Experimental investigation of thermal annealing of nuclear-reactor-induced coloration in fused silica

Spectral transmission characteristics of fused silica over range of temperature prior to nuclear irradiation and during thermal annealing of reactor-induced coloratio

Optical absorption in transparent materials following high-temperature reactor irradiation

Reactor irradiation effects on optical absorption levels in fused silic

Optical absorption in fused silica during TRIGA reactor pulse irradiation

Spectral transmission characteristics of fused silica before, during, and after exposure to reactor irradiation pulse

A xanthate-transfer approach to a-trifluoromethylamines [2-(N-acetylamino)-4,4-Dimethoxy-1,1,1-trifluorobutane]

International audienc

Acyl Fluorides as Efficient Electrophiles for the Copper-Catalyzed Boroacylation of Allenes

The copper-catalyzed reaction of allenes with bis(pinacolato)diboron and acyl electrophiles is reported. In this transformation, acyl fluorides have been proven to be more efficient coupling partners than their chloride or carboxylate analogues. The optimized reaction conditions employed were shown to be compatible with a range of commonly used functional groups, thereby allowing the formation of a library of β-boryl β,γ-unsaturated ketones by varying the nature of the allene and acyl fluoride substrates

Steric, Electronic and Conformational Synergistic Effects in the Au(I)-catalyzed alpha-C-H Bond Functionalization of Tertiary Amines

Direct C-H bond functionalization is a useful strategy for the straightforward formation of C-C and C-Heteroatom bonds. In the present work, a unique approach for the challenging electrophilic Au-catalyzed alpha-C-H bond functionalization of tertiary amines is presented. Electronic, steric and conformational synergistic effects exerted by the use of a malonate unit in the substrate were key to the success of this transformation. This new reactivity was applied to the synthesis of tetrahydro-g-carboline products which, under oxidative conditions, could be converted into valuable structural motifs found in bioactive alkaloid natural product

N-cyclopropylimine-1-pyrroline rearrangement. A novel photochemical reaction

matrix presented A novel aza-(vinylcyclopropane-cyclopentene) photochemical rearrangement is reported. 1-Pyrrolines are easily synthesized in good yields from N-cyclopropylimines. Hydrogen, alkyl, and aryl groups can be placed anywhere within the system, and the reaction proceeds regiospecifically

Photochemistry of Imine-Group VI Carbene Complexes with Alkenes: Synthetic Scope and Photochemical Aspects

The irradiation of imine-group VI carbene complexes with alkenes leads to the formation of 1-pyrrolines through a mechanism involving an initial cyclopropanation followed by a light-induced [1,3]-sigmatropic rearrangement. The reaction has no limitations on the structural nature of the imine-carbene complexes and is general for terminal and acyclic or cyclic 1,2-disubstituted electron-poor olefins. From the studies on photochemical aspects such as excited-state quenching, quantum yield, excited-state sensitizers and Stern-Volmer plots, it is concluded that both excited states, singlet and triplet, undergo the photoreaction. As far as we know, this is the first photochemical study on these kinds of compounds