水杨醛合成技术的新进展

综述了合成水杨醛的甲酰化法、氯化水解法和还原法的最新研究与发展 趋势。简要总结了Sn 和Mg离子催化苯酚定向甲酰化制备水杨醛的反应机理及过程。     

Reactions of Tertiary Allylic Amines and Dichlorocarbenes

In this article, a study on reactions of tertiary allylic amines and dichlorocarbenes had been described. Tertiary allylic amines could result from an interesting de-N-allylation/formylation reaction under the treatment of dichlorocarbenes. Notably, amines containing steric substituents or electron-deficient aromatic substituents on the nitrogen will go through cyclopropanations of the carbon–carbon double bond.     

Transition-Metal-Catalyzed Utilization of Methanol as a C1 Source in Organic Synthesis

Methanol is used as a common solvent, cost-effective reagent, and sustainable feedstock for value-added chemicals, pharmaceuticals, and materials. Among the various applications, the utilization of methanol as a C₁ source for the formation of carbon–carbon, carbon–nitrogen, and carbon–oxygen bonds continues to be important in organic synthesis and drug discovery. In particular, the synthesis of C-, N-, and O-methylated products is of central interest because these motifs are found in a large number of natural products as well as fine and bulk chemicals. In this Minireview, we summarize the utilization of methanol as a C₁ source in methylation, methoxylation, formylation, methoxycarbonylation, and oxidative methyl ester formation reactions.     

二烷基二茂铁甲酰化反应的研究

甲酰基二茂铁是一种极为重要的二茂铁衍生物。以它为中间体 ,经缩合、还原和氧化等反应 [1～ 3] ,可得到许多其它的二茂铁化合物。在甲酰基二茂铁分子中引入烷基后 ,其性质在两个方面会发生显著变化。一是含碳量增加 ,导致其衍生物在有机溶剂中的溶解度增加 ;另一是化合物的物态发生了很大变化 ,固态会变为液态 ,高熔点物会变为低熔点物 ,为合成液态或低熔点二茂铁化合物提供了丰富的中间体。有关二烷基二茂铁甲酰化反应的报道甚少[4 ] ,更未见系统地研究过多种不同烷基的引入对甲酰化反应的影响。为此我们研究了 6种二烷基二茂铁的 Vilsme…     

Simple and efficient synthesis of various dibenzofuran carbaldehydes

We herein report simple and efficient methods for the synthesis of various formyl derivatives of dibenzofuran. The aldehydes reported are prepared in at most three steps and in yields greater than 60% from commercially available dibenzofuran, with one exception where isomers must be separated. The protocols described involve either formylation of previously functionalized dibenzofuran derivatives or the initial introduction of the formyl group and subsequent further functionalization under standard reaction conditions as described. We have also reported an efficient and simple method for the synthesis of key methoxydibenzofurans in high yield (65% overall for two steps).     

Computational study of the catalytic synthesis of 5‐nitro‐1,2,4‐triazol‐3‐one

In this study, 5‐nitro‐1,2,4‐triazol‐3‐one (NTO) was theoretically synthesized from urea via chlorination followed by amination, formylation, and nitration under aqueous and gaseous environments based on experience of experimental methods, and metal chlorides and metal oxides were used as catalysts to promote reaction. Reaction routes closely related to experimental processes were successfully constructed, and the corresponding energy barriers were estimated for each elementary reaction. Reaction conditions distinct from those reported in the literature (including the adoption of aluminum chloride, ferric chloride, aluminum oxide, ferrous oxide, and chromium oxide catalysts, the use of nitric acid and dinitrogen pentoxide as nitration agents, and adjustment of the reaction temperature) were used in corresponding reaction systems, and the modeling results suggested that ferric chloride is a good catalyst for the chlorination reaction, ferrous oxide is suitable for catalyzing amination, formylation, and nitration, and nitric acid is the better agent for nitration. Estimates of the comparable energy barriers for each reaction stage were considered to imply more feasible pathways for NTO synthesis. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Synthesis of Formyl Derivatives of 2-Hetarylimidazoles Annelated with Naphthalene and Phenanthrene Rings

The formylation reaction of a series of 2-hetarylimidazoles, annelated by naphthalene and phenanthrene rings, using hexamethylenetetramine in PPA and the Vilsmeier reagent has been studied. The furyl and thienyl derivatives form principally the 5-formyl-substituted and the pyrrolylimidazoles were found to give a mixture of the - and -formyl derivatives.     

