氮杂环丙烷开环反应的研究进展

介绍了碳、氧、硫、氮及含其他杂原子等亲核试剂对氮杂环的开环反应,阐述了烷基、芳基、烯胺、烯醇、烯烃等负碳离子对氮杂环的开环研究.     

An Organocatalytic Synthesis of cis‐N‐Alkyl‐ and N‐Arylaziridine Carboxylates

An extremely mild protocol that employs readily available starting materials, i.e., aldehyde, amine and alkyl diazoacetate, returns structurally diverse N‐substituted‐C‐2/3‐difunctionalised aziridines in excellent yields and stereoselectivities when pyridinium triflate is incorporated as an organocatalyst. The reaction process is environmentally benign affording water and nitrogen as the only by‐products. This racemic protocol paves the way for the development of novel asymmetric organocatalysts capable of generating optically active aziridines.     

Synthetic Applications and Methodological Developments of Donor−Acceptor Cyclopropanes and Related Compounds

Donor−acceptor cyclopropanes are convenient precursors to reactive and versatile 1,3-dipoles, and have found application in the synthesis of a variety of carbo- and heterocyclic scaffolds. This perspective review details our laboratory's use of donor−acceptor cyclopropanes as intermediates toward the total synthesis of various natural products. We also discuss our work in the development of novel cycloadditions and rearrangements of donor−acceptor cyclopropanes and aziridines, as well as an example of an aryne insertion proceeding via fragmentation of a transient donor−acceptor cyclobutane.     

3-Arylaziridine-2-carboxylic Acid Derivatives and (3-Arylaziridin-2-yl)ketones: The Aziridination Approaches

Aziridination reactions represent a powerful tool in aziridine synthesis. Significant progress has been achieved in this field in the last decades, whereas highly functionalized aziridines including 3-arylated aziridine-2-carbonyl compounds play an important role in both medical and synthetic chemistry. For the reasons listed, in the current review we have focused on the ways to obtain 3-arylated aziridines and on the recent advances (mainly since the year 2000) in the methodology of the synthesis of these compounds via aziridination.     

Silver iodide catalyzed the three-component reaction between terminal alkynes,carbon disulfide,and aziridines

ABSTRACT

A novel catalytic reaction involving terminal alkynes, carbon disulfide, and aziridines has been described. In this transformation, silver-acetylides react with carbon disulfide and aziridines to form 1,4-thiomorpholine molecules in good yields. The optimum conditions developed using silver iodide and (i-Pr)₂EtN in DMF at 70°C.     

Lewis酸催化氮杂环丙烷的亲核开环反应

介绍了氮杂环丙烷开环反应的一般方法和反应机理,系统地总结了近10年来多种Lewis酸催化的各类亲核试剂对氮杂环丙烷的亲核开环反应。     

碳亲核试剂与氮杂环丙烷开环反应的研究进展

氮杂环丙烷化合物是有机合成中重要的杂环化合物之一,其开环反应越来越受到有机化学家的关注.本文综述了近年来各类碳亲核试剂与氮杂环丙烷开环反应的研究进展,大多具有反应条件温和、易控制、区域选择性好、收率高等优点.     

Nucleophilic ring opening of aziridines

This account of research work on nucleophilic ring opening (NRO) of aziridines (Az's) demonstrates the broad synthetic scope of this reaction, inclusive secondary reactions, and it discusses the special mechanistic fundamentals and details as well as mechanistic variants. Formation of a C–C bond by NRO is the red thread in this report. A central mechanistic aspect is the quality of the leaving group in Az bases, aziridinium ions and activated Az's (acyl, sulfonyl; double activation). Factors controlling the regioselectivity of NRO are dealt with as well as the influence of the nitrogen pyramid. Competing reactions include carbonyl attack (acylated Az's) and electron transfer with cases of pseudo-NRO (multistep radical paths).     

