Benzophenone-sodium complex

Cyclohexane (Phillips 99+ mole %) was purified by stirring over H SO then distilled from a sodium dispersion. Tetrahydrofuran (Fisher) was distilled from a sodium/benzophenone complex. 

General Methods. Methanol used in kinetic runs was distilled from sodium methoxide or calcium hydride in a nitrogen atmosphere before use. Freshly distilled cyclohexanol was added to the methanol in the ratio 6.0 ml cyclohexanol/200 ml MeOH and was used as an internal standard for gas chromatographic (GC) analysis. Benzaldehyde was distilled under vacuum and stored under nitrogen at 5°. Other aldehydes (purchased from Aldrich) were also distilled before use. The corresponding alcohols (purchased from Aldrich) were distilled and used to prepare GC standards. All metal carbonyl cluster complexes were purchased from Strem Chemical Company and used as received. Tetrahydrofuran (THF) was distilled from sodium benzophenone under nitrogen before use. 

This preparation requires 2 days. All manipulations are performed in Schlenk-type flasks under nitrogen dried over molecular sieves (4 A) and deoxygenated on catalyst BASF R3-11 (Imhoff Stahl). Tetrahydrofuran (THF) is dried over sodium benzophenone ketyl under N2. The complex Co2(CO)8 was purchased from Strem. 

Solvents were dried over sodium (light petroleum, bp 40-60°C, toluene) or sodium-benzophenone (diethyl ether, THF). Sodium amide, hexamethyl-disilazane, lithium triethylhydroborate(l —), and hydrogen tetrafluoro-borate(l —) diethyl ether complex were obtained from Aldrich and used as supplied. 

Tetrahydrofuran (THF) (80 mL, freshly distilled from sodium benzophenone ketyl) is added from a 250-mL Schienk flask to bis(acetonitrile)tetrachloro-molybdenum(IV) (20 g, 0.052 mole) in a 250-mL Schienk flask and the mixture is stirred rapidly for 2 hours to give a yellow suspension of tetrachlorobis-(tetrahydrofuran)molybdenum(IV). The complex is filtered through a Schienk filter, washed with THF (20 mL), and dried in vacuo (10 2 torr) at room temperature. The product is obtained as a microcrystalline orange-yellow powder in yields of 15-17 g, 63-71%. The product is not analytically pure. Anal. Calcd. for CbH1602C14Mo C, 25.1 H, 4.9. Found C, 26.5 H, 4.2. However, it is sufficiently pure for subsequent reactions. 

Dehydroprogesterone (1) was purchased from Sigma Chemical Company and used without further purification. Cuprous bromide-dimethyl sulfide complex was prepared according to House s procedure.2 Hexamethyl-phosphoramide, chlorotrimethylsilane, and triethylamine were purchased from Tokyo Kasei Kogyo Co., Ltd., Japan and distilled from calcium hydride (CaH2>. Tetrahydrofuran (THF) was distilled from sodium-benzophenone ketyl immediately prior to use. Methylene chloride was distilled from phosphorus pentoxide (P2O5). 

To make the reactive fulleride compound KeCeo in the Fe-Ceo synthesis, fullerenes and a slight excess of potassium were sealed in a glass tube under vacuum and heated for approximately four days at 250 °C. Both solid-state NMR and Raman spectroscopy were employed to determine that the KeCeo compound was in fact synthesized. The KeCeo product was then reacted in an inert atmosphere with cyclopentadienyl-iron-dicarbonyl-iodide (CpFe(CO)2l) in tetrahydrofuran (THF) to form the complex. The recovered product was dried in an inert atmosphere. Manipulations of air-sensitive materials were carried out in a glove box or using standard Schlenk techniques. THF was distilled just prior to use from sodium benzophenone ketyl. Ceo was obtained from Aldrich, and CpFeCCOjol was obtained from Strew. 

The 1 1 reaction of ZnR2 with a-imino ketones R N=C(R")C(0)R" leads to quantitative formation of the dinuclear complexes [ZnR /it-A,O-N(R)(R )C(R")=C(R"0O ]2- The crystal structure of the derivative 238 has been reported. The reaction of [ZnEt(Cp)] and Et2NCH2C02Et gives 239, probably through the intermediate 240. The sodium dialkylamidozincate [(tmeda)Na(/ir-Bu-t)(/ir-TMP)Zn(Bu-t)] reacts with benzophenone to give 241. ... 

The inconvenient of the sodium benzophenone catalyst is that it is not easy to determine the quantity of catalyst used since it is never isolated but simply generated from sodium and benzophenone in THF and the THF solution is used as it is. On the other hand, the quantities of Fe complexes are exactly known since they... 

From these data it is difficult to identify the true nature of the anionic species generated by the reduction, although, from the work of Shore et al. (33,34), it should be a dianionic complex. Indeed, treatment of [Ru3(CO) 2] with sodium benzophenone in Na/Ru molar ratios of 1/1, 1.5/1, 2/1, and 3/1 was shown to afford, respectively, [Ru6(CO) g] , [Ru4(CO),3] , [Ru3(CO), ] ", and [Ru4(CO),2] ". The preparation of more highly charged complexes was also patented, and it was claimed that these species are active for the hydroformylation reaction. Starting... 

This is one of several reactions of this type in which an organic negative radical-ion and its parent molecule react in the presence of an alkali metal. It is found, rather interestingly, that the rate coefficients depend on the nature of the metal. To account for this, it has been postulated that the metal is involved in a bridging role in the activated complex, e.g., dipy.. K" ". . dipy for the case of 2,2 -dipy-ridyl (dipy) A more extreme case of this association between the radical-ion and the ion of the alkali metal used to form it occurs in the reaction of benzophenone with its negative ion. The spectrum of (benzophenone)" in dme has many hyper-fine lines caused by the interaction of the free electron with the and, when the metal is sodium, the Na nuclei. When benzophenone is added, the structure, due to the proton interaction, disappears and only the lines associated with the sodium interaction remain. To account for this, it has been suggested that the odd electron moves rapidly over all the proton positions too fast for the lines characteristic of the electron in the different proton environments to be seen), but relatively slowly from one sodium nucleus to another. Seen another way, this means that the transfer of an electron from molecule to molecule is associated with the transfer of the cation . ... 

The salt metathesis reaction of sodium fluorenone ketyl with Cp 2ZrCl2 in THF produces the corresponding zirconium fluorenone ketyl complex 856657 which was structurally characterized (Scheme 215). In the case of sodium benzophenone ketyl, further reaction between the ketyl radical and a Cp ligand takes place to give finally the ring-metallated zirconocene bis(alkoxide) complex 857. 

HPLC grade nonpolar solvents, toluene and dichloromethane, were purchased from Aldrich. Toluene was distilled over sodium/benzophenone, and dichloromethane was distilled over calcium hydride. All solvents were stored under nitrogen, over molecular sieves. Water content in dried solvents was typically less than 1 mM. Potassium salts of transition-metal-substituted heteropoly complexes were prepared according to the methods published previously. The IR, UWVIS spectra, and Cyclic Voltammograms agreed... 

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