Synthesis of formyl-thienylpyrroles: versatile building blocks for NLO materials

Several formyl-substituted 1-alkyl(aryl)-2-(2′-thienyl)pyrroles 3-7 were synthesized by functionalization of the pyrrole or thiophene ring of thienylpyrroles 2 using different methods: Vilsmeier formylation or metalation followed by reaction with DMF.     

Convenient Synthesis of 6-Bromo-1,2,3,4-tetrahydroisoquinoline and 3-Methoxy-1,2,3,4-tetrahydro-[2,7]-naphthyridine via Reductive Amination of Schiff's Bases

Synthesis of 7-bromo-1,2,3,4-tetrahydroisoquinoline and 6-methoxy-1,2,3,4-tetrahydro-[2,7]-naphthyridine via lithiation of 2-methylarylidene-tert-butylamines, followed by formylation, reductive amination in one-pot, and removal of the tert-butyl group from the nitrogen, is described.     

1-Butyl-3-methylimidazolium Hydrogen Sulfate [bmim]HSO4: An Efficient Reusable Acidic Ionic Liquid for the Formylation of Alcohols

1-Butyl-3-methylimidazolium hydrogen sulfate [bmim]HSO4 as an acidic ionic liquid was prepared and used as a catalyst for the formylation of alcohols with ethyl formate at room temperature with good to excellent yields. A good selectivity was observed for the formylation of primary alcohols in the presence of tertiary alcohols.     

Vilsmeier—Haack reaction of methyl lambertianate and non-sensitized photocyclization of the resulting product

Vilsmeier—Haack formylation of methyl lambertianate results in its 16-formyl derivative as the predominant product, which readily enters the intramolecular reaction of photochemical [2+2]-cycloaddition in the absence of a sensitizer.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2514–2517, December, 1995.     

A novel method for the formylation of Grignard reagent

A facile and efficient method for the formylation of Grignard reagent was reported, and a new approach for the preparation of aldehydes from Grignard reagent and benzimida-zolium salts was provided.     

Indole Derivatives. 141. Synthesis and Investigation of New 2-Arylindoles

2-(Diphenylmethan-4-yl)- and 2-(dibenzyl-4-yl)indoles have been synthesized by the Fischer reaction. Reactions carried out included azo coupling, formylation, and nitrosation. The corresponding 3-substituted derivatives were obtained.     

Heterocyclic analogs of pleiadiene. 75. Formylation of perimidines and 2,2-dimethyl-2,3-dihydroperimidine under vilsmeier conditions

The formylation of perimidine, its 2-and 3-methyl derivatives, and 2,2-dimethyl-2,3-dihydroperimidine has been studied under the conditions of the Vilsmeier reaction. In the last case recyclization occurs. The characteristics of the ¹H NMR spectra of the aldehydes obtained are discussed. For part 74, see [1]. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, 104–112, January, 2006.     

Metal-free N-formylation of 2-aminophenols using dimethylformamide and CSA

DMF has been proved to be an efficient formylation reagent for 2-aminophenols in the presence of (±) camphorsulfonic acid (CSA) in this work. CSA works as an acid catalyst and a neutralizer of dimethyl amine which is kicked off from DMF. Both electron-withdrawing and electron-donating groups are tolerated. More importantly, the product could be achieved in gram scale with the possibility of further diversifying into biologically interesting structures.     

predForm-Site: Formylation site prediction by incorporating multiple features and resolving data imbalance

