H/D Exchange Using Hot Heavy Water.

Metal-catalyzed H/D exchange in hydrothermal deuterium oxide, performed in an autoclave using external heating or in a sealed glass tube under microwave irradiation, was shown to be an efficient method for preparing various deuterium-labeled compounds. Phosphonium salts for the Wittig reaction were deuterated at the α-position in the presence of MS 4A under microwave irradiation; primary alcohols and primary/secondary amines were deuterated at the α-position in the presence of ruthenium catalyst under microwave irradiation; metal-catalyzed direct C-H functionalizations on sp³ and sp² carbon gave the corresponding fully deuterated products under hydrothermal conditions. These methods gave various deuterium-labelled compounds efficiently using D₂O as a D-atom source.

Giant Faraday Rotation through Ultrasmall Fe Clusters in Superparamagnetic FeO-SiO Vitreous Films.

Magnetooptical (MO) glasses and, in particular, Faraday rotators are becoming key components in lasers and optical information processing, light switching, coding, filtering, and sensing. The common design of such Faraday rotator materials follows a simple path: high Faraday rotation is achieved by maximizing the concentration of paramagnetic ion species in a given matrix material. However, this approach has reached its limits in terms of MO performance; hence, glass-based materials can presently not be used efficiently in thin film MO applications.

1-Silyl-1-boryl-2-alkenes: Reagents for Stereodivergent Allylation Leading to 4-Oxy-(E)-1-alkenylboronates and 4-Oxy-(Z)-1-alkenylsilanes.

Silylboryl reagents for organic synthesis: 1-silyl-1-boryl-2-alkenes (2) were prepared efficiently by gem-silylborylation of α-chloroallyllithium compounds from (dimethylphenylsilyl)(pinacolato)borane (1; see scheme, LDA=lithium diisopropylamide) and were demonstrated to allylate acetals and aldehydes in the presence of a Lewis acid to produce (E)-4-alkoxy-alkenylboronates. Heating the reagents with aldehydes in the absence of Lewis acid afforded (Z)-4-hydroxy-alkenylsilanes stereospecifically.

Alkylative Preparation of α-Silylalkylmagnesium from R SiCHBr Using a Magnesate Reagent.

Magnesium-bromine exchange to provide the 1-bromo-1-silylmethylmagnesium species is mediated by treatment of dibromomethylsilane with an trialkylmagnesate reagent. The addition of a copper catalyst induces facile migration of an alkyl group to afford an α-silylalkylmagnesium compound, which furnishes α-silyl ketones in good yield upon treatment with acyl chloride.