Synthesis, Chemistry, and Applications of Heterocyclic Cage Compounds (V)

The synthesis and chemistry of polycyclic of cage compounds have attracted considerable attention in recent years. The vast majority of the work reported in this area has dealt with carbocylic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.1 As part of a program that involves the synthesis, chemistry, and application of heterocyclic cage compounds, we report here the synthesis of new thia-oxa-cage compounds and the chemical nature of these thia-cages.     

Synthesis,Chemistry and Applications of Heterocyclic Cage Compounds (V)

The synthesis and chemistry of polycyclic cage compounds have attracted considerable attention in recent years.¹ The vast majority of the work reported in this area has dealt with caybocyclic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we have accomplished the synthesis of a series of oxa-cage compounds and performed the chemical transformations of these oxa-cage compounds.² As part of a program that involves the synthesis,chemistry and applications of heterocyclic cage compounds we report here the synthesis of heterocyclic cage compounds 1-12. We also wish to report the applications of compounds 7-12 on the π-facial selectivities. Studies on the cation-binding properties of compounds 1 and 2 and other oxa-cages are undertaken.     

Additions to non-activated alkenes: Recent advances

Non-activated olefins represent one of the most explored platform in organic synthesis affording new and useful compounds with several biological applications, among others. The typical reactivity of these compounds is the addition-type reactions. A plethora of transformations and studies were reported in the literature by many research groups. The focus of this review is to organize and describe the most recent synthetic transformations of non-activated alkenes in organic synthesis. Therefore, it is divided into five sections corresponding to each type of the products obtained: synthesis of fluoro-, chloro- and bromo-compounds; synthesis of alkyl/vinyl/aryl/heteroaryl compounds; synthesis of phospho/sulfur/silyl/cyano-compounds; synthesis of amine/amide/oxygenated compounds and synthesis of other functionalized compounds.     

光学活性化合物的工业合成

本文介绍了光学活性化合物研究现状及发展趋势。并从技术和经济角度论述了工业合成光学活性化合物的可能性     

Toward high-throughput synthesis of complex natural product-like compounds in the genomics and proteomics age

In the age of high-throughput biology, novel genes and proteins are emerging quickly. The need for developing organic synthesis-derived methods that allow rapid access to polyfunctional, complex natural product-like compounds is growing constantly, largely because these small-molecule-based compounds serve as smart, powerful tools both in understanding the roles and functions of emerging biological targets and in validating their biological responses. Developing asymmetric synthesis-derived organic reactions on solid phase allows the synthesis of complex natural product-like compounds in a high-throughput manner. Solid phase organic synthesis is now commonly utilized in the library synthesis of rather simple compounds (i.e., compounds with no multiple stereogenic centers). With few exceptions, the synthesis of complex natural product-like derivatives is still in its infancy. Some recent efforts made in this area indicate opportunities yet to be explored.     

Thermal Analysis of Pigments Based on CeO2

The synthesis of new compounds based on CeO₂ is investigated in our laboratory. The main attention is directed to the preparation of these compounds which can be used as pigments for colouring of ceramic glazes. The synthesis of these compounds is based on high-temperature calcination of starting oxides. The optimum conditions for the syntheses of compounds have been estimated and the pigments prepared have been evaluated from the standpoint of their structure. This revised version was published online in July 2006 with corrections to the Cover Date.     

meso Compounds: Stepchildren or Favored Children of Stereoselective Synthesis?

After more than a quarter of a century of development, the methodology of stereoselective synthesis appears to be fully matured. In line with this, the potential that meso compounds offer in stereoselective synthesis is clearly recognized. The use of meso compounds in synthesis is, however, in no way commensurate with this potential, because, ironically, the synthesis of meso compounds in the first place is a problem of stereoselective synthesis. Present-day methodology does not provide many useful solutions to this problem. This Review therefore addresses the strategies available for the synthesis of more elaborate meso compounds whose stereogenic centers have a distance >1,4 between them. meso Compounds with more than four stereogenic centers are also considered. The criteria used in choosing from several strategies in the synthesis of such compounds are discussed.     

