Reductions Catalyzed by Copper Hydride

General procedure for reduction of saturated ketones using [(Ph3P)CuH]6 and Me2PPh 

Under an inert atmosphere, a solution of the substrate in benzene was added to a slurry of freshly purified CuCl (5 mol%), Me2PPh (6 equiv./Cu), and t-butanol (10 equiv./Cu) in benzene (final concentration 0.4-0.8 M in substrate). After degassing with one freeze-pump-thaw cycle, the suspension was placed under a slight positive pressure of hydrogen and allowed to stir until completion, as monitored by TLC. The product was isolated and purified as described above. 

Representative 1,2-reduction/silylation of an aldehyde, giving (2-bromobenzyloxy)-diphenylmethylsilane [44] 

A dried 25 mL flask with a rubber septum top was flushed with argon and charged with [PPh3(CuH)]5 (53 mg, 0.162 mmol), as a red solid. Toluene (5.4 mL) was added, followed by neat diphenylmethylsilane (1.4 mL, 

A dvied 25 mL flssk wdtli s laibbev septum lop wss flushed wdlb svgon snd disvged wdtli [PPbjICuHjIc I53 mg, 0.1G2 mmolj, ss s ved solid. Toluetie I5.4 mLj wss sdded, followed by nesL dipbenylmeibylsilstie I1.4 mL, 

Ketones lake cotisidetably longer lo reduce tlian aldeliydes flO-24 b), altlioiigli yields are nol compromised. Differences in reaclivity loward aldebydes and ketones can be used lo advantage, witli biglily diemoselective reduction occurring al tlie aldebyde in tlie presence even of a metliyl ketone fEq. 5.22) [44]. 

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The introduction of a polyfluorinated chain is not so easy as that of an alkyl chain. Transition metal catalyzed cross-coupling of Grignard reagents and organozinc compounds are inefficient in the synthesis of polyfluorinated 3-alkylthiophene. The copper-catalyzed perfluoroalkylation results in the formation of 2-and 3-substituted thiophenes, which are difficult to separate from each other. The reaction of fluorinated alkylmagnesium iodide with 3-formylthiophene, follwed by reduction with lithium aluminum hydride, gave (22) in an overall yield of 40% [27]. 

Voigtritter KR, Isley NA, Moser R, Aue DH, Lipshutz BH (2012) Regioselective reductions of P, p-disubstituted enones catalyzed by nonracemically ligated copper hydride. Tetrahedron 68 3410-3416. doi 10.1016/j.tet.2011.10.056... 

Electroless plating — An autocatalytic process of metal deposition on a substrate by reduction of metal ions from solution without using an external source of electrons. It is promoted by specific reductants, namely formaldehyde, sodium hypophosphide, sodium boro-hydride, dialkylamine borane, and hydrazine. Electroless deposition has been used to produce different metal (e.g., nickel, cobalt, copper, gold, platinum, palladium, silver) and alloy coatings. It can be applied to any type of substrate including non-conductors. Some substrates are intrinsic catalytic for the electroless deposition other can be catalyzed usually by sensibilization followed by Pd nucleation also, in some non-catalytic metallic substrates the electroless process can be induced by an initial application of an appropriate potential pulse. In practical terms, the evaluation of the catalytic activity of a substrate for the electroless deposition of a given metal is... 

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