Sodium formate hydrogen donor

Other salts of formic acid have been used with good results. For example, sodium and preferably potassium formate salts have been used in a water/organic biphasic system [36, 52], or with the water-soluble catalysts discussed above. The aqueous system makes the pH much easier to control minimal COz is generated during the reaction as it is trapped as bicarbonate, and often better reaction rates are observed. The use of hydrazinium monoformate salts as hydrogen donors with heterogeneous catalysts has also been reported [53]. 

The BuMines process involves the reduction of cellulosics with carbon monoxide, water and a sodium carbonate catalyst. A formate is produced, which, it is thought, acts as a hydrogen donor to reduce the feed. The following mechanism has been proposed (13) ... 

Sodium borohydride (160) was found to serve as a hydrogen donor in the asymmetric reduction of the presence of an a,pi-unsaturated ester or amide 162 catalyzed by a cobalt-Semicorrin 161 complex, which gave the corresponding saturated carbonyl compound 163 with 94-97% ee [93]. The [i-hydrogen in the products was confirmed to come from sodium borohydride, indicating the formation of a metal enolate intermediate via conjugate addition of cobalt-hydride species (Scheme 2.17). 

Iridium-monotosylated ethylenediamine [Ts(en)] and Ir-CF3Ts(en) are highly active and chemoselective catalysts for the aqueous-phase transfer hydrogenation of aldehydes using sodium formate as the hydrogen donor.376... 

In the absence of a laboratory or industrial pressure vessel, catalytic hydrogentransfer is a viable alternative. Here, the nitro compound is stirred in a solvent with a catalyst, commonly 1% platinum on carbon, in the presence of a hydrogen donor such as hydrazine, sodium formate (sodium methanoate) or methylcyclohexene (Scheme 7.6). In the case of hydrazine, interaction at the catalyst surface produces the reductant, hydrogen, and nitrogen. Toluene is the by-product when methylcyclohexene is used. 

Homogeneous catalytic hydrogenation over tetrakis(triphenylphosphine)palladium using hydrogen or sodium formate as hydrogen donors converts p-bromostyrene to styrene in 37% and 35% yields respectively (the other products being polymers) ... 

Alcohols or phenols protected by benzyloxycarbonyl groups are very smoothly reduced over Pd/C using phosphinic acid or sodium phosphinate as hydrogen donor. Effective cleavage of an allylic r-amine has been demonstrated (equation 16) utilizing ammonium formate as donor. The lack of tegiospeci-ficity could possibly be overcome by selective use of catalysts. For example, double bond migration can be influenced by Pd/Hg or Pd/Pb catalysts. ... 

Aldoses (D-mannose, D-glucose) were also reduced to the corresponding alditols in water in the presence of RuCl2(tppts)3 as the catalyst with sodium formate, or an azeotropic mixture of formic acid and triethylamine, as the hydrogen donor [17]. 

Hydrodehalogenation of aliphatic or benzylic halides were catalyzed by water soluble ruthenium phosphine complexes in the presence of sodium formate as hydrogen donor [194], Hydroxycarbonylations could also be performed with high palladium catalyst activities in biphasic systems [195-197]. 

The reductive animation of 3-oxo-l,2.3.4-tetrahydrocarbazole with (S)-phenylethylamine and sodium borohydride leads to (37 )-3-[(l.S )-phenylethylamino]-l,2,3,4-tetrahydrocarbazole in 39.7% yield. The cleavage of the phenylethyl group is accomplished by a transfer hydrogenation, with ammonium formate as a hydrogen donor and palladium on charcoal as a catalyst, to give the enantiomerically pure (3/ )-3-amino-l,2,3,4-tetrahydrocarbazole23. 

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