Reactivity of Donor-Acceptor Cyclopropanes with Saturated and Unsaturated Heterocyclic Compounds

Strain in the ring engenders versatile reactivity that can be utilized for the synthesis of complex molecules by the assimilation of suitable substituents. In this context, vicinal donor-acceptor cyclopropanes (DACs) serve as three-carbon synthetic equivalents in organic synthesis from the last few decades. Owing to their zwitterionic nature, they have been frequently utilized in [3+n]-annulation reactions with different dipolarophiles like aldehydes, imines, oximes, epoxides, aziridines, etc. This review highlights developed synthetic tools for annulation reactions of vicinal donor-acceptor cyclopropanes with saturated and unsaturated heterocyclic compounds.     

Aminolysis of Aziridines Catalyzed by Samarium Iodides

Abstract  

Samarium diiodide is an efficient catalyst for the aminolysis of either activated or non activated aziridines with aromatic amines. A variety of N-diprotected β-diamines has been prepared including new products. The comparison of the N-protecting groups of aziridines in reactions catalyzed by samarium diiodide or by samarium iodobinaphtholate indicates that N-Boc protection leads to the best results.     

A rapid regioselective ring-opening of aziridines with potassium thiocyanate using ammonium-12-molybdophosphate

Ammonium-12-molybdophosphate, a heterogeneous catalyst, has been utilized for the first time for rapid (within 15–20 min) regioselective ring-opening of aziridines with KSCN at room temperature to form the corresponding β-aminothiocyanates in high yields.     

Gold(III) Chloride/Silver Triflate: A Highly Efficient Catalyst for Ring‐Opening Reaction of Aziridines with Electron‐Rich Arenes

Gold(III) chloride/silver triflate was found to a highly efficient catalyst in the ring‐opening of aziridines with electron‐rich arenes and the desired β‐arylamines were afforded in good to excellent yields under mild reaction conditions.     

Cis-Configured aziridines are new pseudo-irreversible dual-mode inhibitors of Candida albicans secreted aspartic protease 2

A series of cis-configured epoxides and aziridines containing hydrophobic moieties and amino acid esters were synthesized as new potential inhibitors of the secreted aspartic protease 2 (SAP2) of Candida albicans. Enzyme assays revealed the N-benzyl-3-phenyl-substituted aziridines 11 and 17 as the most potent inhibitors, with second-order inhibition rate constants (k(2)) between 56,000 and 121,000 M(-1) min(-1). The compounds were shown to be pseudo-irreversible dual-mode inhibitors: the intermediate esterified enzyme resulting from nucleophilic ring opening was hydrolyzed and yielded amino alcohols as transition-state-mimetic reversible inhibitors. The results of docking studies with the ring-closed aziridine forms of the inhibitors suggest binding modes mainly dominated by hydrophobic interactions with the S1, S1', S2, and S2' subsites of the protease, and docking studies with the processed amino alcohol forms predict additional hydrogen bonds of the new hydroxy group to the active site Asp residues. C. albicans growth assays showed the compounds to decrease SAP2-dependent growth while not affecting SAP2-independent growth.     

氮杂环丙烷与腈的[3+2]环加成反应生成咪唑啉的研究进展

咪唑啉是一种非常重要的药物中间体,其通过氮杂环丙烷与腈的[3+2]环加成反应是非常有效合成方法.综述了这种方法的研究进展,并且进行了评价与展望.     

Non-Aziridination Approaches to 3-Arylaziridine-2-carboxylic Acid Derivatives and 3-Aryl-(aziridin-2-yl)ketones

Highly functionalized aziridines, including compounds with aromatic moieties, are attractive substrates both in synthetic and medical areas of chemistry. There is a broad and interesting set of synthetic methods for reaching these compounds. Aziridination represents the most explored tool, but there are several other more specific, less well-known, but highly promising approaches. Therefore, the current review focuses on recently described or updated ways to obtain 3-arylated aziridines via different non-aziridination-based synthetic methods, reported mainly since 2000. The presented methods belong to two main directions of synthesis, namely, cyclization of open-chain substrates and rearrangement of other heterocycles. Cyclization of open-chain substrates includes the classic Gabriel-Cromwell type cyclization of halogenated substrates with amines, base-promoted cyclization of activated aminoalcohols (or its analogues), and the oxidative cyclization of β-dicarbonyls. Rearrangements of other heterocycles are presented as the Baldwin rearrangement of 4-isoxazolines, the cycloaddition of 1.3-dipoles or dienes to 2H-azirines, and the addition of C- and N-nucleophiles to the double bond of azirines.     

