Hydrides also

Flanagan and Oates [1] have extensively reviewed the thermodynamics of intermetallic hydrides also recommended are the classic work of Libowitz [2] and the com-... 

For reviews of organotin hydrides, see Neumann, W.R Synthesis, 1987,665 Kuivila, H.G. Synthesis, 1970,499, Acc. Chem. Res., 1968,1,299. Tributyltin hydride also reduces vinyl halides in the prescence of a palladium catalyst. See Uenishi, J. Kawahama, R. Shiga, Y Yonemitsu, O. Tsuji, J. Tetrahedron Lett., 1996, 37, 6759. 

The use of trimethylsilyl-based electrophilic catalysts with organosilicon hydrides also promotes the conversion of aldehydes into ethers and avoids the need to employ the potentially hazardous trityl perchlorate salt.314,334,338 One reagent pair that is particularly effective in the reductive conversion of aldehydes into symmetrical ethers is a catalytic amount of trimethylsilyl triflate combined with either trimethylsilane, triethylsilane, PMHS,334 or 1,1,3,3-tetramethyldisiloxane (TMDO, 64) as the reducing agent (Eq. 179).314 Either... 

Reduction of o /i-unsatin-ated lactams, S,6-dihydro-2-pyridones, with lithium aluminum hydride, lithium alkoxyaluminum hydrides and alane gave the corresponding piperidines. 5-Methyl-5,6-dihydro-2-pyridone (with no substituent on nitrogen) gave on reduction with lithium aluminum hydride in tetrahydrofuran only 9% yield of 2-methylpiperidine, but l,6-dimethyl-5,6-dihydro-2-pyridone and 6-methyl-l-phenyl-5,6-dihydro-2-pyridone afforded 1,2-dimethylpiperidine and 2-methyl-1-phenylpiperidine in respective yields of 47% and 65% with an excess of lithium aluminum hydride, and 91% and 92% with alane generated from lithium aluminum hydride and aluminum chloride in ether. Lithium mono-, di- and triethoxyaluminum hydrides also gave satisfactory yields (45-84%) [7752]. 

F yridinium oxime 394 in the presence of concentrated EECl gives oxazepine 395 in 61% yield (eqnation 172) . Beckmann rearrangement of 4-chromanone oximes in the presence of polyphosphoric acid or diisobntylalnminium hydride also afforded substituted benzoxazepinone ring. 

Tri-/ -butyltin hydride also serves as a hydrogen-atom donor in radical-mediated methods for reductive deoxygenation of alcohols.131 The alcohol is converted to a thiocarbonyl derivative. These thioesters undergo a radical reaction with tri-w-butyltin... 

Reactions with alkali and alkaline earth metal hydrides also produce the same ionic metallic hydrazides ... 

The hydride also reacts with ammonia forming lithium amide and evolving hydrogen ... 

Magnesium hydride also is produced by thermal decomposition of diethyl-magnesium at 200° C ... 

Hydride also may be obtained by combining zirconium metal with hydrogen... 

Higher group IV hydrides also autoxidize readily. Since Curtice, Gilman, and Hammond have shown that the autoxidation of triphenyl-silane is a chain process (6), an initial hydroperoxide chain seems plausible. Trialkyltin hydrides similarly take up oxygen on exposure to air (13), yielding species with Sn—O bonds, but the reactions have not been studied in much detail. 

Dr. Halpern Yes, as a first approximation, subject to the question of whether the hydride also exchanges with the solvent. 

Figure F shows some acetylene insertion reactions. These, too, are similar to the olefin insertion reactions. The manganese and cobalt hydrocarbonyls again add. Chloronickelcarbonyl hydride, which I believe is an intermediate in many of the nickel carbonyl-catalyzed reactions, adds to olefins. Diborane and the aluminum hydrides also add.

From the standpoint of laboratory-scale preparations, probably the most commonly used method is the reduction with zinc in a sodium hydroxide medium. The use of lithium aluminum hydride also merits consideration. 

The binuclear hydride salts are air sensitive, soluble in THF, acetone, CH3CN, MeOH, and diethyl ether, and insoluble in hydrocarbon solvents. They can be stored cold under an inert gas or in vacuo for several months. The salts tend to slowly decompose into W(CO)6 and [PPN] [FeH(CO)4], Carbon monoxide rapidly (within minutes) degrades the dimer into the same products.5 The salts react rapidly with CH3COOD or stronger deuterated acids to form the H-D exchanged products, [FeCrD(CO)9]. The hydrides also act as catalysts in olefin isomerization.10... 

This volume summarizes recent results of some of the leading investigators in trahsition metal hydride research. Readers interested in more extensive background material are urged to consult some of the many excellent books on the subject, such as Transition Metal Hydrides edited by E. L. Muetterties (Marcel Dekker, Inc., New York, 1971), which covers covalent metal hydride complexes, and Metal Hydrides edited by W. M. Mueller, J. P. Blackledge, and G. G. Libowitz (Academic, New York, 1968), which comprehensively covers work in binary and ternary metal hydrides. Also available in the covalent metal hydride area are excellent reviews by Ginsberg [Transition Metal Chemistry (1965) 1,112], and Kaesz and Saillant [Chemical Reviews (1972) 72, 231]. In this book we have not tried to be comprehensive rather, our purpose is to update recent developments in both major areas of metal hydride research. 

Metal hydrides, such as lithium aluminum hydride, also can be used to reduce derivatives of carboxylic acids (such as amides and nitriles see Table 16-6) to aldehydes. An example follows ... 

EXTENSIONS AND COMMENTARY There are about twenty different synthetic routes in the literature for the preparation of MDA. Many start with piperonal, and employ it to make methylenedioxyphenylacetone or a mcthylcnedioxydihydro-cinnamic acid amide instead of the nitrostyrene. The phenylacetone can be reduced in several ways other than the cyanoborohydride method mentioned here, and the amide can be rearranged directly to MDA. And there are additional methods for the reduction of the nitrostyrene that use no lithium aluminum hydride. Also there are procedures that have safrole or isosafrole as starting points. There is even one in the underground literature that starts with sassafras root bark. In fact, it is because safrole is one of the ten essential oils that MDA can humorously be referred to as one of the Ten Essential Amphetamines. See the comments under TMA. 

Acrylonitrile and tributyltln hydride were obtained from the Aldrich Chemical Company, Inc., and used without further purification. The use of a large excess of acrylonftrile reduced the amount of reduction by-product (2,3, 4, 6-tetraacetyl-1, 5-anhydroglucitol). Because tributyltln hydride also reacts with acrylonitrile, a small excess must be used. 

This is analogous to the previously described method (Section II,A,2) for making bridging-dinitrogen complexes. Metal chlorides and hydrides also react with nitriles to yield imido complexes, as shown in reaction (77) (6, 165, 280). 

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