The 4-tert-butylphenyl group as a simple tag for solution phase synthesis

A solution phase synthesis strategy was investigated using 4-tert-butylphenyl group as the tag and a beta-cyclodextrin column as the affinity chromatographic support for the isolation of compounds containing the tag. It was found that compounds containing the tag have significantly longer retention times on the beta-cyclodextrin column than those compounds that do not have such a tag. The tag is chemically inert and can be introduced onto and removed from target compounds readily. This solution phase synthesis method was applied to the synthesis of some simple amino acid derivatives.     

Ultrasound irradiation in heterocycle synthesis: An overview

The synthesis of heterocyclic compounds has been a hot topic for several decades. Synthetic organic chemists are always in search of new methodologies which are greener for the synthesis of heterocyclic compounds. The ultrasound-assisted reactions have contributed much to this field. This review focuses on the impact of sonochemistry in the synthesis of heterocyclic compounds and covers the literature from 2009 to 2020.     

Diels-Alder Reactions of 6-Hydroxy-2H-pyran-3(6H)-ones with Cyclopentadiene and Its Application for the Synthesis of New Skeletal Oxa-Cage Compounds

The 2(5H)-furanone and 3(6H)-pyranone structures are frequently found in natural products, which have a broad range of biological activities. In addition, furanones and pyranones have served as versatile intermediates in the synthesis of a variety of products. 1 Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.2 As part of a program that involves the synthesis, chemistry, and applications of heterocyclic cage compounds, we report here the Diels-Alder reactions of 6-hydroxy2H-pyran-3(6H)-ones 1 and 2 with cyclopentadiene and the application of the cycloadducts for the synthesis of oxa-cage compounds 3-6 with new skeleton. Compound 6 is a potential new chiral amino-alcohol.     

Computer-assisted reaction prediction and synthesis design

The design of organic syntheses requires deep insight into chemical reactivity. Methods have been developed to calculate important electronic and energy effects and use them for the modelling of reaction mechanisms. The approach is illustrated by the haloform reaction. The procedures have been incorporated into different versions of the EROS system. A study of the synthesis of fredericamycin illustrates the use of these EROS procedures in synthesis design and reaction prediction. Recent work on synthesis design for aromatic compounds is highlighted and new definitions of the similarity of chemical compounds are discussed.     

Cobalt-catalyzed one-pot three-component coupling route to beta-acetamido carbonyl compounds: a general synthetic protocol for gamma-lactams

An efficient improved procedure for the synthesis of beta-acetamido carbonyl compounds is developed by a cobalt(II) chloride-catalyzed three-component coupling protocol. The procedure is also amenable to the synthesis of gamma-lactams by a three-component coupling reaction with use of 2-carbomethoxybenzaldehyde. The beta-acetamido carbonyl compounds derived from 2-carbomethoxybenzaldehyde are useful intermediates as they can be transformed to the corresponding gamma-lactams on treatment with base.     

酰肼类化合物的羰基化制备及其在智能材料合成中的应用

酰肼类化合物在农药、医药等领域被广泛应用,其合成方法的研究备受关注.卤代物和有机肼(或单酰肼)的羰基化反应是制备酰肼类化合物的重要合成路线之一.在由羰基化反应制备酰肼类化合物的过程中,除以CO气体作为典型、廉价易得的羰基源外,CO2、DMC(碳酸二甲酯)、固体羰基配合物等都可以作为替代CO气体的潜在羰基源.我们着重介绍...     

Part 4. Fused pyrimidines. Annelation using formamide to synthesize 2,4-disubstituted-pyrimido[4,5-d]pyrimidines

A one-step synthesis of 2,4-disubstituted-pyrimido[4,5-d]pyrimidines has been investigated. Cyclization of 6-amino-2,4-disubstituted-pyrimidines with formamide as solvent and reagent affords the title compounds in 50-70% yield. Strongly electron-donating groups are required. Based on model compounds, a pathway for the cyclization is suggested. The method is an improvement on previous methods of synthesis, albeit a limited one.     

