Synthesis of dialdehydes of tetrahydrofuran series

Summary The hydrogenation of the diacetals of furan dialdehydes gave the previously unknown diacetals of tetrahydrofuran dialdehydes, which by hydrolysis were converted to the previously unknown dialdehydes of the tetrahydrofuran series.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 380–381, February, 1965     

Analysis of the component aldehyde and alcohols in borohydride-reduced dialdehydes from hexosamine derivatives

Unlike the dialdehydes formed from neutral monosaccharide residues, the dialdehydes from hexosamine residues are resistant to acidified ethanethiol, leaving the hemiacetal bond intact. However, the borohydride-reduced dialdehydes are readily split into the component aldehyde and alcohols; gas Chromatographic analysis of their derivatives is useful for structural studies of hexosamine-containing carbohydrates. Investigation by these sequential derivatization reactions indicated that anomeric methyl 2-acetamido-2-deoxy-$\text{d}$-glucopyranosides were oxidized in normal Malapradian fashion, whereas 2-acetamido-2-deoxy-$\text{d}$-glucose was over-oxidized. The rate of oxidation of 2-acetamido-D-glucitol was very rapid; the oxidation product can also be analyzed by the direct dithioacetal method (mercaptalation followed by trimethylsilylation).     

Formation of Heterocyclic and Polycyclic Compounds from Amino Alcohols and Dialdehydes

Amino alcohols typically react with aldehydes to produce oxazolidines. It was hypothesized that the condensation of several commercially available amino alcohols with dialdehydes would produce a series of bicyclic oxazolidines containing two secondary amines. However, there were remarkable differences in the type of products formed depending on the structure of the dicarbonyl compounds and the reaction conditions. When linear aliphatic dialdehydes such as glyoxal were used, the expected bis‐oxazolidines were not produced; instead, polycyclic structures or oxazines were formed. However, when cyclic dialdehydes such as 1,3/1,4 cyclohexane dicarboxaldehyde were used, they resulted in products bearing the desired oxazolidine moieties.     

Microwave assisted cyclocondensation of dialdehydes with chiral diamines forming calixsalen type macrocycles

Microwave irradiation of various dialdehydes and chiral diamines afforded chiral macrocyclic imines in moderate to good yields. Linked dialdehydes predominantly form [2+2] macrocycles whereas dialdehydes without linkers yield [3+3] macrocycles. This is the first report of template-free synthesis of calixsalen-type macrocycles formed in shorter reaction times under microwave conditions. In all the reactions, the salts of chiral diamines were used in contrast to the free diamines normally employed.     

Syntheses and characterizations of oligo(azomethine ether)s derived from 2,2′-[1,4-enylenebis (methyleneoxy)]dibenzaldehyde and 2,2′-[1,2-phenylenebis (methyleneoxy)]dibenzaldehyde

The oligo(azomethine ether)s were synthesized via polycondensation of alkyl diamines with aromatic dialdehydes. Two series of dialdehydes,namely 2,2’-[l,2-phenylenebis(methyleneoxy)]dibenzaldehyde[2,2’-l,2-(PBMODB)]and 2,2’- [l,4-phenylenebis(methyleneoxy)]dibenzaldehyde[2,2’-l,4-(PBMODB)]were prepared from the condensation reactions of salicylaldehyde with o-xylenedibromide and /7-xylenedibromide,respectively.The structures of dialdehydes and oligomers were determined by FT-IR,’ H-NMR and 13C-NMR.The thermal analyses of oligomers were conducted by DSC and TG/DTA techniques,respectively.Size exclusion chromatography(SEC) technique was also used to determine molecular weights and molecular weight distributions of oligomers.Electrochemical properties of the synthesized products were investigated.     

