Hydride adducts

Fraser, N., N. N. Greenwood, and P. Straughan Aluminium Hydride Adducts of Trimethylamine Vibrational Spectra and Structure. J. Chem. Soc. [London] 1963, 3742. 

Metal hydride adducts 13 AlH3(NMe3), AlH3(NMe2Et), GaH3(NR3) Sources for III-V alloys where carbon must be avoided... 

Hydride adducts (31) may be formed by the reaction of 1,3-dinitrobenzene with potassium borohydride their treatment with phenyldiazonium salts leads to nitro group displacement yielding azo-coupled products (32). 

The borohydride reduction of BrRe(CO)s in the presence of PPhMe2 and HSnBu3 forms (CO)4Re(PMe2Ph)H. The tin hydride adduct could not be isolated, but upon water work-up a cyclic dirhenium distannoxane 86 was isolated264. 

Gimbert, Y., Amaud, R., Tabet, J.C. and de Hoffmann, E. (1998) Gas phase reaction of neutral carbon disulfide with its hydride adduct anion tandem mass spectrometry and theoretical studies. J. Phys. Chem., 102, 3732-7. 

The generation of the carbcxi-carbon double bond of unsaturated nitrogen heterocycles by the rDA reaction of cycloadducts that act as protected ethylenes has been accomplished. Azetines have been prepared by this method. Another example is the synthesis of l-methyl-3-pyrroline (201). By protecting the ethylene of N-methylmaleimide (199) with furan and then reducing with lithium aluminum hydride, adduct (200) was obtained (equation 86). Pyrolysis of adduct (200) at 250-300 C gave l-methyl-3-pyrroline (201) in 60% isolated yield. The ethylene moiety of N-substituted maleimides can also be generated via rDA reactions. Examples include the generation of N-phenylmaleimide (equation 87) and of N-acetoxymaleimide (equation 88). ... 

Reaction of 459 with cyanide or hydride leads to the nitrile derivative 465 and the hydride adduct 466, respectively (272). 

Although insertion of metals into C-H bonds of alkanes, alkenes, and aromatics has been known for a long time, the direct intermolecular insertion of a metal fragment into a C-H bond of an alkane to provide a stable alkyl hydride adduct was achieved only in 1982. The intermediate 16-electron, electron-deficient transition metal fragment (or metals such as Ir, Rh, Ru, etc.) was generated photochemically by the decomposition of the appropriate metal dihydride or metal carbonyl. 

Bergman and Janowicz showed " - that photolysis of [Cp (PMe3)IrH2] in a variety of alkane solvents gave the corresponding alkyl hydride adducts with elimination of H2 [Eq. (6.88)]. These adducts were also found to eliminate alkanes thermally at 110°C and exchange with other alkanes. 

JOC5279>. Oxasilacyclopentane (9), in combination with its hydride adduct, rapidly reduce carbonyl compounds. The hydride adduct alone is a selective reagent for the conjugate reduction of enones <90JA5342). 

Radical initiator 14.8.2.2. Cj2H3oCl2P2Pt CiS-PtCl2(PEt3)2 Formation of hydride adduct ... 

We would like to note that a related Lewis acid/base interaction with hydrides may also suffice the piupose of the assessment of basicity. The thermodynamic analyses of the hydride adduct formation with protic substrate is usually accomplished by spectroscopic investigations of their equilibria of formation (eq 7). 

Formation of hydride adduct 16, 14.3.2.2 Reaction with Mc2Hg 12, 5.8.2.11.2 trans-PtCl2(PEt,)2 Reaction with RMgCl 2, 1.10.8.4 Reaction with N2H4 2, 1.10.8.2 Reaction with KOH and McjCHOH 2, 1.10.8 [(CHjCHjljPJjPtCE... 

The discussion in the proceeding sections dealt with systems at equilibrium, but just as in the earlier example involving acetonitrile, it is possible to monitor the progress of these reactions by a combination of spectroscopic techniques. An interesting example is the reaction of 1 with acetophenone. One of a series of hydride NMR spectra taken as a function of time is shown in Figure 3. The first products observed were the meta- and para-aryl hydride adducts. Later the cis-methyl adduct developed, and finally, the trans-methyl adduct (barely visible in the figure) developed as the system approached equilibrium. 

This section deals with the reactions in which the formation of N-heterocycles proceeds through the Mannich-type cyclocondensations of anionic o-adducts of nitroarenes. The reactions of o-adducts with formaldehyde and primary amines result in 1,3-annelation of the piperidine ring to the core structure of nitroarenes. Depending on nitroarene structure, there are two main routes for these reactions to take (a) the o-adduct is formed via the addition of C-nucleophile to a nitroarene bearing the hydroxy group and (b) cyclocondensation of hydride adducts of nitroarenes, where the hydride ion acts as a nucleophile. At least two wcta-positioned nitro groups in aromatic ring are necessary for these reactions to proceed. Scheme 52 demonstrates both of these options. 

The data on the synthesis of azabicyclo[3.3.1]nonanes fused with azoles have recently been published [102-104]. The first step of the reaction is the formation of hydride adducts 125 by action of NaBHa (Scheme 61). These adducts undergo the Mannich condensation with formaldehyde and alkyl amines to give 3-R-l,5-dinitroa-zabicyclo[3.3.1]nonanes 126, fused with azole fragments across the C(7)-C(8) bond. 

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