A series of novel polyacetylene substituted 2-hydroxy acids and derivatives were prepared and characterized. Alkylation of butane-2,3-diacetal (BDA) protected glycolic acid with iodoalkyl substituted polyacetylene compounds gave the corresponding diacetal protected polyacetylene substituted 2-hydroxy acids. Diacetal deprotection through acid mediated hydrolysis, transesterification or aminolysis afforded the 2-hydroxy-polyacetylenic acid, ester or amide derivatives. Twenty one of these novel compounds were tested against 10 microbes of clinical importance and several of them showed good antimicrobial activity, in particular against Pseudomonas aeruginosa.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bmcl.2010.06.020 | DOI Listing |
J Phys Chem Lett
January 2025
Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States.
What if an experiment could combine the power of cycloaddition and cross-coupling with the formation of an aromatic molecule in a single collision? Crossed molecular beam experiments augmented with electronic structure and statistical calculations provided compelling evidence on a novel radical route involving 1,3-butadiynyl (HCCCC; X∑) radicals synthesizing (substituted) arylacetylenes in the gas phase upon reactions with 1,3-butadiene (CHCHCHCH; XA) and 2-methyl-1,3-butadiene (isoprene; CHC(CH)CHCH; XA'). This elegant mechanism merges two previously disconnected concepts of cross-coupling and cycloaddition-aromatization in a single collision event via the formation of two new C(sp)-C(sp) bonds and bending the 180° moiety of the linear 1,3-butadiynyl radical out of the ordinary by 60° to 120°. In addition to its importance to fundamental organic chemistry, this unconventional mechanism links two previously separated routes of gas-phase molecular mass growth processes of polyacetylenes and polycyclic aromatic hydrocarbons (PAHs), respectively, in low-temperature environments such as in cold molecular clouds like the Taurus Molecular Cloud (TMC-1) and in hydrocarbon-rich atmospheres of planets and their moons such as Titan, which revises the established understanding of low-temperature molecular mass growth processes in the Universe.
View Article and Find Full Text PDFMolecules
December 2024
Department of Chemistry, William & Mary, Williamsburg, VA 23185, USA.
The development of new antibiotics with unique mechanisms of action is paramount to combating the growing threat of antibiotic resistance. Recently, based on inspiration from natural products, an asymmetrical polyacetylene core structure was examined for its bioactivity and found to have differential specificity for different bacterial species based on the substituents around the conjugated alkyne. This research further probes the structural requirements for bioactivity through a systematic synthesis and investigation of new compounds with variable carbon chain length, alkynyl subunits, and alcohol substitution.
View Article and Find Full Text PDFPrecis Chem
December 2023
Department of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing, 401331, P.R. China.
RSC Adv
March 2024
Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute of Organic Chemistry and Macromolecular Chemistry Universitätsstrasse 1 D-40225 Düsseldorf Germany
A novel generation of 7-aryl phenothiazinyl substituted polyacetylenes is readily accessible controlled rhodium-catalyzed polymerization of the corresponding 3-ethynyl 7-aryl phenothiazines. The monomers are synthesized by Suzuki coupling, Heck coupling, or Buchwald-Hartwig amination, and Bestmann-Ohira reaction. This allows for the introduction of electron donating and releasing substituents with different ligation patterns.
View Article and Find Full Text PDFFitoterapia
June 2024
State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China. Electronic address:
Artemdubosides A-E (1-5), the first examples of natural polyacetylenes substituted by 6'-O-crotonyl β-glucopyranoside, and artemdubosides F-G (6-7) that were two unusual polyacetylenes featuring a 6'-O-acetyl β-glucopyranoside moiety, were isolated from Artemisia dubia var. subdigitata. Their structures were elucidated based on the spectral data including HRESIMS, UV, IR, 1D and 2D NMR, and ECD calculations.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!