Dimethylamine complexes

The Step 2 product (0.484 mmol) was treated with borane-dimethylamine complex (1.952 mmol) in 40 ml CH2C12 at 0°C followed by the dropwise addition of 254 ml boron trifluoride diethyl etherate over 30 minutes. Stirring was continued for an additional hour at ambient temperature and the mixture was then quenched with using 15 ml saturated NaHC03 solution. The solution was diluted with 60 ml CH2C12, then washed three times with 100 ml brine, dried, and concentrated. The residue was purified by flash chromatography using hexane/EtOAc, 6 1, and the product isolated in 60% yield. 

Oxidation (with such reagents as iron(III) chloride, potassium dichromate, silver oxide or nitrous acid) of 4,7-, 6,7-, and 5,6-dihydroxy-, and 5,6-dimethoxy-benzimidazoles gives the corresponding quinones. A 5-methyl group is oxidized by permanganate to carboxy (74CRV279). In the presence of copper(II)-piperidine or -dimethylamine complexes oxygen... 

The Aloe group can be used for protection of the a-amino group instead of Boc or Fmoc as it is orthogonal to the semipermanent benzyl- or ferf-butyl-type side-chain and linker protections. This Aloe protection can be useful when some features of the peptide or pseudopeptide prevent the use of bases or acids in the deprotection step. In model studies, pseu-dometaUic hydrides (tributyltin hydride and borane-dimethylamine complex), which are neutral reagents, have been used as aUyl scavengers. 

The UV spectral data (Table XV) also appear to support electron delocalization in 3-benzoborepin. A similarity between the spectra of 3-phenyl-3-benzoborepin and the isoelectronic ring system, benzotropylium ion, was reported. The spectrum of the dimethylamine complex of... 

Thus, treatment of 2-bromocyclohexanone (12a) with diraethylamine and titanium(IV) chloride gave 3-bromo-2-dimethylaminocyclohexene (13a) in 85% yield. Attack of the ti-tanium(IV) chloride-dimethylamine complex occurred rapidly and selectively on the carbonyl group, rather than on the secondary amine alone, which displaced the halogen. 

G. N. Patwari, T. Ebata, and N. Mikami, Evidence of dihydrogen bond in gas phase phenol-borane-dimethylamine complex, J. Chem. Phys. 113, 9885-9888 (2000). 

Reductions. iyn-Selective reduction of observed with borane-pyridine in the present predominate in the reduction with LiBHEt-.-C (Ph,P)4Pd catalyzes removal of the R SC the transformation of y,8-epoxy-o(,p-un.saiurj lers by the borane-dimethylamine complex Allyl group scavengers. In the solid-nitrogen by an (V-allyloxycarbonyl group can the presence of a borane-amine complex. 

Ph P)4Pd catalyzes removal of the R SO, group from aryl perfluorosulfonates and the transformation of 7,8-epoxy-a, 3-unsaturated esters " to 8-hydroxy-a,P-unsaturated esters by the borane-dimethylamine complex. 

The extremely broad functional group tolerance of the Pd-catalysed N-depro tection of Aloe groups was a crucial design feature in a synthesis of the epoxy-quinol core of the Manumycin family of antitumour antibiotics [Scheme 8,80]. Note the convenient generation of the Pd(0) catalyst in situ from reaction of dichlorobis(triphenylphosphine)palladium(ll) with tributylstannane. The use of sodium borohydride and borane dimethylamine complex is illustrated in Schemes 8,81 and 82 respectively. 

Borane, compd. with dimethylamine (1 1) Borane-dimethylamine complex. See Dimethylamine borane Borane, tributoxy-. See Tributyl borate Borates, tetra, sodium salt, anhydrous. See Sodium borate... 

In this instance the crystalline dimethylamine complex decomposes as it melts (44°). For the reasons already discussed in connection with the analogous aluminium compound Me2AlNMc2, dimethylaminomethyl-beryllium associates. Up to 50° it is a poly- or oligo-meric glass then it melts between 51 and 54°. As vapour or in solution it is a cyclic trimer 3.36. 