醚链桥接芳香二醛及其缩氨硫脲的合成

一些缩氨硫脲及其衍生物对结核、麻风、风湿、疟疾、天花、真菌和某些肿瘤有一定的药理活性。缩氨硫脲的真菌活性是由于它的配位原子在生物体的新陈代谢中和真菌所需的金属离子螯合。缩氨硫脲具有与氨基酸、肽、蛋白质、酶、核糖核酸等生物配体相同的配位原子、被看作研究生物配体和痕量金属离子配位的优良模型。因为聚乙二醇醚链上的氧原子能与金属离子配位,所以在缩氨硫脲分子中连接上聚乙二醇醚链,增加缩氨硫脲分子中的配位原子种类和数目,也许能够增强螯合剂的配位能力,扩展其与金属离子的螯合围范。为此,我们将缩乙二醇二氯化物和苯环上带酰基的苯酚反应,制成化合物1_(a-h),然后再与硫代氨基脲缩合,得到醚链桥接的芳香醛缩氨硫脲2_(a-g)。它们的合成路线和主要结构如下:     

Synthesis and NMR spectroscopic analysis of 3-nitro-pyranoside, 3-nitro-septanoside and 4-nitro-septanoside derivatives by condensation of the anion of nitromethane with glycoside dialdehydes

The utility of the nitroaldol reaction for accessing 3-nitro-pyranoside, 3-nitro-septanoside or 4-nitro-septanoside derivatives, by reaction of the anion of nitromethane with glycoside dialdehydes is demonstrated. Initially, the feasibility of using unprotected glucoside dialdehydes was probed for the synthesis of the septanoside products, but this afforded pyranoside rather than septanoside targets. Subsequent studies utilised protected glycoside dialdehydes within the methodology, which allowed entry into a range of 3-nitro or 4-nitro-septanosides in good yield. NMR spectroscopic analysis allowed determination of the stereochemistry of each of the products thus afforded.     

铑(Ⅰ)/三-H_8-联萘单齿亚磷酸酯高效催化双环戊二烯氢甲酰化制备双醛（英文）

双环戊二烯(DCPD)是石脑油和燃料油裂解蒸汽的C5馏分中最重要的组分之一.DCPD经氢甲酰化反应可转化为具有广泛应用前景的三环癸烷不饱和单甲醛(TCDMA)和三环癸烷二甲醛(TCDDA),并可通过还原或胺化进一步转化为相应的醇和胺类化合物,用于农药、医药、润滑油和香料等的合成.但是,由于其分子结构中含有3,4-位和8,9-位两种不同活性的不饱和双键,因此DCPD氢甲酰化反应的产物通常非常复杂.过去数十年,研究者们为此相继开发了高转化率和高选择性的催化体系.但是反应条件相对都比较苛刻,尤其是对于双醛TCDDA的合成,通常需要较高的反应温度和反应压力以及大量的催化剂.本文以2'-联萘位置含有不同酯取代基(OCOMe,OCOPh,OCOAdamantyl和OCOPhCl)的三-H8-联萘单齿亚磷酸酯L1-L4为配体,以不同价态的金属铑前驱体为催化剂,开发了Rh催化DCPD氢甲酰化反应的新体系,并对亚磷酸酯配体、不同价态的金属铑催化剂前驱体、反应温度、反应时间、溶剂以及不同的底物和催化剂的S/C摩尔比对DCPD转化率和TCDDA选择性的影响进行了深入的研究.结果表明,当以金属铑前驱体Rh(acac)(CO)_2和配体L4-OCOPhCl为催化体系时,在DCPD氢甲酰化反应中表现出很高的活性,尤其是当S/C=4000时,TON值达到3286,并且该催化体系对于双醛TCDDA具有良好的选择性.值得注意的是,在相对温和的条件(6 MPa,120℃)下,Rh(Ⅰ)催化剂与氯苯酯基取代的三-H_8-联萘单齿亚磷酸酯所形成的配合物在催化DCPD的氢甲酰化反应中,DCPD的转化率达到99.9%,而双醛TCDDA的选择性达到98.7%.此外,我们采用L4-OCOPhCl作为模型单齿磷酸配体,在溶液中通过NMR对可能形成的Rh(Ⅰ)/亚磷酸酯催化物种进行了深入的考察.~(13)P NMR谱图表明,在DCPD的氢甲酰化反应中,催化物种[Rh(acac)(CO)(L4-OCOPhCl)]比[Rh(acac)(CO)(L2-OCOPh)]具有更好的稳定性,而且只有体积较大的配体L4-OCOPhCl才能与铑前驱体Rh(acac)(CO)_2进行很好的配位.     

