Article
Chemistry, Multidisciplinary
David Egea-Arrebola, F. Wieland Goetzke, Stephen P. Fletcher
Summary: Rhodium-catalyzed enantioselective additions of aryl and vinyl boronic acids to cyclobutenone ketals are described in this work. The reaction involves enantioselective carbometalation to give cyclobutyl-rhodium intermediates, followed by beta-oxygen elimination to afford enantioenriched enol ethers. Overall, this addition serves as a surrogate for Rh-catalyzed 1,4-additions to cyclobutenone.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Arun-Libertsen Lawzer, Thomas Custer, Jean-Claude Guillemin, Robert Kolos
Summary: While the archetypal free phosphinidene, H-P, has been studied for over a century, reports on uncomplexed, univalent phosphorus compounds are very sparse. Here, the production of HCCP in solid argon through UV-induced rearrangement and subsequent dehydrogenation of phosphapropyne, CH3CP, was demonstrated. The migration of hydrogen atoms along the CCP backbone of CH3CP resulted in the production of previously unobserved species 1-phosphapropadiene, CH2=C=PH, followed by the ethynylphosphine, HCCPH2.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Karel Skoch, Constantin G. Daniliuc, Gerald Kehr, Gerhard Erker
Summary: The compound undergoes a rare reaction with a borane to form a unique unsaturated compound, capable of reducing carbon monoxide and reacting with nitriles to produce a boron-containing heterocycle derivative.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Xu-Jie Wang, Huan-Huan Liu, Jun Kee Cheng, Shao-Hua Xiang, Bin Tan
Summary: A sulfur stereogenic center is important for pharmaceuticals and chiral auxiliaries. While methods for enantioselectively constructing sulfur stereocenters have been developed, the synthesis and isolation of S-stereogenic ylides has been elusive. We successfully developed the first catalytic enantioselective synthesis of sulfonium ylides with a chiral sulfur center, using judicious substrate design and a copper-catalyzed intramolecular carbene transfer reaction.
Article
Chemistry, Multidisciplinary
Peng Yan, Changxu Zhong, Jie Zhang, Yu Liu, Huayi Fang, Ping Lu
Summary: Cyclobutenone has been utilized as a reactive dienophile in Diels-Alder reactions, with this study presenting the first enantioselective example using chiral oxazaborolidine-aluminum bromide catalysis. Additionally, a total synthesis of (-)-kingianin F was achieved for the first time through the enantioenriched cycloadduct bicyclo[4.2.0]octane derivative.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Shengda Wang, Xingcheng Li, Guilin Zhuang, Muqing Chen, Pingsen Huang, Shangfeng Yang, Pingwu Du
Summary: This study reports a fixed two-bond approach for direct functionalization of small strained macrocyclic nanorings, producing large pi-extended molecular crowns. This synthesis strategy could pave the way towards the pi-extension of strained conjugated macrocycles and their potential applications in electron-transport devices.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Peng Yan, Jia Zhang, Licheng Lu, Huayi Fang, Ping Lu
Summary: In this study, we report a new method for enantioselective Diels-Alder reaction catalyzed by a chiral catalyst COBI, which enables the asymmetric reaction of 2,3-disubstituted cyclobutenones with various dienes. This method successfully synthesizes bicyclo[4.2.0]octane derivatives with two contiguous angular quaternary centers, demonstrating intriguing structural patterns.
Article
Chemistry, Multidisciplinary
Aleksa Milosavljevic, Connor Holt, Alison J. Frontier
Summary: Herein, a one-pot nitrogen-interrupted halo-Prins/halo-Nazarov coupling cascade is reported, which enables the synthesis of functionalized cyclopenta[b]indolines with up to four contiguous stereocenters by joining an enyne and a carbonyl partner. A general method for alkynyl halo-Prins reaction of ketones is provided for the first time, allowing the formation of quaternary stereocenters. The outcomes of secondary alcohol enyne couplings and the impact of aniline enyne substituents on the reaction are also described.
Article
Water Resources
Ryuichiro Shinohara, Kenji Tsuchiya, Ayato Kohzu
Summary: The study focused on the role of particulate organic phosphorus (POP) in the phosphorus cycle in the Sakura River, Japan. Findings indicated that concentrations of suspended particles and particulate phosphorus increased after rain events during irrigation, with POP accounting for 42.4% of PP concentrations. Changes in phosphorus composition were observed during decomposition experiments, with a decrease in organic phosphorus proportion as DNA-P disappeared from the PP. Additionally, the presence of suspended particles was found to increase DOP mineralization rates.
JOURNAL OF HYDROLOGY-REGIONAL STUDIES
(2022)
Article
Chemistry, Organic
Xiaoqin Ning, Yongke Chen, Qian Ye, Fangdong Hu, Ying Xia
Summary: A palladium-catalyzed cross-coupling reaction between cyclobutenone N-tosylhadrazones and organohalides has been developed. The reaction involves the generation of a strained allylpalladium intermediate and subsequent electrocyclic ring opening and β-hydride elimination to produce conjugated enynes and enallenes. The broad substrate scope, high yields, and tunable product diversity make this protocol potentially valuable in organic synthesis.
Article
Chemistry, Multidisciplinary
Yangxu Du, Jiao Hou, Qing Lu, Wei Hao, Wenquan Yu, Junbiao Chang
Summary: A new synthetic method has been developed for the transformation of primary benzhydrylamines into aromatic secondary amine derivatives using an iodine-mediated 1,2-aryl migration reaction. The process is operationally simple and can be conducted successfully on a gram scale.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Sean H. Kennedy, Balu D. Dherange, Kathleen J. Berger, Mark D. Levin
Summary: This reaction successfully removes nitrogen from organic molecules, promoting carbon-carbon coupling reactions and expanding the accessible chemical space.
Article
Chemistry, Multidisciplinary
Tatsuya Morofuji, Shota Nagai, Airi Watanabe, Kota Inagawa, Naokazu Kano
Summary: This study reports a new activation mode of amine catalysis called streptocyanine, which enables the conversion of pyridine rings to benzene rings. By N-arylation of pyridines with an alkenyl substituent at the 3-position, N-arylpyridiniums are generated, which can react with a catalytic amount of piperidine to form streptocyanine intermediates. These intermediates can then undergo a ring-closing reaction to form a benzene ring, releasing the amine catalyst. Mechanistic studies support the proposal that streptocyanine is an intermediated in this catalytic process.
Article
Chemistry, Organic
Joshua A. Malone, Satish Chandra Philkhana, Jacob R. Stepherson, Fatimat O. Badmus, Frank R. Fronczek, Rendy Kartika
Summary: This article describes a new synthetic reaction that can generate all-carbon bisquaternary centers at the opposing side of alpha-carbons in cyclohexanone with four different substituents in a controlled manner.
Article
Environmental Sciences
Isis S. P. C. Scott, Chad J. Penn
Summary: Steel slag has been proven to effectively remove phosphorus and mitigate pollution in freshwater systems. However, the oversimplification of steel slag behavior as a phosphorus sorption material calls for individual characterization of slag samples to determine their phosphorus removal capacity. Coating steel slags with aluminum significantly improved phosphorus removal performance, especially under rapid flows.