Formylation is one of the newly discovered post-translational modifications in lysine residue which is responsible for different kinds of diseases. In this work, a novel predictor, named predForm-Site, has been developed to predict formylation sites with higher accuracy. We have integrated multiple sequence features for developing a more informative representation of formylation sites. Moreover, decision function of the underlying classifier have been optimized on skewed formylation dataset during prediction model training for prediction quality improvement. On the dataset used by LFPred and Formator predictor, predForm-Site achieved 99.5% sensitivity, 99.8% specificity and 99.8% overall accuracy with AUC of 0.999 in the jackknife test. In the independent test, it has also achieved more than 97% sensitivity and 99% specificity. Similarly, in benchmarking with recent method CKSAAP_FormSite, the proposed predictor significantly outperformed in all the measures, particularly sensitivity by around 20%, specificity by nearly 30% and overall accuracy by more than 22%. These experimental results show that the proposed predForm-Site can be used as a complementary tool for the fast exploration of formylation sites. For convenience of the scientific community, predForm-Site has been deployed as an online tool, accessible at http://103.99.176.239:8080/predForm-Site.     

An Efficient and General Method for Formylation of Aryl Bromides with CO2 and Poly(methylhydrosiloxane)

The formylation of aryl halides with CO₂ to generate aryl aldehydes is challenging. Herein, we report a novel synthesis of aryl aldehydes by formylation of aryl bromides with CO₂ and a waste silane, poly(methylhydrosiloxane) (PMHS). It has been discovered that a simple combination of 1,3‐bis(diphenyphosphino)propane (DPPP)‐chelated Pd catalyst, Pd(DPPP)Cl₂, with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) is able to effectively catalyze the reaction, leading to aryl aldehydes in moderate to excellent yields, and without any by‐products in most cases. Moreover, this route could be extended to the formylation of aryl iodides with high efficiency. This approach is simple, less costly, and environmentally friendly, and also widens the applications of CO₂ to form value‐added chemicals by the construction of new C?C bonds.     

Formylation of pyrrolo-[1,2-<Emphasis Type="Italic">a</Emphasis>]pyrazines

The formylation of pyrrolo[1,2-a]pyrazines containing alkyl, aryl, or hetaryl substituents in positions 1 and 6 of the heterocycle has been studied. It has been shown that formylation of 1-phenyl-and 1-(2 thienyl)pyrrolo[1,2-a]pyrazine occurs selectively at the α-position of the pyrrole ring. In all of the remaining examples the reaction course depends on substituent, reagent ratio, and reaction time. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 88–93, January, 2008.     

Hydrophosphination of CO2 and Subsequent Formate Transfer in the 1,3,2‐Diazaphospholene‐Catalyzed N‐Formylation of Amines

Hydrophosphination of CO₂ with 1,3,2‐Diazaphospholene (NHP‐H; 1 ) afforded phosphorus formate (NHP‐OCOH; 2 ) through the formation of a bond between the electrophilic phosphorus atom in 1 and the oxygen atom from CO₂, along with hydride transfer to the carbon atom of CO₂. Transfer of the formate from 2 to Ph₂SiH₂ produced Ph₂Si(OCHO)₂ ( 3 ) in a reaction that could be carried out in a catalytic manner by using 5 mol % of 1 . These elementary reactions were applied to the metal‐free catalytic N‐formylation of amine derivatives with CO₂ in one pot under ambient conditions.     

Effective Formylation of Amines with Carbon Dioxide and Diphenylsilane Catalyzed by Chelating bis(tzNHC) Rhodium Complexes

The reductive formylation of amines using CO₂ and hydrosilanes is an attractive method for incorporating CO₂ into valuable organic compounds. However, previous systems required either high catalyst loadings or high temperatures to achieve high efficiency, and the substrate scope was mostly limited to simple amines. To address these problems, a series of alkyl bridged chelating bis(NHC) rhodium complexes (NHC=N‐heterocyclic carbene) have been synthesized and applied to the reductive formylation of amines using CO₂ and Ph₂SiH₂. A rhodium‐based bis(tzNHC) complex (tz=1,2,3‐triazol‐5‐ylidene) was identified to be highly effective at a low catalyst loading and ambient temperature, and a wide substrate scope, including amines with reducible functional groups, were compatible.