The 7V-methylbenzo[( e]quinoline 426 was prepared by trapping the insertion product of an internal alkyne with a tertiary dimethylamine. One methyl group is eliminated. The dimethylaminonaphthalene-Pd complex 427 is an active catalyst and other Pd compounds are inactive[290a]. 

A rather more complex amino alcohol side chain is accessible by a variation of the Mannich reaction. Taking advantage of the acidic proton in acetylenes, propargyl acetate (62) is condensed with formaldehyde and dimethylamine to give the acetylated amino... 

Diamino-substituted complexes of type 37 were first obtained by Fischer et al. [12] in two steps via the 1,2-addition-elimination product 34 from di-methylamine and 35 (Scheme 6). The (3-aminoallenylidene)chromium complexes 36, which can be prepared either from 33 [47,48] or directly from 35 [33], can also be transformed to l,3-bis(dialkylamino)-substituted complexes of type 37 (e.g., R2=z Pr) by treatment with dimethylamine in excellent yields [33]. Although the complex 37 is accessible by further reaction of the complex 34 with dimethylamine, and 34 itself stems from the reaction of 35 with dimethylamine, the direct transformation of 33 to 37 could not be achieved [12]. In spite of this, heterocyclic carbene complexes with two nitrogens were obtained by reactions of alkynylcarbene complexes 35 with hydrazine [49] and 1,3-diamines [50]. 

In contrast to other terminal alkynes, the lithiated dimethylaminoethyne 40 does not give the corresponding alkynylcarbene but the cyclopropenylidene complex 41 (Scheme 7) [51]. Further addition of dimethylamine to 41 affords the substitution product 42 in excellent yield. This 2,3-bis(dimethylamino-cyclopropenylidene)pentacarbonylchromium (42) is extremely stable, and it cannot be transformed to the corresponding carbonyl compound, 2,3-bis... 

We conclude that the major role of bacteria in the nitrosa-tion of dimethylamine is the reduction of nitrate to nitrite and the lowering of the pH of the medium. Furthermore, the complex medium Itself catalyzes nitrosation. The nature of this catalysis is not known, although it could be due to the presence of carbonyl compounds, cysteine, or a variety of other compounds which are known to catalyze nitrosation (17). 

Hydroaminomethylation of alkenes occurred to give both n- and /. so aliphatic amines catalyzed by [Rh(cod)Cl]2 and [Ir(cod)Cl]2 with TPPTS in aqueous NH3 with CO/H2 in an autoclave. The ratio of n-and /.soprimary amines ranged from 96 4 to 84 16.178 The catalytic hydroaminomethylation of long-chain alkenes with dimethylamine can be catalyzed by a water-soluble rhodium-phosphine complex, RhCl(CO) (Tppts)2 [TPPTS P(m-C6H4S03Na)3], in an aqueous-organic two-phase system in the presence of the cationic surfactant cetyltrimethy-lammonium bromide (CTAB) (Eq. 3.43). The addition of the cationic surfactant CTAB accelerated the reaction due to the micelle effect.179... 

The characterization and crystal structure of the dimer [Pt2( -dppm)3] (dppm = bis(diphenyl-phosphino)methane), first reported as a deep red complex in 1978, was described by Manojlovic-Muir et al. in 1986.11 The structure, the first of its type, is made up of two parallel and almost eclipsed trigonal-planar platinum moieties bridged by three diphosphine ligands. The Pf Pt separation is 3.0225(3) A, too long to be considered a bond.11 [Pt2(//-dppm)3] catalyzes the hydrogenation/reduction of carbon dioxide with dimethylamine to give dimethylformamide12 (Equation (1)) and the reverse reaction.13... 

Add to the reaction mixture an equal volume of the reducing agent borane-dimethylamine (BDA) complex, which was previously prepared in the reaction buffer at a concentration of 125 mg/ml. 

The MPT model was also reported to apply in a number other electroless metal deposition systems, including a) electroless Ni from a citrate-complexant solution with dimethylamine borane (DMAB) reductant, operated at pH = 7 (pH adjusted using NH4OH) and at a temperature (T) = 40 °C [33] b) electroless Au deposition [34] from a KAu(CN)2 containing solution, which utilized potassium borohydride... 

Agents produce dimethylamine [(CH3)2NH], carbon dioxide (C02), and complex organic compounds. 

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