Optically active macrocyclic hexaazapyridinophanes decorated at the periphery: synthesis and applications in the NMR enantiodiscrimination of carboxylic acids

A family of pyridine based dialdehydes has been efficiently prepared starting from chelidamic acid by chemical modification of its 4-hydroxyl group. The condensation of these dialdehydes with commercially available (1R,2R)-(−)-cyclohexane-1,2-diamine in the presence of Ba²⁺ template led, after the in situ reduction, to the synthesis of a family of enantiopure hexaazapyridinophanes substituted at the periphery. These new receptors have been used as chiral shift agents towards different carboxylic acids. Good splitting of the carboxylic acid NMR signals (up to ΔΔδ=0.13 ppm) were observed using substoichiometrical amount of the receptor.     

N?O Bond as a Glycosidic‐Bond Surrogate: Synthetic Studies Toward Polyhydroxylated N‐Alkoxypiperidines

A series of novel polyhydroxylated N‐alkoxypiperidines has been synthesized by ring‐closing double reductive amination (DRA) of highly functionalized 1,5‐dialdehydes with various hydroxylamines. The required saccharide‐based dialdehydes were prepared efficiently from sodium cyclopentadienylide in seven steps. A two‐step protocol has been developed for the DRA; it led, after deprotection, to isofagomine, 3‐deoxyisofagomine, and numerous other N‐alkoxy analogues. The barrier to inversion in these polyhydroxylated N‐alkoxypiperidine derivatives was found by variable‐temperature NMR methods to be approximately 15 kcal mol^?1. With the exception of N‐hydroxyisofagomine itself, none of the compounds prepared showed significant inhibitory activity against sweet almond β‐glucosidase.     

Hydrogen‐Bond‐Driven Controlled Molecular Marriage in Covalent Cages

A supramolecular approach that uses hydrogen‐bonding interaction as a driving force to accomplish exceptional self‐sorting in the formation of imine‐based covalent organic cages is discussed. Utilizing the dynamic covalent chemistry approach from three geometrically similar dialdehydes ( A , B , and D ) and the flexible triamine tris(2‐aminoethyl)amine ( X ), three new [3+2] self‐assembled nanoscopic organic cages have been synthesized and fully characterized by various techniques. When a complex mixture of the dialdehydes and triamine X was subjected to reaction, it was found that only dialdehyde B (which has OH groups for H‐bonding) reacted to form the corresponding cage B₃X₂ selectively. Surprisingly, the same reaction in the absence of aldehyde B yielded a mixture of products. Theoretical and experimental investigations are in complete agreement that the presence of the hydroxyl moiety adjacent to the aldehyde functionality in B is responsible for the selective formation of cage B₃X₂ from a complex reaction mixture. This spectacular selection was further analyzed by transforming a nonpreferred (non‐hydroxy) cage into a preferred (hydroxy) cage B₃X₂ by treating the former with aldehyde B . The role of the H‐bond in partner selection in a mixture of two dialdehydes and two amines has also been established. Moreover, an example of unconventional imine bond metathesis in organic cage‐to‐cage transformation is reported.     

New Protocol for Masking and Unmasking Vicinal Hydroxyl and Formyl Groups in 6-Hydroxyarene-1,3-dicarboxaldehydes

A simple and efficient protocol is revealed for the masking and unmasking of an α-hydroxyl benzaldedyde group in aromatic dialdehydes by forming keto-enamine Schiff bases and subsequent unmasking using NaN₃/DMF.     

Periodate oxidation analysis of carbohydrates: Part IX. Evaluation of the use of pyridine as reaction solvent for oxidation of water-insoluble carbohydrate materials

Oxidation of methyl glycopyranosides with periodic acid in pyridine was studied by analysis of the reaction products by the dithioacetal method. Both C₂—C₃ and C₃—C₄ bonds were cleaved yielding three types of dialdehydes;secondary attack of these dialdehydes by periodic acid did not occur. Oxidation in aqueous pyridine proceeded in normal Malapradian fashion, but more slowly than for oxidation in water. Molar proportions of aldehydes were theoretical, when methyl glycosides were oxidized with periodic acid in a 1:1 ($\text{v}\text{v}$) mixture of pyridine and water. The structures of carbohydrate moieties in a few saponins and glycolipids were confirmed by analysis of the oxidation products obtained under similar conditions.     

