Diformyl pyridines

Alfonso, Gotor, and coworkers have also affected diasteroeselective amplification from racemic libraries and achiral guests [4]. Mixtures of cyclohexyl-1,2-diamine (rac) and 2,6-diformyl-pyridine led to a mixture of homo- and heterochiral dimers, trimers, and tetramers (Fig. 5.4). The addition of Ba(II) slightly amplified the homochiral over the heterochiral dimer (1.6 1). Templafing with Cd(II) instead led to a preponderance of trimers, as evidence by ESI-MS. However, the large number of signals in the H and C NMR spectra indicated a heterochiral trimer. Amplification of the C -symmetric heterochiral trimer (Fig. 5.4) was confirmed by... 

The only other example of a Schiff base condensation with dipyridine to form a macrocyclic complex has been reported by Tasker et al.112) in which 2,6-diformyl-pyridine or 2,6-diacetylpyridine is condensed with 6,6 -dihydrazmo-2,2 -dipyridine (132) in the presence of zinc(II) to afford a pentagonal bipyramidal complex 133. The rigidity of the system results in an equatorial Ns donor set that is essentially planar water molecules occupy the axial positions. 

SCHEME 17.9 Synthesis of Borromean ring by Stoddart et al. using dynamic covalent chemistry with a bipyridine-containing ligand, diformyl pyridine and Zn(II) (top) and two representations of corresponding x-ray crystal structure. Zn atoms are shown as balls. H atoms are omitted for clarity (adapted from CCDC 231701). (Source Meyer, C. D. et al., Chem. Eur. J. 16 (2010) 12570-12581. With permission.)... 

Other dicarbonyl components, widely used in the examined syntheses, are 2,6-diformyl(acetyl)pyridines, for instance (3.161) [318] ... 

Schiff base macrocyclic complexes of lanthanides have been prepared by a metal-template condensation of a diamine and 2,6-diacetyl or 2,6-diformyl derivative of pyridine or p-cresol [74]. The yield of these complexes depends on the radius of the metal ion and the donor ability of the counterion [75]. The acetate anion gave high yields while chloride and perchlorate anions gave poor yields [76]. In general the template synthesis... 

An W-formylated dibenzodiazocine was isolated in some cases in very poor yield <1998J(P1)1257>. Using the same synthetic approach, a series of fused diazocines were obtained. Thus, the action of bis-Vilsmeier reagents derived from W,W -dimethyl-W,W -diformyl-4-phenylenediamine with 4-substituted AUV-dimethylanilines, the diben-zo[ ]benzo[l,2-/4,5-/]bis-l,5-diazocines were obtained <2000S640>. Benzo[2,3]pyrido[6,7-A]-l,5-diazocines were synthesized from a Vilsmeier reagent derived from 4-W-(methylformamido)pyridine reacting with 4-substituted... 

Chlorinations of nuclear and extranuclear hydroxyl groups by thionyl chloride have been described in the following piperazines l,4-diformyl-2,3,5,6-tetrahydroxy (thionyl chloride and pyridine at reflux) (895), 2,3,5,6-tetrahydroxy-l,4-bis-(methanesulfonyl) (895), 2-hydroxymethyl-l,4-di( )methyl (thionyl chloride in carbon tetrachloride at 70°) (1649), 2-(2 -hydroxyethyl) (1671), and l-benzyl-4-(2 -hydroxyethyl) (1723). Treatment of 2-hydroxymethyl-1,4-ditosylpiperazine with dibromotriphenylphosphorane gave 2-bromomethyl-l,4-ditosylpiperazine (1650). 

Many macrocyclic SBs have been prepared by condensation of different dicarbonyl precursors (head units (55), see Scheme 16) such as 2,6-diformylpyridine (56, R = H, 56a), 2,6-diacetylpyridine (56, R = CH3, 56b), 2,6-diformyl-4-Z-phenol (57, Z = C1- 57a, CH3-, 57b), 2,6-diacetyl-4-Z-phenol (57, Z = C1—, 57c, Z = CH3, 57d) thiophene-2,5-dicarbaldehyde (58), furan-2,5-dicarbalde-hyde (59), pyrrole-2,5-dicarbaldehyde (60), 2,6-diformyl-4Z-thiophenol (61, Z = CH3, 61a Z Bu1, 61b) or /3-triketones (62) with a wide range of different diamines (lateral chains). The majority of SB macrocycles are symmetrical and contain either phenol or pyridine as head units. Asymmetrical SB macrocycles have also been prepared. The SB macrocycles are designated [1 + 1] and [2 + 2] depending on the number of head and lateral units present (see Scheme 17). With certain precursors (i.e., 2,6-diacetylpyridine and l,3-diamino-2-hydroxypropane) [3 + 3] and [4 + 4] macrocyclic complexes have also been synthesized.177-179 The [2 + 3] condensation products have also... 

The O.O -dimethyl-Xanthocillin 28 was prepared from its N, N -diformyl-diamine 27. This was dehydrated by phenyl-sulfonyl-chloride in the presence of pyridine. The procedure was published in Pharmazie [53] in East Germany in 1956, but was not available to Western countries. The method can be used particularly if isocyano-polymers are formed [54]. Two years later, Hertler and Corey [55] reported a similar conversion of a formyla-mino-steroid into its isocyano-derivative. 

Clezy s modification of the MacDonald synthesis using a 5,5 -diformyl-pyrro-ketone instead of a diformyl-pyrromethane has been extended to the synthesis of the a-oxy-derivative of mesoporphyrin IX and to the y-oxy-derivative of protoporphyrin IX (Scheme 3). The iron complex of the latter undergoes oxidative ring opening in pyridine solution to form biliverdin IX-y (25), the parent compound of a series of three green pigments found in certain types of butterflies and caterpillars this provides a model for their probable mode of biosynthesis. 

ICC1063) and di- 318 (02JCS(D)441) azine-coordinated nickel complexes can be prepared from pyridine-containing aldimines of 2,6-diformyl-4-methylphenol. A nickel cationic complex of a 2,6-bis-azomethine derivative contains two coordinated pyridine N-substituents 319 (M = Ni, R = H, R = Me, = MeOH) (96T3521). Zinc chelate 319 (M = Zn, R = R = Me, no L) has a similar structure (02IC6426). Tetranuclear manganese poly-chelate contains two coordinated pyridine... 

The 2-formyl-pyridine-based PPEI (79), a bidentate, and the 2,6-diformyl-P3rridine-based BDFEPI (80), a potentially terdentate, ligands bear a-methyl-benzylamine and amino-1,2-diphenylethane chiral moieties, respectively... 

A review has covered mainly the preparation of aldehydes from carbon monoxide by electrophilic aromatic substimtions involving superacids. In HF-SbFs, some polynuclear aromatic compounds are diformylated. When pyridine-3-carboxaldehyde is compared with benzaldehyde in acid-catalysed condensation reactions with benzene and substituted benzenes to form diaryl-3-pyridylmethanes, it is found to be... 

Ammonia bubbled through a soln. of 350 mg. of the startg. diformyl compound in methanol for 5 min. 230 mg. pyridine derivative. 

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