Schlenk technique

Not only the preparation of so far unknown compounds, but also the development of new synthesis techniques such as the Schlenk technique and vacuum-line technique which allow the handling and manipulation of air- and moisture-sensitive, pyrophoric compounds, are the most striking breakthroughs of their fascinating work. 

All reactions and manipulations were carried out under an inert atmosphere (N2 or Ar gas) using the Schlenk technique. Solvents were freshly distilled under an Ar atmosphere using the standard procedures (Na/BC/benzophenone or CaH2). Chromatography was performed on alumina (aluminum oxide, activity Il-IV(Merck art 1097). The H- and C-NMR spectra were recorded on a Bruker AC-200 spectrometer ( H, 200 MHz) and Nippon... 

Reagents and diy solvents were purchased from Aldrich or VWR and used without further treatment. Synthetic preparation of the complexes was done using standard Schlenk techniques (diy aigon) unless otherwise stated. Standard rathenium(ll) precursors were prepared as described in the literature or via internal routes. 

Reactions were conducted under N2 using glovebox and Schlenk techniques conditions and analytical methods are described in Tables and text. See also ref. 1 for details of how hydration yields were determined by NMR. 

All operations were carried out under inert atmosphere (argon) using standard Schlenk techniques. Prior to use, solvents were freshly distilled from sodium tetraethylaluminate under argon. Deuterated solvents were treated with sodium or sodium tetraethylaluminate, distilled, and stored under argon. 

Some of the procedures described in the following chapters had to be carried out under an inert atmosphere, nitrogen or argon, to minimize contact with oxygen and moisture. It is then necessary to use Schlenk techniques including the utilization of a vacuum line connected to a high vacuum pump and an inert gas inlet. The use of such equipment requires experience in working under anhydrous conditions. 

The following operations are all carried out under oxygen-free nitrogen using standard Schlenk techniques.9,10 Solvents and liquid reagents are degassed before use. 

The present method is the only documented synthesis of trimethylamine-isocyanoborane adduct, the first boryl isocyanide reported. The procedure may be general and thus useful for the preparation of other amine-isocyano and amine-pseudohaloborane adducts. Readily available materials are used, and a high yield of crude or purified product is obtained in an estimated 10-hour working period. Schlenk techniques are advocated for this work, but if Schlenk-ware is not available solutions may be transferred quickly in air and subsequently handled under a nitrogen atmosphere. 

All solvents were freshly distilled under dinitrogen from an appropriate drying agent immediately prior to use. Glassware was either kept in an oven at 150°C overnight or flame-dried under vacuum. All manipulations were carried out under dinitrogen using standard Schlenk techniques. 

Caution. Phosgene is a highly toxic gas that reacts with water to form HCl and has a characteristic odor of freshly mown hay. It is necessary to carry out this portion of the reaction using standard Schlenk techniques and in a well-ventilated fume hood. Unreacted phosgene can be neutralized with aqueous base. 

All of the following manipulations are performed under argon using standard Schlenk techniques. Solvents are degassed and distilled under nitrogen immediately before use unless otherwise noted. (Cp RuCl2)2 is available from Strem Chemicals, Inc., and is used as received. Lithium borohydride, LiBEU (2.0 M in tetrahydrofuran), and borane tetrahydrofuran, BH3 THF (1.0 M in tetrahydro-furan), are available from Aldrich Chemical Co. and are used as received. Note that these solutions decrease in molarity depending on time and use, and, if solutions are not titrated before use, appropriate increases in the volumes of solution used may be required. 

All reactions are carried out under N2 atmosphere with use of standard Schlenk techniques. Solvents are dried appropriately before use. Ceo (99.5%, Southern Chemical Group, LLC) is used without further purification. Anhydrous trimethylamine A-oxide (mp 225-230°C) was obtained from Me3N0-2H20 (98%, Aldrich) by sublimation (3 times) at 90-100°C under vacuum. 

Note All operations must be carried out in oven-dried glassware using Schlenk techniques under an atmosphere of argon and conducted in an efficient fume cupboard. 

The reaction was carried out under an argon atmosphere using standard Schlenk techniques. To a suspension of NaH (21.Og, 0.52 mol) in THF (1 L), (R)-BINOL (50.0 g, 0.175 mol) was added. The mixture was stirred for 45 min, cooled down to 0°C and MOMCl (36.5 mL, 0.44 mol) was injected. The solution was allowed to warm to room temperature, treated with saturated sodium carbonate solution (300 mL) and water (100 mL). The mixture was separated and the aqueous phase extracted with diethyl ether (4 X 100 mL). The combined organic fractions were dried (sodium sulfate) and concentrated under reduced pressure to afford the crude product, which was purified by column chromatography (500 g silica gel, eluent w-hexane/ CH2CI2 1 1 CH2C12) to yield the protected BINOL as a colourless solid (53.0 g, 96%). 

All manipulations must be carried out in an inert atmosphere using standard Schlenk techniques and solvents that have been freshly distilled under nitrogen or argon. Methyllithium ( 5% solution in diethyl ether obtained from Ega Chemie or Aldrich) is standardized before use.4... 

The reaction can be conducted with standard Schlenk techniques.7 All... 

All operations are performed under an atmosphere of nitrogen dried and deoxygenated as described in the procedure in Section A, using standard Schlenk techniques and a vacuum nitrogen line.9 1,2-Dimethoxyethane solvent is distilled from sodium benzophenone ketyl, under nitrogen atmosphere. 

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