Product of reductive

Product of reduction of carbonyl compound by specified reducing agent... 

K. S. Bengston, A Technical Comparison of Six Processes for the Production of Reduction Grade Mlumina from Non-Bauxite Raw Materials, Light Metals, AIME Annual Meeting, New Orleans, 1979. 

These reductions are not important for preparative purposes. The same can be said for reductions with LiAlH4, and with hydrogen over a catalyst, converting diaziridines to a mixture of amines including products of reductive amination of the former carbon atom of the diaziridine ring. 

Analogous acyl migrations occur with dienol acetates of type (238) and (239), yielding products from the two possible recombinations—(240)/(241) and (243)/(244), respectively—besides the products of reductive acetyl elimination (see Experiment b below). 

A direct test of this mechanism is awaited. Haim S" notes that the primary Fe(III) product of reduction of /ra s-Co(NH3)4(OH2)N3 + should be detectable using a suitable flow apparatus. 

The immediate product of reduction is N02 which disproportionates to N03 and NO however, the latter is very rapidly reduced by further Mo(V) to NO. 

Fig. 10 Structures of isosaraine-1 (48) and -2 (49) and the respective products of reduction with NaBH4, 50 and 51...

SCHEME 7.7 Products of reductive activation of a simplified WV-15 analogue. The 13C labels are designated with asterisks ( ). 

Open-chain vicinal dihalides are apparently reduced conceitedly via a conformation in which the two halogen atoms are anti to each other. This conclusion is based upon the fact that meso isomers of structures 47 ait generally more easily reduced than the dl isomers, presumably because steric repulsions are less for meso than for dl in the transition state for electron transfer. The stereochemistry of the products of reduction of simple open chain vicinal di-... 

Many polypyridyl metallic complexes have been used successfully as electrocatalysts in homogeneous and heterogeneous systems and generally CO and 11 COO are the main products of reduction. Among these, the two complexes, [Re(bpy)(CO)3Cl] and [Ru(bpy)2(CO)X]" + (X = CO, Cl, H 11 2 or 1), have attracted much attention because of their characteristic... 

Several other polypyridyl metal complexes have been proposed as electrocatalysts for C02 reduction.100-108 For some of them HCOO- appears as the dominant product of reduction. It has been shown for instance that the complexes [Rhin(bpy)2Cl2]+ or [Rh n(bpy)2(CF3S03)2]+ catalyze the formation of HCOO- in MeCN (at —1.55 V vs. SCE) with a current efficiency of up to 80%.100,103 The electrocatalytic process occurs via the initially electrogenerated species [RhI(bpy)2]+, formed by two-electron reduction of the metal center, which is then reduced twice more (Rlr/Rn Rh°/Rh q. The source of protons is apparently the supporting electrolyte cation, Bu4N+ via the Hoffmann degradation (Equation (34)). 

The only possible product (of reduction) at the cathode is the following. 

In contrast to the nickel-organozinc catalyst system, which induces /3,/3-coupling of bis(enones), the use of cobalt(ll) catalysts in the presence of silane results in a,/3-coupling to provide products of reductive Michael cyclization.48,48a,48b Both five- and six-membered ring products 26b and 25d are formed in good yields and with complete diastereoselection. The choice of silane is critical. Whereas exposure of bis(enone) 25a to Co(dpm)2... 

The products of reductive cyclization incorporate two non-exchangeable hydrogen atoms. Homolytic and heterolytic hydrogen activation pathways may now be discriminated on the basis of hydrogen-deuterium crossover experiments. Reductive cyclization of the indicated nitrogen-tethered enyne under a mixed atmosphere... 

In the case of t-butyl acetate, shown in reaction 41, three successive geminal hydrogen abstractions and insertions of 303 take place a product of reductive dimerization (306) is also formed in small yield626. 

A. Pielesz, I. Baranowska, A. Rybak and A. Wochowicz, Detection and determination of aromatic amines as products of reductive splitting from selected azo dyes. Ecotox. Environ. Saf., 53 (2002) 42 17. 

Side products of reductive C-C bond formation have been observed in catalytic hydrogenation on rare occasions, see [20, 21]. 

CoH(CN)5] catalyses the hydrogenation of nitro compounds either to amines (aliphatic substrates) or to products of reductive dimerization, i.e. to azo and hydrazo derivatives. Ketoximes and oximes of 2-oxo-adds are hydrogenated to amines. This latter reaction gives a possibihty to directly produce a-amino-acids in the reductive amination of 2-oxo-acids in aqueous ammonia at a temperature of40-50 °C and 70 bar H2 (Scheme 3.1). Yields are usually high (approximately 90%) [18]. 

Anion-radicals are the first products of reductive electron transfer. Mntnal repulsion of the primary and snbseqnent excess electrons forms the basis of the impediment of polyelectron reduction at the initial step. However, an orbital, which already has one electron, can be populated by another electron if a proper redncer is chosen. This reducer must be able to overcome Coulomb repulsion. As a resnlt, more or less stable dianions are formed. Like anion-radicals, dianions can reversibly give excessive electrons back. If skeleton rearrangement is absent, the initial uncharged molecules are regenerated. 

Reaction of the products of reduction with lithium aluminum hydride with water is very exothermic. This is especially true of reductions in which an excess of lithium aluminum hydride has been used. In such cases it is advisable to decompose the unreacted hydride by addition of ethyl acetate (provided its reduction product - ethanol - does not interfere with the isolation of the products). Then normal decomposition with water is carried out followed by acids [5i] or bases [121]. 

Reductions of alkyl pyridones with lithium aluminum hydride or alane are very complex and their results depend on the position of the substituents and on the reducing reagent. Since the pyridones can be viewed as doubly unsaturated lactams with a,/J- and )i, -conjugated double bonds, the products result from all possible additions of hydride ion 1,2,1,4 or 1,6. Consequently the products of reduction are alkylpiperidines and alkylpiperideines with double bonds in 3,4 or 4,5 positions [449, 7755]. 

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