Simultaneous construction of a polyether backbone and a variety of keto side chains by three‐component polycondensation: An improved method for the use of a variety of silyl enol ethers

For the synthesis of polyethers with a variety of keto side chains in a one‐step reaction, the three‐component polycondensation of dialdehydes, diol disilyl ethers, and silyl enol ethers of ketones was investigated. The method of monomer addition strongly affected the molecular weight of polymers and was optimized to yield high molecular weight polymers by model reactions. A variety of dialdehydes, diol disilyl ethers, and silyl enol ethers were polymerized in the presence of a catalytic amount of triphenylmethyl (trityl) perchlorate in CH₂Cl₂ at −78 °C according to the method of monomer addition. This polymer synthesis was unusual in that it concurrently constructed both the polyether backbone and the keto side chains from three starting compounds. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 179–188, 2000     

Preparation of azulene-derived fulvenedialdehydes and their application to the synthesis of stable adj-dicarbaporphyrinoids

A "2 + 2" strategy for synthesizing adj-dicarbaporphyrinoid systems has been developed. In a model study, an azulenylmethylpyrrole dialdehyde was condensed with a dipyrrylmethane in the presence of HCl, followed by oxidation with ferric chloride, to give a modest yield of an azuliporphyrin. Fulvene aldehydes were prepared by reacting an indene-derived enamine with azulene aldehydes in the presence of Bu(2)BOTf, and azulene dialdehydes similarly reacted to give fulvene dialdehydes. The dialdehydes were condensed with dipyrrylmethanes in TFA/dichloromethane to afford good to excellent yields of dicarbaporphyrinoids with adjacent indene and azulene subunits. These 22-carbaazuliporphyrins exhibited significant diatropic character, and this property was magnified upon protonation. These characteristics are attributed to tropylium-containing resonance contributors that possess 18π electron delocalization pathways. Protonation studies demonstrated that C-protonation readily occurred at the interior indene carbon, but deuterium exchange also occurred at the internal azulene CH as well as at the meso-positions with TFA-d. Reaction of a carbaazuliporphyrin with silver(I) acetate in methanol or ethanol solutions also gave unusual nonaromatic dialkoxy derivatives.     

Synthesis,spectroscopy and metallation of mixed carbaporphyrinoid systems

Modified tripyrranes incorporating furan and thiophene rings were found to condense with benzene, pyridine and indene dialdehydes to give a series of novel porphyrin analogues, including thia- and oxa-carbaporphyrins; the latter readily forms nickel(II) and palladium(II) organometallic complexes.     

A new synthesis of chlorins

A new synthesis of chlorins has been developed, based upon the acid-catalyzed condensation of dialdehydes AB with dipyrromethanes CD.     

聚乙二醇醚链桥接缩氨脲和缩甲硫基氨基硫脲的合成

一些缩氨硫脲对结核,麻风、风湿、疟疾、天花、真菌和肿瘤有一定的药理活性。考虑到变更缩氨硫脲的硫代羰基上的硫原子为氧原子,或者变更其端基有可能改变其药理活性,在前文基础上,本文继续报道聚乙二醇醚链桥接缩氨硫脲和缩甲硫基氨基硫脲的合成。以缩二醇二氯化物合产物与甲酰基苯酚的缩合产物再与相应的氨基脲和甲硫基氨基硫脲反应,制得化合物1-8。     

The Synthesis of Dialdehyde from Sodium Hydrogen Telluride with 1,1'''',3,3''''-Tetramethyl-2,2''''-bis-benzimidazolium Salt

Dialdehydes are important chemical industrial materials. An efficient preparation method of dialdehydes has been interested. We have reported two novel synthetic methods of dialdehyde via the addition-hydrolysis reaction of benzimidazolium salt with bis-Grignard reagent1 and the reduction-hydrolysis reaction of diimidazoline2. Sodium hydrogen telluride has been shown to be a convenient reagent for the reduction of unsaturated nitro-compounds to saturated ones3. The reduction of N-methylpy…     

Direct observation by H NMR of 4,5-benzoxepin-2,3-oxide and its surprisingly rapid ring-opening rearrangement to 1H-2-benzopyran-1-carboxaldehyde

The first unambiguous observation of an oxepin-2,3-oxide is reported. Between 5 and 10 °C it rearranges rapidly to its isomer 1H-2-benzopyran-1-carboxaldehyde. In contrast, 2,3-oxides of monocyclic oxepins rearrange to stable, ring-opened dialdehydes or diketones.