Article
Chemistry, Applied
Denisa Hidasova, Radek Pohl, Ivana Cisarova, Ullrich Jahn
Summary: The study presents an asymmetric synthesis method for N,2,3,4,5-pentasubstituted pyrrolidines through oxidative single-electron transfer-catalyzed tandem reactions, enabling the diastereodivergent single-step synthesis of pyrrolidines with four contiguous stereogenic centers by setting the configuration of two stereocenters and generating two more in a selective manner. The stereoselectivity is rationalized by a predictive model.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Hyo Seon Sim, Hari Datta Khanal, Yong Rok Lee
Summary: In this paper, a highly efficient and atom-economic iron(III)-catalyzed three-component heteroannulation reaction is described for the construction of multifunctionalized 2-pyridones. The protocol allows rapid access to a variety of 2-pyridones with an ortho-hydroxybenzoyl and a benzoyl scaffold under simple conditions. The synthetic utility of the synthesized 2-pyridone scaffolds is demonstrated by transforming them into biologically interesting complex heterocycles.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Xue Li, Xing-Yu Chen, Bing-Ying Fan, Qun Yu, Jie Lei, Zhi-Gang Xu, Zhong-Zhu Chen
Summary: A highly efficient and direct method for synthesizing pyrroles was successfully developed by using 3-formylchromones as decarboxylative coupling partners and facilitated by microwave irradiation. This approach utilizes easily accessible starting materials, a catalytic amount of DBU without any metal catalyst, resulting in high efficiency and regioselectivity. Notably, the synthesized compounds were evaluated against five different cancer cell lines, and compound 3l selectively inhibited the proliferation of HCT116 cells.
Article
Chemistry, Applied
Xiong-Wei Liu, Xiao-Tong Lin, Cheng Zhao, Xiao-Wei Hu, Yi-Bing Xu, Yi-Lin Zheng, Xin-Ni Liu, Guo-Shu Chen, Long Chen, Yun-Lin Liu
Summary: The construction of benzopyrone-fused hydrobenzofuranones via DABCO-catalyzed [3+2] cyclization/deformylation cascade of p-quinols with 3-formylchromones is described. The reaction provides the desired products in 53-90% yields with complete diastereoselectivities under mild conditions. Furthermore, an enantioselective version with 81% ee is also achieved in the presence of Takemoto's chiral thiourea catalyst.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Krishna P. Yadavalli, Johannah E. Cummines, Chace J. Carlisle, Salvatore D. Lepore
Summary: The addition of bulky H-phosphinates to beta,beta-disubstituted alkenyl ketones under the action of a phase transfer-catalyst resulted in the formation of a new class of phosphinates with carbon quaternary centers, exhibiting unprecedented control over the relative configuration of the adjacent carbon and phosphorous chiral centers, with high diastereoselectivity in most cases.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Yang Zhang, Dan Ye, Lei Shen, Kangjiang Liang, Chengfeng Xia
Summary: A photochemical protocol is developed for the synthesis of chiral 3-hydroxyoxindoles by coupling diarylamines and alpha-ketoesters using tandem photoredox and chiral phosphoric acid catalysis. The chiral phosphoric acid plays a crucial role in controlling the stereochemistry of the downstream radical-radical cross-coupling process.
