Article
Chemistry, Organic
Guiqing Xu, Qi Chen, Fen Wu, Dachang Bai, Junbiao Chang, Xingwei Li
Summary: The Rh(III)-catalyzed C-H activation of N-phenoxyacetamides and chemodivergent coupling to alkylidenecyclopropanes has been achieved, offering a new synthetic route to 3-ethylidenedihydrobenzofurans or dienes with excellent selectivity. The reactions proceeded under mild conditions with a good substrate scope and solvent-controlled selectivity.
Article
Chemistry, Inorganic & Nuclear
Tobias Kaper, Connor W. W. Frye, Ian A. A. Tonks
Summary: This study examines the potential of allenes as selective coupling partners in a Ti-catalyzed [2 + 2 + 1] pyrrole synthesis reaction. The results show that 1,2-cyclononadiene acts as a regioselective insertion coupling partner, producing 2,3-annulated pyrroles through reaction with alkynes and azobenzene. Additionally, propadiene undergoes both [2 + 2] cycloaddition and insertion in a highly regioselective manner, yielding exclusively N-phenyl-2,5-dimethylpyrrole, while propyne results in an unselective regioisomeric mixture. This highlights the complementary or better selectivity provided by allenes compared to alkynes in multicomponent synthesis.
Article
Chemistry, Organic
Wenlong Ren, Mingzhou Wang, Jianqiong Guo, Jintao Zhou, Jianxiao Chu, Yuan Shi, Yian Shi
Summary: A regioselective Pd-catalyzed hydrocarboxylation of terminal olefins with HCOOH is described. A wide variety of branched carboxylic acids can be obtained easily under mild reaction conditions with high regioselectivities. The operation of the reaction is simple and does not require handling toxic CO. The ligand and LiCl play important roles in reaction reactivity and selectivity.
Article
Chemistry, Physical
Stefan Weber, Luis F. Veiros, Karl Kirchner
Summary: Efficient manganese-catalyzed dimerization of terminal alkynes to produce 1,3-enynes is achieved in this study. The reaction is atom economic, utilizing an inexpensive catalyst with high efficiency and selectivity.
Article
Chemistry, Multidisciplinary
Liye Chen, Katerina G. Malollari, Adam Uliana, John F. Hartwig
Summary: The lack of functional groups in polyolefins limits their applications, but the functionalization of C-H bonds holds promise for incorporating functionalities into ethylene and linear alpha-olefins polymers. The selective functionalization of polyolefins derived from branched alkenes has not been achieved due to steric effects, but a polyfluorinated ruthenium-porphyrin catalyst successfully incorporates ketone units into polyisobutene without chain cleavage, resulting in a thermally stable polymer with enhanced wetting properties.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Lixia Liu, Chengming Wang
Summary: This copper-catalyzed reaction offers a simple procedure, easily accessible materials, and good tolerance towards functional groups. It can be scaled up to gram scale and applied smoothly in the late-stage modification of bioactive molecule derivatives.
REACTION CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Organic
Somratan Sau, Arghadip Ghosh, Majji Shankar, Manash Protim Gogoi, Akhila Kumar Sahoo
Summary: The study demonstrates a unprecedented thioamide-directed cobalt-catalyzed umpolung annulation reaction for the synthesis of highly substituted 2-amidoindenones. The transformation shows regioselectivity and constructs diverse structures, showcasing broad scope and success on a gram scale.
