Hydrazones benzoyl

N-Benzoyl hydrazones 40, derived from aromatic and aliphatic aldehydes, undergo allylation with AllylSiCl3 in DMF at 20 °C [42] or in CH2C12 with excess of DMSO or Ph3PO as activator at —78 °C (Scheme 7.6) [43]. Three equivalents ( ) of... 

AUylation. Scandium(III) triflate promotes allylation of aldehydes (in the presence of ketone moieties) with allylgermanium reagents in aqueous nitromethane. By adding primary amines as the third component, such reactions deliver homoallylic amines (in such cases the aldehydes react too slowly to cause any chemoselectivity problem) Benzoyl hydrazones react accordingly. ... 

A variety of other monoanionic ligands that contain O and N functional groups have been reported to complex Zr and Hf. For example, hydroxy-pyridionate,707 substituted-thiazolidin-4-ones,708,709 cycloserine,710 V-furfurylidnearylamines711 azopyrazolones,712-714 substituted aroylhydrazone,715 benzoyl hydrazones,716-718 6-amino-penicillinic acid,719 aniline-carboxylate,720 aminoantipyrine,721 and bis-salicyloyl hydrazides722 have been employed in the preparation of various halide and oxide derivatives. The majority of these complexes have been characterized by IR spectroscopy and elemental analysis alone. 

The benzoylated hydrazone resin (150 mg, 0.11 mmol) was suspended in 6 mL dichloroethane/trifluoroacetic acid (1/1). Then 10 eq. laevulinic acid was added, and the mixture was heated for 15 min to 2 h at 70°C. After cooling, the mixture was quenched with methanol, and the resin was filtered and washed with 5 mL dichloromethane, methanol, ethyl acetate, and methanol. The filtrate was evaporated to dryness, and the crude product was purified by preparative HPLC. Finally, [l-(4-bromobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetic acid was obtained as white solid, in a yield of 57% with a purity of > 99% (HPLC), m.p. 15rC. 

Scheme 7.46 NHC-catalyzed asymmetric cross-annulation of enals and N-benzoyl hydrazones reported by Scheldt.

The mechanisms of the primary amine-thiourea-catalyzed Michael additions of ketones to nitroolefins [184] and of Mannich additions of ketones to A -benzoyl hydrazones [185] have been theoretically studied by Tsogoeva and co-workers. While in the first case the calculations support a transition state according to the conceptual framework of Figure 2.42, involving an enamine intermediate (Figure 2.44A), in the second one the calculations provide evidence in favor of a nonconventional enol mechanism (Figure 2.44B) [186]. 

FIGURE 2.44. Transition state models for (A) the primary amine-thiourea-catalyzed Michael additions of ketones to nitroolehns and (B) Mannich additions of ketones to A-benzoyl hydrazones. 

IR data for the dinuclear compound [V0(L)]2(p-0), where H2L = salieyal-dehyde benzoyl hydrazone, show that the hydrazone ligand is tridentate, via two O atoms and one N." Metal (VO +, U02 +, Cd(II), Ni(II), Cu(II), Zn(II) or Hg(II)) complexes with 5-chloro-7-iodo-8-quinohnol, have IR spectra showing ligand coordination via the quinoline ring N and hydroxyl O atoms." ... 

C24H15CI3M0N6S3, (p-Chlorothiobenzoyl-hydrazone-diyl)-(p-chlorothio-benzoyl-hydrazone-triyl)-(N -isopropylidene-p-chlorothiobenzoyl-hydrazone)molybdenum, 45B, 1313 C24H16Cl2Hg02S2, Dichlorobis(phenoxathiin)mercury, 34B, 589 C24H16Cl6PtS2, cis-Dichlorobis(4,4 -dichlorodiphenyl sulfide)platin-um(II), 37B, 635... 

Stoichiometric asymmetric allylation of (V-benzoyl hydrazones derived from aromatic and heteroaromatic aldehydes can be attained with pseudoephedrine chelates derived from allyl and ( )- and (Z)-crotyl trichlorosilanes with excellent diastereo- and enantioselectivity (eq 7) note the opposite relative configuration at the vicinal centers of the product compared to that obtained in the aldehyde allylation (eq 4), resulting from different orientation in the transition state. ... 

Aryl- and benzoyl-hydrazones of 2,4-0-ethyIidene-D-erythrose have been prepared and acetylated. D- /> cero-Tetrulose phenyl- and 4-substituted-phenyl-osazones (prepared from D-erythrose) gave l-aryl-3-formylpyrazoIe A-acetylarylhydrazones on boiling with acetic anhydride (Scheme 36). The... 

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