Article
Chemistry, Multidisciplinary
Maximilian Kaiser, Michael Steinacher, Florian Lukas, Peter Gaertner
Summary: A general protocol for the europium-catalyzed rearrangement of aryl-pentadienyl-ethers is described, where the mode of rearrangement and product formation is determined by the substituent para to the phenol. The reaction undergoes a [3,3] rearrangement to form a prochiral branched diene when the para-position is occupied, and a [5,5] rearrangement to form a linear conjugated diene when the para-position is free.
Article
Chemistry, Analytical
Asaad S. Mohamed, Osama M. Habib, Nouria A. Al-Awadi
Summary: Flash vacuum pyrolysis of various aryl propargyl ethers with different substituents was investigated, and mechanisms for some reactions were proposed.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Multidisciplinary Sciences
Can Yang, Xiaoyu Zhou, Lixing Shen, Zhuofeng Ke, Huanfeng Jiang, Wei Zeng
Summary: The authors developed a Mn(I)-catalyzed sigmatropic rearrangement of beta, gamma-unsaturated alcohols via C-C sigma bond activation. This rearrangement allows for selective reorganization of carbon skeletons, providing a strategy for the synthesis of complex structures with high atom and step economy.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Long-Ling Huang, Peng-Peng Lin, Yu-Xin Li, Si-Xin Feng, Fang-Hai Tu, Shuang Yang, Gui-Yang Zhao, Zhi-Shu Huang, Honggen Wang, Qingjiang Li
Summary: This study presents an in situ-generated hypervalent iodine-incorporating fluoroarylation reaction using HF·Py and aryl iodides to react with benzylidenecyclopropanes, providing valuable monofluorinated products for organic synthesis with mild reaction conditions.
Article
Chemistry, Organic
Seo-Jung Han, Marchello A. Cavitt, Brian M. Stoltz
Summary: An efficient method for the direct synthesis of eight-membered nitrogen-containing heterocycles from secondary and tertiary alcohols was developed. This operationally simple reaction tolerates various functional groups and is applicable to the synthesis of diverse medium-sized ring nitrogen-containing heterocycles.
Article
Chemistry, Organic
Bubwoong Kang, Takuto Oe, Yuki Shimizu, Hirosato Takikawa
Summary: This article describes the formation of a 3-chloro-2H-chromene through a cascade reaction and the synthesis of three different 3-isoflavan derivatives through a Suzuki cross-coupling reaction. The divergent total synthesis of isoflavan natural products was also achieved through a heterogeneous catalytic hydrogenation.
Article
Chemistry, Organic
Anastasia Vepreva, Alexander Yanovich, Dmitry Dar'in, Grigory Kantin, Alexander Bunev, Mikhail Krasavin
Summary: This article describes a straightforward method to synthesize novel spiro[benzofuran-2,3'-pyrrolidine]-2',5'-diones through the Rh2(esp)2-catalyzed insertion of carbenes derived from diazo arylidene succinimides (DAS) into the O-H bond of phenols. The initial adducts undergo a thermally promoted Claisen rearrangement followed by a DABCO-catalyzed intramolecular 5-exo-trig oxa-Michael addition to obtain the final products.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Souta Misawa, Asaki Miyairi, Yoshihiro Oonishi, Steven P. Nolan, Yoshihiro Sato
Summary: Polarized alkynes such as ynol ethers and ynamides undergo Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reactions with allylic alcohols, proceeding under mild conditions with high regioselectivity. The resulting gamma,delta-unsaturated esters or amides are formed in an atom-economical manner using the [Au(IPr)NTf(2)] catalyst.
SYNTHESIS-STUTTGART
(2021)
Article
Multidisciplinary Sciences
Mengjie Hu, Yanping Liu, Yuchen Liang, Taotao Dong, Lichun Kong, Ming Bao, Zhi-Xiang Wang, Bo Peng
Summary: In this study, the authors demonstrated a dearomatization method driven by [5,5]-rearrangement, which enabled the conversion of aryl sulfoxides into di- and trifunctionalized compounds. Mechanistic studies revealed the selectivity and generation of intermediates in the reactions.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ching-Nung Chen, Wei-Min Cheng, Jian-Kai Wang, Tzu-Hsuan Chao, Mu-Jeng Cheng, Rai-Shung Liu
Summary: This study demonstrates gold-catalyzed [3+2]-annulations of alpha-diazo ketones with highly substituted cyclopentadienes, resulting in bicyclic 2,3-dihydrofurans with high regio- and stereoselectivity. Enantioselective annulations can also be achieved using chiral forms of gold and phosphoric acid. The mechanistic analysis suggests that cyclopentadienes act as nucleophiles attacking gold carbenes, leading to gold enolates that complex with chiral phosphoric acid to enhance enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jingran Zhang, Ayesha Jalil, Jiaxin He, Zhenyang Yu, Yifu Cheng, Guangchen Li, Yunfei Du, Kang Zhao
Summary: A series of alkoxylated isobenzofuranones were conveniently synthesized through a cascade reaction. The reaction mechanism involves lactonization, aryl migration, and alkoxylation processes, and organocatalytic and chiral reactions were also explored.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Arijit Hazra, Asit Ghosh, Neeraj Yadav, Prabal Banerjee
Summary: The first asymmetric (3+3)-cycloaddition of ortho-substituted phenyl nitrones with aryl cyclopropane carbaldehydes has been successfully demonstrated using secondary amine catalysts. While other ortho-substituents led to 1,2-oxazinanes, ortho-hydroxy groups provided a novel class of tetrahydrochromeno-1,2-oxazine cores via rare 1,3-aryl migration followed by cyclization. An unusual type of asymmetric approach was also recognized.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Arijit Hazra, Asit Ghosh, Neeraj Yadav, Prabal Banerjee
Summary: The first asymmetric (3+3)-cycloaddition of ortho-substituted phenyl nitrones with aryl cyclopropane carbaldehydes has been achieved using secondary amine catalysts. While other ortho-substituents gave 1,2-oxazinanes, ortho-hydroxy compounds provided a novel class of tetrahydrochromeno-1,2-oxazine cores through rare 1,3-aryl migration followed by cyclization. An unusual type of asymmetric approach was also discovered.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Henrik Weber, Nils Drouve, Lana Kortenbrede, Sherif El Sheikh
Summary: In this study, the synthesis of aryl derivatives of ketamine and its major metabolites was reported using a Diels-Alder reaction, resulting in a substituted cyclohexane core structure. The method demonstrated broad applicability.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Mathias Ryslett Lepsoe, Aleksander Granum Dalevold, Lise-Lotte Gundersen
Summary: Microwave-assisted Claisen rearrangement of 8-allyloxyphenanthridines allows for the formation of carbon-carbon bonds at the phenanthridine 7-position. The reaction exhibits excellent regioselectivity and high chemical yields. If the 7-position is substituted, rearrangement to C-9 occurs with lower reactivity. Rearrangement of 8-allyloxy-5,6-dihydrophenanthridines (phenanthridines with a saturated B-ring) results in a mixture of products at both the 7- and 9-positions. DFT calculations support the experimental findings.
