Reducing agents compounds

The anionic alkoxy hydrides of boron and aluminum, HM(OR)3 , have been used as organic reducing agents. Compounds such as these are intermediates in reactions involving the tetrahy-drides and carbonyl groups. 

In order to allow polymerisation at low ambient temperatures, the promoted-catalytic method may be used. This is achieved by promoters which are reducing agent compounds... 

Hi at 500" C. Stable crystalline compound, gives LiOH and Hi with water (may ignite in moist atmosphere). Used as a source of Hi, as a reducing agent, and for the preparation of hydrides. 

The most abundant literature is that bearing on solar eneigy conversion, mainly centered on the use of Ru(2,2 -bipyridine)3 and its analogues. The excited state of the parent compound was found some years ago to be a powerful reducing agent [212], allowing the following spontaneous reactions to be written ... 

LiAlH4, lithium tetrahydridoaluminate ("lithium aluminium hydride . so-called) is an excellent reducing agent in ether solution for both organic and inorganic compounds it may be used to prepare covalent hydrides SiH ether, for example... 

It is a colourless gas which decomposes on heating above 420 K to give metallic tin, often deposited as a mirror, and hydrogen. It is a reducing agent and will reduce silver ions to silver and mercury(II) ions to mercury. SnSn bonding is unknown in hydrides but does exist in alkyl and aryl compounds, for example (CH3)3Sn-Sn(CH3)3. 

Mercury(I) compounds in solution give a white precipitate with chloride ion. blackened by ammonia (p. 437) alkalis and reducing agents generally produce black or grey mercury from mercury(I) compounds. 

C2H5ONO + NaOH C2H5OH + NaNOa sodium nitrite. The second compound is nitroethane, C,H NO, of b.p. 114° its identity is clearly shown by the action of reducing agents, which convert it into ethylamiiie, CjHjNHj, thus proving the presence of a nitrogen carbon... 

Formation of silver mirror or precipitate of silver indicates reducing agent. (This is often a more sensitive test than I (a) above, and some compounds reduce ammoniacal silver nitrate but are without effect on Fehling s solution.) Given by aldehydes and chloral hydrate formates, lactates and tartrates reducing sugars benzoquinone many amines uric acid. 

Common reducing agents are hydrogen in the presence of metallic or complex catalysts (e.g. Ni, Pd, Pt, Ru, Rh), hydrides (e.g. alanes, boranes, LIAIH, NaBHJ, reducing metals (e.g. Li, Na, Mg, Ca, Zn), and low-valent compounds of nitrogen (e.g. NjHj, NjHJ, phosphorus (e.g. triethyl phosphite, triphenyiphosphine), and sulfur (e.g. HO-CHj-SOjNa = SFS, sodium dithionite = Na S O. ... 

Triethylammonium formate is another reducing agent for q, /3-unsaturated carbonyl compounds. Pd on carbon is better catalyst than Pd-phosphine complex, and citral (49) is reduced to citronellal (50) smoothly[55]. However, the trisubstituted butenolide 60 is reduced to the saturated lactone with potassium formate using Pd(OAc)2. Triethylammonium formate is not effective. Enones are also reduced with potassium formate[56]. Sodium hypophosphite (61) is used for the reduction of double bonds catalyzed by Pd on charcoal[57]. 

Formic acid is a good reducing agent in the presence of Pd on carbon as a catalyst. Aromatic nitro compounds are reduced to aniline with formic acid[100]. Selective reduction of one nitro group in 2,4-dinitrotoluene (112) with triethylammonium formate is possible[101]. o-Nitroacetophenone (113) is first reduced to o-aminoacetophenone, then to o-ethylaniline when an excess of formate is used[102]. Ammonium and potassium formate are also used for the reduction of aliphatic and aromatic nitro compounds. Pd on carbon is a good catalyst[103,104]. NaBH4 is also used for the Pd-catalyzed reduction of nitro compounds 105]. However, the ,/)-unsaturated nitroalkene 114 is partially reduced to the oxime 115 with ammonium formate[106]... 

Dibal IS an informal name given to the organometallic compound [(CH3)2CHCH2l2AlH used as a reducing agent m certain reactions Can you figure out the systematic name from which dibal IS denved" ... 

Much of the chemistry of diols—compounds that bear two hydroxyl groups—is analo gous to that of alcohols Diols may be prepared for example from compounds that con tain two carbonyl groups using the same reducing agents employed m the preparation of alcohols The following example shows the conversion of a dialdehyde to a diol by... 

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

Many naturally occurring substances are epoxides You have seen two examples of such compounds already m disparlure the sex attractant of the gypsy moth (Section 6 18) and m the carcinogenic epoxydiol formed from benzo[a]pyrene (Section 118) In most cases epoxides are biosynthesized by the enzyme catalyzed transfer of one of the oxy gen atoms of an O2 molecule to an alkene Because only one of the atoms of O2 is trans ferred to the substrate the enzymes that catalyze such transfers are classified as monooxy genases A biological reducing agent usually the coenzyme NADH (Section 15 11) is required as well... 

Almost any nitrogen containing organic compound can be reduced to an amine The syn thesis of amines then becomes a question of the availability of suitable precursors and the choice of an appropriate reducing agent... 

A variation of the classical reductive amination procedure uses sodium cyanoboro hydride (NaBH3CN) instead of hydrogen as the reducing agent and is better suited to amine syntheses m which only a few grams of material are needed All that is required IS to add sodium cyanoborohydride to an alcohol solution of the carbonyl compound and an amine... 

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