Direct Aza‐Darzens Aziridination of N‐Tosylimines with 2‐Bromomalonates for the Synthesis of Highly Functionalized Donor‐Acceptor Aziridines

An approach to highly functionalized donor‐acceptor aziridines by the aziridination of N‐tosylimines and 2‐bromomalonates in the presence of sodium hydride under mild conditions has been developed. The high‐yielding reaction has a relatively broad scope and can be easily scaled up to the gram level.     

Rational design of aziridine-containing cysteine protease inhibitors with improved potency: studies on inhibition mechanism

To enable a rational design of improved cysteine protease inhibitors, the present work investigates trends in the inhibition potency of aziridine derivatives with a substituted nitrogen center. To predict the influence of electron-withdrawing substituents, quantum chemical computations of the ring opening of N-formylated, N-methylated, and N-unsubstituted aziridines with thiolate were performed. They revealed that the N-formyl group leads to a strong decrease of the reaction barrier and a considerable increase in exothermicity due to stabilization of the transition state. In contrast, a nucleophilic attack at the carbonyl carbon atom is characterized by very low reaction barriers, suggesting a reversible reaction, thus providing the theoretical background for the reversible inhibition of cysteine proteases by peptidyl aldehydes. Reactions of aziridine building blocks (diethyl aziridine-2,3-dicarboxylate 1, diethyl 1-formyl aziridine-2,3-dicarboxylate 2) with a model thiolate in aqueous solution which were followed by NMR spectroscopy and mass spectrometry, showed the N-formylated compound 2 to readily undergo a ring-opening reaction. In contrast, the reaction of 1 with the thiolate is much slower. Enzyme assays with the cysteine protease cathepsin L showed 2 to be a 5000-fold better enzyme inhibitor than 1. Dialysis assays clearly proved irreversible inhibition. These experiments, together with the results obtained with the model thiolate, indicate that the main inhibition mechanism of the N-formylated aziridine 2 is the ring-opening reaction rather than the reversible attack of the active site cysteine residue at the carbonyl carbon atom.     

Epaminierungen. II. Herstellung von Aziridinen aus Olefinen und N-Halogenaminen

Epaminations. II. Synthesis of Aziridines from Olefins and N-Haloamines Chloramine, dichloramine as well as the N-chloro- and N-bromo-derivatives of primary aliphatic amines react with olefins to give aziridines. Yields up to 75% are obtained by the reaction of N.N-dibromamines with styrene-type olefins. The reaction is shown to proceed stereo-unspecifically by a chain-mechanism with the radical R N· Br as the chain carrier.     

德士古气化炉氮气切断阀执行机构技术改造

气化炉氮气切断阀动作时间不满足工艺要求,经常导致气化炉投料失败,为不影响公司正常生产,我们对氮气切断阀执行机构进行技术改造以满足工艺要求。本文叙述了技术改造的方案及过程。     

Chalkonaziridine. IV. Vergleich des spektroskopischen und massenspektrometrischen Verhaltens von trans-Chalkonaziridinen und trans-Chalkonepoxiden

Chalcone Aziridines. IV. Comparison of Spectroscopical and Mass Spectrometrical Behavior of trans-Chalcone Aziridines and trans-Chalcone Epoxides The aziridines 1 were compared with epoxides 2 by their i.r. and n.m.r. spectroscopical behavior and the threemembered ring electron densities. In the masse spectra we found not only identical path-ways i. e. the formation of M^⊕ and Ar₂CH^⊕ ions and onium or aryl fragmentation, but also differences as the formation of [M–17]^⊕ ions for 1 and carbonyl rearrangements for 2 .