. x-Ray phase analysis was performed and the 137 Cs mass ratio and distribution in the phases were determined. The possibility of decontaminating the concrete by a reagent method was evaluated.Large amounts of radwastes, a considerable fraction of which consist of concrete structures, are inevitably produced when nuclear power facilities are decommissioned. There are many known methods for decontaminating concrete. Usually, concrete structures are decontaminated by mechanical removal of the surface layer using different equipment, as a result of which secondary wastes in the form of fragmented concrete are formed [1]. Ordinarily, such wastes are conditioned by incorporation into cement prepared using liquid radwastes [2] or by saturation with a highly penetrating cement solution [3]. As a result, the volume of the cemented radwastes and correspondingly the storage costs increase.As a rule, concrete wastes are classified as medium-and low-level. 137 Cs is one of the main contaminating γ-and β-emitting radionuclides. Its half-life is about 30 years, so that cool-down of the wastes to lower the activity to a safe level is of little use and in many cases removing this isotope from concrete will make it possible to remove such wastes from the radwaste category.The objective of the present work is to assess the possibility of volume 137 Cs decontamination of fragmented concrete wastes. Concrete is a nonuniform composite material, so that to develop a method of decontamination it is necessary to study the form in which the radionuclides, specifically, 137 Cs, are found in the wastes.The objects of study were concrete wastes from the rehabilitation of radiologically hazardous facilities: sample 1 -a 25-kg concrete block with γ-ray dose rate 0.1 m away from the surface to 500 μSv/h and sample 2 -fragmented wastes with γ-ray dose rate 0.1 m from the surface not exceeding the background level. In addition, model samples obtained by contaminating clean concrete with a radioactive solution as well as by cementing a radioactive solution were studied.For γ-spectrometric analysis, the waste fragments were comminuted and average samples were taken. The samples were subjected to radiometric analysis performed using an ORTEC-GEM 35P (Finland) automated four-channel gamma spectrometer with a semiconductor detector in the central laboratory of the Moscow Scientific and Industria...