Asian Journal of Organic Chemistry最新文献

Aziridines, with their inherent strain energy and high reactivity, serve as pivotal building blocks for constructing complex polycyclic systems. This review focuses on recent advances (2015–2025) in one-pot ring-expansion reactions of aziridine derivatives, enabling efficient synthesis of heteroatom-containing polycycles. Compared to conventional multi-step strategies, these methodologies exhibit superior atom economy and enhanced environmental compatibility, offering novel synthetic routes to pharmaceutically relevant scaffolds.

The direct reductive amination of aldehydes and ketones with primary/secondary amines is the primary approach to the synthesis of substituted secondary and tertiary amines. Generally, an external reducing agent or a hydride source is required for this transformation. However, in the recent past, many efforts have been made to perform this transformation without the need for any external hydride sources. However, most of those protocols involve harsh conditions (very high temperature or the use of microwave). In this article, we demonstrate that one of the tris(aryl)cyclopropenium salts could be used as an organic Lewis acid catalyst for the reductive amination of aryl aldehydes with indolines without the use of any external hydride source. Basically, the cyclopropenium cation (as a Lewis acid) activates the carbonyl group of the aldehyde, and the reaction proceeds through the formation of the iminium ion followed by a hydride shift from the α-carbon of another indoline to generate the desired amine. Unlike the other reported methods (without an external hydrogen source), this protocol worked well under milder conditions and many aryl aldehydes underwent reductive amination with indolines to provide the respective N-benzyl indoline derivatives in moderate to good yields.

The on-time detection of hazardous chemicals is very important in ecological environments. In this work, two new transition metal-based coordination polymers were synthesized by solvothermal method, namely [Zn(2,5-dpa)(phen)·H₂O]_n (CP-1) and [Co(2,5-dpa)(dmphen)]_n (CP-2) (2,5-dpa = 2,5-pyridinedicarboxylic acid, phen = 1,10-phenanthroline, dmphen = 2,9-dimethyl-1,10-phenanthroline). The structures of CP-1 and CP-2 were analyzed by single-crystal x-ray diffraction. The results show that CP-1 and CP-2 exhibit 1D chain structure despite the use of different auxiliary ligands. Luminescence sensing experiments showed that CP-1 can serve as a highly sensitive sensor for the selective detection of nitrobenzene (NB), as well as nitroimidazole antibiotics metronidazole (MDZ) and ornidazole (ODZ). The detection limits were found to be as low as 1.16 × 10⁻⁵ M for NB, 1.53 × 10⁻⁵ M for MDZ, and 1.26 × 10⁻⁵ M for ODZ, respectively. The possible sensing mechanisms were subsequently analyzed through in-depth experimental and computational research.

We herein reported a formal [3+3] cyclization reaction between 3-alkynyl-3-hydroxyisoindolinones and substituted phenols, which offered an efficient procedure for the preparation of 2H-chromene-based spiro-isoindolinones. 10 mol% of inexpensive catalyst (Cu(ClO₄)₂·6H₂O or Fe(OTf)₃) proved to be the best to promote the tandem regioselective 1,4-addition of phenols to the in situ generated β,γ-alkynyl-α-ketimine/intramolecular O-Michael addition to afford the desired products under mild conditions (25°C, 0.5–24 h) with a broad substrate scope (31 examples) in up to 99% yield. The synthetic utility was demonstrated by the scaled synthesis and further elaboration of the obtained products to polycyclic compounds bearing isoindolinone, 2H-chromene and five or six-membered O-heterocycles.

