Potassium triethylborohydride Sodium borohydride

Alkyl bromides and especially alkyl iodides are reduced faster than chlorides. Catalytic hydrogenation was accomplished in good yields using Raney nickel in the presence of potassium hydroxide [63] Procedure 5, p. 205). More frequently, bromides and iodides are reduced by hydrides [505] and complex hydrides in good to excellent yields [501, 504]. Most powerful are lithium triethylborohydride and lithium aluminum hydride [506]. Sodium borohydride reacts much more slowly. Since the complex hydrides are believed to react by an S 2 mechanism [505, 511], it is not surprising that secondary bromides and iodides react more slowly than the primary ones [506]. The reagent prepared from trimethoxylithium aluminum deuteride and cuprous iodide... 

Potassium triethylborohydride, 260 Sodium borohydride, 21 Ring-forming reactions 2,2 -Dihydroxy-1,1 -binaphthyl, 113 Other asymmetric reactions Camphor-10-sulfonic acid, 62 Di-jjL-chlorobis(l,5-cyclooctadiene)di-rhodium-2,3-0-Isopropylidene-2,3-dihydroxy-1,4-bis(diphenyl-phosphine)butane, 153... 

Potassium triethylborohydride, 260 Samarium(II) iodide, 270 Sodium-Alcohol, 277 Sodium borohydride, 21, 167 Sodium cyanoborohydride-Tin(II) chloride, 280... 

Numerous reducing agents were tried at this point unsuccessfully. For example, lithium aluminum hydride destroyed the substrate, whereas DIBAH or lithium borohydnde in THF and sodium borohydride in ethanol led to reduction of the quinoline system. On the other hand, both potassium borohydride (either with or without 18-crown-6) and zinc borohydride (with or without ethanol) produced no reaction at all. Lithium triethylborohydride resulted in de-methoxylation, and sodium borohydride in refluxing THF gave a 45% yield of diol 16 together with overreduced product. 

Henkel-Loctite appears to have been careful to avoid the patent minefield laid by 3M and Dow. Their patent strategy in this field has involved mainly the use of metal alkali borohydrides [113,114], or tetralkylboranes [115-117]. In particular, alkali metal trialkyl borohydrides are used, the alkali metal salt being selected from lithinm triethylborohydride, sodium triethylborohydride, potassium triethylborohydride, lithium tri-sec-butylborohydride, sodium tri-sec-butylborohydride, potassium tri-sec-butylborohydride, and lithium triethylborodeuteride. 

Replacement of hydrogen by alkyl groups gives compounds like lithium triethylborohydride (Super-Hydride ) [100], lithium tris sec-butyl)borohydride [101] (L-Selectride ) and potassium tris sec-butyl)borohydride (K-Selectride ) [702], Replacement by a cyano group yields sodium cyanoborohydride [103], a compound stable even at low pH (down to 3), and tetrabutylammonium cyanoborohydride [93],... 

In aprotic solvents, such as dichloromethane and THF, potassium boro-hydride [10], lithium borohydride [8b], lithium triethylborohydride [8a, 11], and diisobutylaluminum hydride (DIBALH) [11] have been used instead of NaBH4. NaBH4 also reduces elemental selenium in alcohol or water to sodium hydrogen selenide or sodium diselenide (Na2Se2) depending on the stoichiometry of the reactants (Scheme 8) [12]. These anions are useful for the synthesis of selenides or diselenides, respectively, via nucleophilic substitution with various electrophiles. 

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