Synthesis of the C(7)-C(22) sector of (+)-acutiphycin via O-directed double free radical alkyne hydrostannation with Ph3SnH/Et3B, double I-Sn exchange, and double Stille coupling.

Org Lett

The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom.

Published: February 2014

Herein a new double O-directed free radical hydrostannation reaction is reported on the structurally complex dialkyldiyne 11. Through our use of a conformation-restraining acetal to help prevent stereocenter-compromising 1,5-H-atom abstraction reactions by vinyl radical intermediates, the two vinylstannanes of 10 were concurrently constructed with high stereocontrol using Ph3SnH/Et3B/O2. Distannane 10 was thereafter elaborated into the bis-vinyl iodide 9 via O-silylation and double I-Sn exchange; double Stille coupling of 9, O-desilylation, and oxidation thereafter furnished 8.

Download full-text PDF

Source
http://dx.doi.org/10.1021/ol500050pDOI Listing

Publication Analysis

Top Keywords

free radical
8
double i-sn
8
i-sn exchange
8
exchange double
8
double stille
8
stille coupling
8
double
6
synthesis c7-c22
4
c7-c22 sector
4
sector +-acutiphycin
4

Similar Publications

Exploring the synergistic effect of NaOH/NaClO absorbent in a novel wet FGD scrubber to control SOx/NOx emissions.

Environ Monit Assess

January 2025

International Joint Research Center For Green Energy and Chemical Industry, School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.

Escalating SOx and NOx emissions from industrial plants necessitates customized scrubbing solutions to improve removal efficiency and tackle cost limitations in existing wet FGD units. This work investigates the real-time intensified removal pathways via an innovative two-stage countercurrent spray tower configuration strategically integrating NaOH (M) and NaOH/NaClO (M/M) to remove SOx and NOx emissions simultaneously from the industrial stack through a comprehensive parametric study of absorbents concentration, reaction temperature, gas flow rate, liquid to gas ratio (F/F), and absorbent showering head. Flue gas stream comprising SO bearing 4500 ppm, SO bearing 300 ppm, 70 ppm NO, and 50 ppm NO brought into contact with two scrubbing solutions as M, and a complex absorbent of M/M at varying respective ratios.

View Article and Find Full Text PDF

De novo root regeneration (DNRR) involves activation of special cells after wounding, along with the converter cells, reactive oxygen species, ethylene, and jasmonic acid, also playing key roles. An updated DNRR model is presented here with gene regulatory networks. Root formation after tissue injury is a type of plant regeneration known as de novo root regeneration (DNRR).

View Article and Find Full Text PDF

Mitochondria represent pivotal cellular organelles endowed with multifaceted functionalities encompassing cellular respiration, metabolic processes, calcium turnover, and the regulation of apoptosis, primarily through the generation of reactive oxygen species (ROS). Perturbations in mitochondrial dynamics have been intricately linked to the etiology of numerous cardiovascular pathologies, such as heart failure, ischemic heart disease, and various cardiomyopathies. Notably, recent attention has been directed towards the detrimental impact of micro- and nanoplastic pollution on mitochondrial integrity, an area underscored by a paucity of comprehensive investigations.

View Article and Find Full Text PDF

Disproportion between reactive oxygen species (ROS) production and the body's antioxidant system can cause oxidative stress, which is considered a common denominator in various pathological conditions, including cardiovascular diseases, aging, and cognitive disorders. The generation of free radicals, which occurs through partial reduction of oxygen, can quickly overwhelm the endogenous antioxidant system capacity of the cell. This causes lipid, protein, DNA and RNA damage, inflammation, and overall cell degeneration, which can be mitigated by various antioxidants.

View Article and Find Full Text PDF

Visible-light-driven metal- and photocatalyst-free cascade 1,4-HAT and dearomative spirocyclization of -benzylacrylamides are described for sustainable synthesis of a variety of pharmaceutically important γ-ketoamides and 2-Azaspiro[4.5]decanes in one pot in good to excellent yields. Readily accessible and nontoxic materials, expensive Ir or Ru photocatalyst-free mild conditions, excellent functional group tolerance, operational simplicity, and scalability enhance the practical value of this protocol.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!