The increasing occurrence of algal blooms in aquatic ecosystems has heightened interest in bacillamide alkaloids owing to their pronounced algicidal activity. A critical review of the literature revealed several inconsistencies and contradictions regarding the absolute configurations and optical rotations of both naturally occurring and synthetically prepared bacillamides. To clarify these discrepancies, we developed a new enantioselective synthesis of bacillamides B–D, neobacillamide A, and their respective antipodes, starting from the enantiomers of 2-(1-hydroxyethyl)thiazole. This approach enables the efficient and stereocontrolled preparation of all target compounds, along with their enantiomers. Importantly, single-crystal X-ray diffraction analysis of the picrate salt of (–)-bacillamide D and its antipode in conjunction with their synthetic relationships, allowed an unambiguous assignment of absolute configuration. The absolute configurations and directions of optical rotation were reliably established for the entire series of bacillamides and their enantiomers. Chiral HPLC methods were also developed to determine the enantiomeric excess of the alkaloids and their counterparts. Our results correct previous stereochemical misassignments and establish a definitive correlation between structure, chirality, and optical rotation for this class of bioactive natural products. The clarified stereochemical framework provides a solid foundation for understanding structure–activity relationships and for the rational design of analogues with enhanced biological efficacy.

1,1-Dibromoalk-1-enes are a pivotal class of organic synthons and occupy an outstandingly important role in both academic and industrial communities due to their accessibility and commercial availability. The development of novel, powerful, and highly efficient strategy that employed those cost-effective reagents for the selective assembly of a great deal of structurally diverse elaborated molecular architectures has attracted considerable interest in organic synthesis, medicinal chemistry, and materials science. Over the past few decades, a resurgence of interest regarding 1,1-dibromoalk-1-enes has been witnessed, and substantial research efforts have been dedicated to investigating their reactivity and synthetic applications, with primary focus on developing efficient methodologies for constructing structurally diverse heterocyclic frameworks. In this regard, numerous reaction strategies featuring high reactivity, operational simplicity, and excellent atom economy have been systematically explored, thereby expanding the synthetic utility of 1,1-dibromoalk-1-enes in modern organic chemistry. This review summarizes the development of 1,1-dibromoalk-1-enes through different types of reactions, which could be classified into the following categories: (1) 1,1-dibromoalk-1-ene as alkenylation reagent; (2) 1,1-dibromoalk-1-ene as alkynylation reagent; (3) cyclization reaction of 1,1-dibromoalk-1-enes; and (4) other types of reactions of 1,1-dibromoalk-1-ene.

Enamides are important intermediates in organic synthesis, and the desaturation of amides represents an efficient and versatile approach for the synthesis of enamides. Recently, increasing efforts have been made to develop more efficient and sustainable methods for the desaturation of amide under different conditions. In this review, we summarized the most recent advances in the desaturation of amide, including transition-metal-catalyzed oxidative desaturation, transition-metal-free oxidative desaturation, photoinduced redox desaturation, and electrochemical anodic oxidative desaturation. The substrate scope and mechanistic details were also discussed.

Catenanes, an intriguing class of mechanically interlocked molecules (MIMs), have garnered substantial attention due to their dynamic redox-responsive behaviors and unique topological architectures. The interlocked nature of these systems allows precise control of molecular motion under electrochemical stimuli, which is valuable in designing molecular machines and devices. This review highlights contemporary advancements in the structural modification of catenanes to fine-tune their redox properties. Emphasis is placed on how changes in substitution patterns, coordination environments, and macrocyclic components curb redox behavior and facilitate reversible molecular switching. By integrating insights from both metal-containing and metal-free systems, we outline strategies for developing responsive catenane architectures with potential applications in molecular electronics, sensors, and nanomechanical devices.

A [3 + 2] cycloaddition reaction between the in situ generated azaoxyallyl cations and Weinreb amides provided an efficient approach to access 2-amino-4-Oxazolidinones. Electrophilicity of the carbonyl group in Weinreb amide leveraged such a reaction, which is otherwise elusive with regular amides. The reaction proceeds smoothly at room temperature with the aid of HFIP as a promoter. Lability of the C2 amino group under dilute HFIP was exploited to expand the chemical space at the C2 position with different nucleophiles.