Article
Chemistry, Organic
Milauni M. Mehta, Jordan A. M. Gonzalez, James L. Bachman, Neil K. Garg
Summary: We present a method for constructing the core structure of the manzamine alkaloid keramaphidin B using a strain-promoted cycloaddition reaction. This method tolerates nitrile and primary amide functional groups, and can be followed by a retro-Diels-Alder reaction to increase structural complexity. These findings highlight the potential of strained cyclic allenes in building intricate structures, and provide inspiration for further studies on these transient intermediates.
Article
Chemistry, Organic
Casper Larsen Barlose, Jonas Faghtmann, Rene Slot Bitsch, Joseph Daniel Gbubele, Karl Anker Jorgensen
Summary: The combination of asymmetric organocatalysis with the (pseudo)-halogen effect allows for the efficient formation of chiral norcarane scaffolds. These scaffolds can easily undergo rearrangements or lactonization to form intricate chiral ring structures.
Article
Chemistry, Organic
Jian-Xiang Zhu, Fu Pi, Teng Sun, Wen-Yu Huang, Lu Gao, Zhi-Chao Chen, Wei Du, Ying-Chun Chen
Summary: This article introduces a palladium-catalyzed tandem reaction that proceeds through sequential 2,4-dienylation/Michael addition/pi-sigma-pi isomerization/allylic alkylation. Using ortho-functionalized aryl enones and 2,4-dienyl carbonates as substrates, enantioenriched architectures with fused and spirocyclic frameworks are constructed in moderate to excellent yields and stereoselectivity. Importantly, the intrinsic intramolecular Diels-Alder reaction pattern of the dienylated intermediates is effectively reversed via Pd(0)-pi-Lewis base catalysis.
Article
Chemistry, Organic
Matteo Lanzi, Racha Abed Ali Abdine, Maxime De Abreu, Joanna Wencel-Delord
Summary: This study reported the synthesis of dissymetric 2,3,2',3',4-substituted biaryls via pericyclic reactions of cyclic diaryl lambda(3)-bromanes. The method provides functional group tolerance and atom economy, allowing access to molecular complexity in a single reaction step. Continuous flow protocol has been designed for scale-up, while postfunctionalizations have been developed leveraging the residual Br-atom.
Article
Chemistry, Organic
Bhavani Shankar Chinta, Daniel Lee, Thomas R. Hoye
Summary: This study reports a successful reaction of benzynes generated by hexadehydro-Diels-Alder reaction with coumarin to produce phenanthrene derivatives, highlighting the reactivity difference between 2-pyrone and coumarin.
Article
Biochemistry & Molecular Biology
Michal Michalski, Slawomir Berski
Summary: The electronic structure and reactivity of 22 isorhodanine derivatives in the Diels-Alder reaction were studied under two different environments using various methods. The results showed both inverse electronic demand and normal electronic demand characteristics in the reaction and provided insights into the aromaticity of the isorhodanine ring. Additionally, the study demonstrated the potential of electron localization function analysis to capture chemical reactivity and provide valuable insights into the electronic structure of molecules.
Article
Chemistry, Organic
Yuchen Du, Joel T. Mague, Robert A. Pascal
Summary: Highly congested derivatives of biphenyl were prepared through double Diels-Alder reactions, sometimes resulting in only one addition and in other cases leading to two additions. The structures of the compounds showed crowding but without the distortions seen in previous observations.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Guang-Chao Feng, Jun-Chi Li, Xiang Huang, Ji-Kai Liu, Bin Wu, Jin-Ming Yang
Summary: A novel cascade gold(I)-catalyzed hydroarylation of alkynylindoles and subsequent Diels-Alder cycloaddition with electron-deficient alkynes and alkenes is reported herein. The method features low catalyst loadings, high regioselectivity, broad functional group tolerances, access to important heterocycles, and 100% atom economy.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Yan Jiang, Hao-Jie Ma, Xue-Long Wang, Yi Yang
Summary: A new compound was synthesized successfully in this study by using Yb-(OTf)(3) catalyst to react donor-acceptor cyclopropanes with sulfur-containing 4π components. The reaction showed high yields and moderate to good diastereoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Kailas V. Preeti, Kailas V. Kallurkar, Prathama S. Mainkar, Raju Adepu, Srivari Chandrasekhar
Summary: A concise route for the synthesis of dihydrobenzo-[j]-phenanthridinones has been developed using an aryne annulation strategy under metal-free reaction conditions. The reaction involves multiple C-C and C-N bond cleavages/formations through Diels-Alder reaction, aromatization-driven C-N bond cleavage, and amide formation.
Article
Chemistry, Organic
Hongling Wang, Qiangqiang Zhang, Shuai Xiao, Guanjie Wang, Xuan Huang, Xingkuan Chen, Junmin Zhang
Summary: We have developed a N-heterocyclic carbene (NHC) and base-mediated [3 + 3] annulation reaction for the synthesis of enantioselective dihydropyrano[3,2-b]indoles. Easily prepared sulfonium salts were used as precursors and reacted with unsaturated acyl azolium to achieve this transformation. The reaction conditions are mild and result in privileged indole-fused dihydropyranones with moderate to good yields and excellent enantioselectivities.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Yajuan Zhang, Jie Dong, Yu Lei, Lingli Zong, Ke Zhang, Yimin Hu
Summary: Highly regioselective ferrocenyl cyclohexene/cyclopentene isomerization is achieved through hexadehydro-Diels-Alder (HDDA) benzyne transfer coupling. The reaction proceeds under mild conditions without a catalyst, with tetraynes forming aryne intermediates that are then trapped by ferrocene-tethered cyclohexene/cyclopentene. Density functional theory (DFT) calculations reveal that the key step in the process is the Alder-ene reaction, which allows for the synthesis of functionalized ferrocene derivatives with high regioselectivity and excellent yields. This study expands the coupling reaction between arynes and cyclic alkenes, providing an innovative approach for the synthesis of ferrocene derivatives.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Huy Tran, Guillaume Revol, Alyson Poyser, Louis Barriault
Summary: In this study, a novel Lewis acid gold catalyst was used to generate synthetically challenging polycyclic scaffolds through a one-pot cascade sequence. By controlling the ligand and reaction conditions, both 6,6,5-tricyclic and 6,6,6,5-tetracyclic cores were selectively synthesized in one operation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Eveline H. Tiekink, Pascal Vermeeren, Trevor A. Hamlin
Summary: Tropone is unreactive in normal electron-demand Diels-Alder reactions, but can be activated by using hydrazone ion analogs for carbonyl umpolung. Previous research attributed the higher reactivity of hydrazone ion analogs to raised HOMO energy induced by antiaromaticity. However, this study proves that the activation barrier is actually lowered by increased asynchronicity.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Nikolay Shcherbakov, Elena Chikunova, Dmitry Dar'in, Vadim Yu Kukushkin, Alexey Yu Dubovtsev
Summary: The Gold(I)-catalyzed [4 + 2] cycloaddition of indolylynamides and cyanamides is an efficient method for the synthesis of diversely substituted 1,3-diamino-beta-carbolines. This protocol is mild and tolerant to functional groups, allowing for successive functionalizations. Control experiments reveal the importance of reactant nature and catalyst identity in this developed cycloaddition.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