Azoxy Compounds—From Synthesis to Reagents for Azoxy Group Transfer Reactions

The azoxy functional group is an important structural motif and represents the formally oxidized counterpart of the azo group. Azoxy compounds find numerous applications ranging from pharmaceuticals to functional materials, yet their synthesis remains underdeveloped with a main focus on the formation symmetric azoxy compounds. To overcome challenges in the synthesis of such unsymmetric azoxy compounds, we designed a process employing readily accessible nitroso compounds and iminoiodinanes. This method builds on the use of visible light irradiation to generate a triplet nitrene from iminoiodinanes, which is trapped by nitroso arenes to give access to sulfonyl-protected azoxy compounds with a good substrate scope and functional group tolerance. We further describe two applications of these sulfonyl-protected azoxy compounds as radical precursors in synthesis, where the whole azoxy group can be transferred and employed in C(sp³)−H functionalization of ethers or 1,2-difunctionalization of vinyl ethers. All of the reactions occurred at room temperature under visible light irradiation without the addition of any photoredox catalysts and additives. Control experiments, mechanism investigations, and DFT studies well explained the observed reactivity.     

The combinatorial synthesis of organophosphorus compounds

The primary literature concerning the combinatorial synthesis of organophosphorus compounds is reviewed and discussed. The subject matter is divided into three main sections describing the solid phase, solution phase and solvent-free synthesis of phosphorus containing organic molecules. The review covers the synthesis of compounds in which the final products contain phosphorus-carbon bonds, primarily phosphonates, phosphinates, phosphine oxides and phosphines.     

Enantioselective Strategies for The Synthesis of N−N Atropisomers

Axially chiral compounds have been always considered a laboratory curiosity with rare prospects of being applied in asymmetric synthesis. Things have changed very quickly in the last twenty years when it was understood the important role and the enormous impact that these compounds have in medicinal, biological and material chemistry. The asymmetric synthesis of atropisomers became a rapidly expanding field and recent reports on the development of N−N atropisomers strongly prove how this research field is a hot topic open to new challenges and frontiers of asymmetric synthesis. This review focuses on the recent advances in the enantioselective synthesis of N−N atropisomers highlighting the strategies and breakthroughs to obtain this novel and stimulating atropisomeric framework.     

2-碘酰基苯甲酸在有机合成中的研究与应用

高价有机碘化合物的反应性质与过渡金属相似,其参与的反应具有反应条件较温和、选择性好、产率高及环境友好等优点,因而近年来关于高价有机碘试剂的研究受到广泛关注,在有机合成领域中获得了较多应用.综述了近年来高价有机碘试剂2-碘酰基苯基酸(IBX)在有机合成中的研究及应用,包括IBX在氧化羟基、含氮化合物和含硫化合物,在制备α...     

Polymer-supported N-derivatized, o-linked hydroxylamine for concurrent solid-phase synthesis of diverse N-alkyl and N-H hydroxamates

We describe parallel/combinatorial, solid-phase, supported synthesis of diverse hydroxamates using a common intermediate, an N-derivatized, O-linked hydroxylamine. The method allows the concurrent synthesis of both N-alkyl and N-H hydroxamates and is compatible with a wide range of chemical transformations. The synthesis of NH hydroxamates includes protection of the nitrogen with a 2,4-dimethoxybenzyl group at the stage of polymer-supported benzyloxyamine. The protecting group eliminates side reactions caused by the presence of a free hydroxamate NH group and is simultaneously removed during cleavage of target compounds from the solid support. The chemical route has been thoroughly tested on model compounds with several linkers, and a high yield and purity synthesis of more than 50 hydroxamates, designed to inhibit cell proliferation of breast cancer cell lines, is described.     

Silver-Catalyzed and Silver-Promoted Reactions of Isocyanides

In recent years, the silver-catalyzed and silver-promoted isocyanide reactions have attracted much attention, due to its efficiency in the formation of diverse new bonds and good reaction selectivity. A series of highly useful linear or cyclic compounds have been constructed. In this review, the recent progress in this field is described in the sequence of synthesis of five-membered heterocyclic compounds, synthesis of six-membered heterocyclic compounds, synthesis of fused cyclic compounds as well as synthesis of linear nitrogen-containing compounds.