10.1039/b612114d
The research focuses on the chemistry of enediynyl azides, specifically the spontaneous activation of a nonaromatic enediynyl azide under ambient conditions. The study explores the synthesis and reactivity of enediyne scaffolds 1–4, which contain alkene and azide functionalities. The experiments involved coupling bromoalkenes with 3-butyn-1-ol under Sonogashira conditions, followed by mesylation and conversion to azides. The synthesized compounds were analyzed using techniques such as FTIR, 1H-NMR, 13C-NMR, and ESI mass spectrometry to monitor the disappearance of azide peaks, the presence of specific functional groups, and the formation of new products. The research also observed the intramolecular cycloaddition of the aromatic enediyne 3 and the nonaromatic enediyne 4, leading to the formation of triazoline fused enediyne 22 and benzotriazine derivative 27, respectively. The study suggests that the mechanism involves initial dipolar cycloaddition with the alkyne, followed by rearrangement and cyclization, ultimately leading to the formation of diradicals that can cleave DNA under ambient conditions. This research contributes to the understanding of enediyne reactivity and has implications for the development of potential DNA-cleaving agents.
10.1055/s-0029-1219779
The research focuses on the development of an efficient method for the synthesis of 4-aryl-5,6-dihydropyrans, which are heterocyclic compounds found in many biologically active natural products and pharmaceuticals. The purpose of this study was to create a one-pot, three-component synthesis via Prins-Friedel-Crafts reaction, utilizing aldehydes or epoxides, homopropargylic alcohols, and arenes, all promoted by boron trifluoride etherate as a Lewis acid catalyst. The conclusions drawn from the research indicate that this method is effective for synthesizing 4-aryl-dihydropyrans with good to moderate yields, without the formation of 4-halosubstituted side products, and can be extended to epoxides when aldehydes are not readily accessible. The chemicals used in the process include a range of aldehydes, homopropargylic alcohols, various arenes, and boron trifluoride etherate as the catalyst.