Article
Chemistry, Organic
Nicole D. Bartolo, Krystyna M. Demkiw, Elizabeth M. Valentin, Chunhua T. Hu, Alya A. Arabi, K. A. Woerpel
Summary: The stereoselectivities of reactions of allylmagnesium reagents with chiral ketones cannot be easily explained by stereochemical models, as observed in competition experiments. The irreversibility of the complexation step prevents nucleophiles from accessing a wide range of possible encounter complexes, making analysis using available models difficult. Nevertheless, stereoselective additions of allylmagnesium reagents to ketones can still occur if the carbonyl group adopts a conformation blocking one face from the approach of the reagent.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
John-Paul R. Marrazzo, Allen Chao, Yajun Li, Fraser F. Fleming
Summary: A copper iodide-Pyox complex catalyzes the first conjugate addition of diverse sulfur, nitrogen, and carbon nucleophiles to isocyanoalkenes, generating metalated isocyanoalkanes for SNi displacements. This provides a rapid route to a series of functionalized, cyclic isocyanoalkanes, laying a foundation for catalytic reactions maintaining the isocyanide group.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Zican Shen, Maria A. Vargas-Rivera, Elizabeth L. Rigby, Shuming Chen, Jonathan A. Ellman
Summary: A photocatalyzed epimerization of morpholines and piperazines has been reported using reversible hydrogen atom transfer (HAT), providing an efficient strategy for editing the stereochemical configurations of these saturated nitrogen heterocycles prevalent in drugs.
Article
Chemistry, Multidisciplinary
Emilien Le Saux, Dengke Ma, Pablo Bonilla, Catherine M. Holden, Danilo Lustosa, Paolo Melchiorre
Summary: A general iminium ion-based catalytic method for enantioselective conjugate addition of carbon-centered radicals to aliphatic and aromatic enals is reported in this study. The process uses an organic photoredox catalyst and a chiral amine catalyst to achieve consistently high levels of stereoselectivity. This catalytic platform is demonstrated to have broad applicability in intercepting various radicals, including non-stabilized primary ones that are typically challenging to engage in asymmetric processes. Additionally, the system can be used to develop organocatalytic cascade reactions, producing stereochemically dense chiral products in one step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Anshra Nousheen, Munugala Chandrakanth, Banoth Karuna Sagar, Vijaya Laxmi Somarapu
Summary: A three-component aqueous mediated mild reaction protocol was developed for the synthesis of fused diastereoselective trans 2,3-dihydrobenzofuran derivatives. The synthesized compounds were characterized by various spectroscopic techniques and their antioxidant and anticancer activities were evaluated.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Chemistry, Organic
Alexandra E. E. Bosnidou, Agathe Fayet, Cristina Cheibas, Oscar Gayraud, Sophie Bourcier, Gilles Frison, Bastien Nay
Summary: This article describes a tandem reaction between a Hock or Criegee oxidative cleavage and a nucleophilic addition onto the oxocarbenium species (specifically a Hosomi-Sakurai-type allylation), catalyzed by InCl3. It was successfully applied to the synthesis of 2-substituted benzoxacycles (chromanes and benzoxepanes), including the synthesis of the 2-(aminomethyl)chromane part of sarizotan and the total synthesis of erythrococcamide B.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Rajender Nallagonda, Rashad R. Karimov
Summary: Nucleophilic addition of diborylalkyl reagents to N-alkyl or N-acylpyridinium and related heteroarenium salts has been developed as a key step for the synthesis of nonaromatic nitrogen heterocycles that contain contiguous stereogenic centers. Derivatization of the dihydropyridine products for the synthesis of tetrahydropyridines and piperidines have also been described.
Article
Materials Science, Multidisciplinary
S. Abdelaziz, A. Zekry, A. Shaker, M. Abouelatta
Summary: Lead-free perovskite materials have been studied for photovoltaics due to their non-toxic and stable properties. A simulation study in this work on a two-terminal monolithic all lead-free tandem solar cell showed an efficiency of 7.66% by utilizing different lead-free perovskite materials for the bottom and top cells.
Article
Chemistry, Multidisciplinary
Jean Michalland, Nicolas Casaretto, Samir Z. Zard
Summary: This modular approach to substituted cyclobutylboronic esters involves successive intermolecular radical additions and reductive removal of xanthates to provide a range of 1,2- and 1,3-disubstituted cyclobutylboronic esters. The stability of the alpha-boryl radical is crucial for the success of the reaction, leveraging the stabilizing influence of the trivalent boronic ester and the slightly destabilizing cyclobutane. The chemistry described here complements existing methods by providing cyclobutylboronic esters that would be quite difficult to obtain otherwise.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
