Replacing an N,N-dimethylamino group in a classical fluorophore with a four membered azetidine ring provides an improved luminescence quantum yield. Herein, we extended this strategy to bioluminescent firefly luciferin analogues and evaluated its general validity. For this purpose, four types of luciferin cores were employed, and a total of eight analogues were evaluated. Among these analogues, unexpectedly, only the benzothiazole core analogue benefited from an azetidine substitution and showed enhanced bioluminescence. In addition, fluorescence measurements revealed that an azetidine substitution improved the fluorescence quantum yield by 2.3-times compared to a N,N-dimethylamino group. These findings clarify the differential effects of azetidine substituents in luciferins and present one possible strategy for enhancing photon output in benzothiazole type luciferins through a synthetic approach.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/cbic.202100310 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
New York University, Chemistry, 29 Washington Place, RM 10001, 10003, New York, UNITED STATES OF AMERICA.
Herein, we report a Lewis acid-mediated ring expansion of donor-acceptor cyclopropanes (DACs) to substituted azetidines via nucleophilic nitrogen group transfer from readily accessible iminoiodinane. This protocol operates under mild, transition-metal-free conditions, and showcases excellent chemoselectivity, along with broad functional group tolerance. We report for the first time that challenging alkyl donor-acceptor cyclopropanes can undergo ring expansion leading to aliphatic azetidines without relying on external oxidants or precious transition-metal catalysts.
View Article and Find Full Text PDFEur J Med Chem
December 2024
SynBioC Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, B-9000, Gent, Belgium. Electronic address:
There is growing interest in developing monotherapy drugs that treat inflammation caused by microbial infections, focusing on dual antimicrobial and anti-inflammatory agents with minimal side effects and high safety margins. This study synthesized and characterized a library of novel cis-4-ferrocenylazetidin-2-ones, evaluating their antimicrobial and anti-inflammatory activities. These organometallic monocyclic β-lactams showed moderate in vitro antimicrobial activity against various standard microbial strains, including yeasts and Gram-negative and Gram-positive bacteria.
View Article and Find Full Text PDFJ Org Chem
October 2024
Department of Chemistry, Villanova University, Villanova, Pennsylvania 19085, United States.
Diverse ranges of chiral nitrogen-containing heterocycles serve as a molecular toolbox for modulating a wide array of biological processes, but enantioenriched production of smaller chiral heterocycles is a bottleneck. There is a lack of general approaches for the stereoselective preparation of chiral 4-membered monocyclic C2-substituted azetidines, where many routes to different substitution types are possible, but no simple and common approach exists. To bridge this gap, inexpensive and widely available chiral -butanesulfinamides are harnessed for chiral induction with 1,3-bis-electrophilic 3-chloropropanal, providing a three-step approach to C2-substituted azetidines with aryl, vinyl, allyl, branched alkyl, and linear alkyl substituents.
View Article and Find Full Text PDFOrg Lett
September 2024
Faculty of Chemistry, University Rovira i Virgili, 43007 Tarragona, Spain.
We report an uncommon 4-- cyclization of -tosyl homopropargyl amines, catalyzed by [AuCl(PEt)]/AgOTf, to prepare stereoselective ()-2-alkylidene-1-tosylazetidine compounds. The reaction outcome contrasts with the gold-catalyzed cyclization of -tosyl homopropargyl amines containing a methyl group at the propargylic position that provides substituted 2,3-dihydropyrroles via a 5-- mechanism. The access to -tosyl homopropargyl amines is possible by the regioselective nucleophilic attack of α-diboryl alkylidene lithium salts to propargylic aziridines.
View Article and Find Full Text PDFChem Commun (Camb)
September 2024
School of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang, 473061, China.
An efficient chalcogenative annulation strategy for constructing functionalized saturated N-heterocycles from unactivated alkenes with dichalcogenides under electrochemical conditions has been presented. This protocol is applicable to mono-, di- or tri-substituted alkenes, providing a straightforward pathway to aziridines, azetidines, pyrrolidines, and piperidines with high regioselectivity. Moreover, the strategy is qualified to realize the oxychalcogenation of alkenes as well.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!