Alcohols hydride

Nucleophilic addition reactions of aldehydes and ketones (a) Addition of hydride alcohols (Section 19.7)... 

Lithium aluminum hydride Alcohols, aldehydes, ketones, esters, epoxides. 

Experimentally, this pathway has been well established from IR spectra of the [CpRuH(C0)(PCy3)]/(CF3)30H system in CH2CI2, where large variations in hydride/alcohol ratios did not affect slow transformation of the H H complexes to hydrogen-bonded ion pairs with k values between 1.4 X 10 and 1.6 X 10 s [25]. Activation parameters for this step (Table 10.3) have been determined in hexane [6]. It is probable that a similar mechanism operates for protonation of the hydrides [ReH2(NO)(CO)(PR3)2] with CF3COOH (Table 10.3) in CD2CI2, where the reaction corresponds to first-order kinetics on the acid at hydride/acid ratios > 1 [7]. 

The use of sulfur dioxide as the solvent and low temperatures allows efficient and clean formation of the a-chloro nitroso compound4 6. The primary adducts, containing nitroso, nitro, or oxime functions, can be reduced to chlorine-free amines or /i-chloro amines 8. Additionally, chlorine readily undergoes substitution by nucleophiles (hydrides, alcohols, amines, etc.), such that halogen-free and /i-functionalized nitroso and nitro compounds, which can further be reduced to amines, can be prepared by this route. Recently, the conversion of nitroso compounds (RNO) to amines (RNHEt) using a triethylborane/borane mixture has been described9 10, although not applied specifically to /i-chloro nitroso compounds. 

Let us look a little more closely at reduction by metal hydrides. Alcohols are formed from carbonyl compounds, smoothly and in high yield, by the action of such compounds as lithium aluminum hydride, LiAlH4. Here again, we see... 

Use For chemical reactions where advantages of controlled reaction rate, lower reaction temperature, increased yields, or substitution for more expensive reagent can be achieved, as in, removal of sulfur from hydrocarbons and petroleum, metal powders, sodium hydride, alcohol-free alcoholates, phenylso-dium. 

Lactams may be converted to the corresponding nylons by water-initiated polymerization. The reaction may also be initiated by a base that requires anhydrous conditions and proceeds at high reaction rates [9,10]. Initiators used include carbonates, hydrides, alcoholates, and hydroxides of alkali and alkaline earth metals. The conversion of lactams to polyamides is also possible by a cationic process, entailing initiation in an anhydrous medium by either strong protonic acids or their dissociable salts [11]. 

Diisobutylaluminum hydride Alcohols from carboxylic acid esters... 

Ferrous chloride/sodium hydride Alcohols from oxo compounds under mild conditions... 

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