Article
Chemistry, Multidisciplinary
Yan-Dong Zhang, Xiao-Yu Li, Qian-Kun Mo, Wen-Bin Shi, Jia-Bao Zhao, Shou-Fei Zhu
Summary: In this study, we developed new Co complexes with cyclopropane-based diphosphine ligands that can catalyze highly chemo-, regio-, and stereoselective hydroboration reactions of unsymmetrical internal alkynes. These reactions exhibit unusual regioselectivity, leading to the synthesis of trisubstituted alkenylborates and alkenes with different stereochemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
A. Ziyaei Halimehjani, B. Breit
Summary: A rhodium-catalyzed hydrothiolation reaction of terminal allenes with thioacids has been developed for the synthesis of chiral branched allylic thioesters. The reaction exhibits excellent regio- and enantioselectivity and is applicable to the diastereoselective synthesis of thioesters from Fmoc-protected aminothioacids.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Chen Tan, Hongwu Jiang, Miao Zeng, Kaiwen Li, Zhuqi Chen, Guochuan Yin
Summary: This study presents a Pd(ii)/LA catalyzed indole olefination using dioxygen as the sole oxidant. The reaction proceeds smoothly with electron-rich olefins through remote C-H activation, while electron-deficient olefins follow a different pathway. Kinetic studies using H-1 NMR reveal a faster reaction rate for electron-rich olefins.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Physical
Feng Wang, Yuecong Guo, Yutong Zhang, Pingping Tang
Summary: The silver-catalyzed dibromotrifluoromethoxylation of terminal alkynes reported provides 1,1-dibromo-2-(trifluoromethoxy)alkenes in good yields and high regioselectivity under mild reaction conditions. The reaction has a broad substrate scope and can be used for late-stage trifluoromethoxylation of complex small molecules. The products can be further modified, offering a convenient method for synthesizing compounds containing the OCF3 group.
Article
Chemistry, Multidisciplinary
Yang Yuan, Youcan Zhang, Wenbo Li, Yanying Zhao, Xiao-Feng Wu
Summary: A novel method for constructing amide bonds through anti-Markovnikov hydroaminocarbonylation of unactivated alkenes has been developed. Copper catalysis, hydroxylamine electrophile reagents, and poly(methylhydrosiloxane) (PMHS) were used under mild conditions. The reaction showed a high degree of tolerance towards various functional groups and efficiently converted unactivated terminal alkenes, 1,1-disubstituted alkenes, and cyclic alkenes to the corresponding amides with exclusive anti-Markovnikov selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yang Yuan, Youcan Zhang, Wenbo Li, Yanying Zhao, Xiao-Feng Wu
Summary: This paper reports a general method for the anti-Markovnikov hydroaminocarbonylation of unactivated alkenes under mild conditions, using copper catalysis in combination with hydroxylamine electrophile reagents and poly(methylhydrosiloxane) (PMHS) as a cheap and environmentally friendly hydride source. The reaction tolerates a variety of functional groups and efficiently converts unactivated terminal alkenes, 1,1-disubstituted alkenes, and cyclic alkenes to the corresponding amides with exclusive anti-Markovnikov selectivity (and high enantioselectivities/diastereoselectivities). Additionally, with minimal modification of the reaction conditions, alkynes can also undergo tandem hydrogenation-hydroaminocarbonylation to alkyl amides.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Yidi Li, Huiying Xu, Lin Huang, Zhi Zhou, Zhenhao Tang, Haifang Meng, Wei Zhang, Wei Yi, Xiaowei Wu
Summary: We developed an efficient and regioselective method for the synthesis of trisubstituted 2-pyridone derivatives using a rhodium-catalyzed cascade reaction. This protocol offers several advantages, including a reusable catalytic system, high regioselectivity, uncommon Lossen rearrangement, good functional group tolerance, mild reaction conditions, simple purification, and scalability. The reaction mechanism was investigated through deuterium labeling, KIE assays, control experiments, and DFT calculations. The role of the hydroxyl group on propargyl alcohols in determining the regioselectivity was demonstrated, and the origin of the observed preference for the Lossen rearrangement was probed through Mulliken atomic charge analysis.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Muniganti Naveen Kumar, Vavilapalli Suresh, Attunuri Nagireddy, Jagadeesh Babu Nanubolu, Maddi Sridhar Reddy
Summary: Annulations of unsaturated systems through C-H activation are a powerful tool for producing multicyclic scaffolds. Employing a dual coordination strategy with coordinating centers in both annulation partners can lead to remarkable selectivities. In this study, we report a Pd-catalyzed regioselective rollover cascade dual C-H annulation for constructing phenanthrene scaffolds. Mechanism studies, including control experiments, KIE, and deuteration experiments, were conducted, and downstream transformations and scaled-up reactions were performed to evaluate the robustness of the transformation.
CHEMICAL COMMUNICATIONS
(2023)
