Article
Chemistry, Multidisciplinary
Bo-Han Zhu, Sheng-Bing Ye, Min-Ling Nie, Zhong-Yang Xie, Yi-Bo Wang, Peng-Cheng Qian, Qing Sun, Long-Wu Ye, Long Li
Summary: In this study, an unprecedented I-2-catalyzed cycloisomerization of ynamides is developed, leading to the synthesis of various functionalized bis(indole) derivatives in good to excellent yields. This reaction represents the first molecular-iodine-catalyzed tandem complex alkyne cycloisomerizations and a chemoselective cycloisomerization of tryptamine-ynamides involving distinct C(sp(3))-C(sp(3)) bond cleavage and rearrangement. Chiral tetrahydropyridine frameworks containing two stereocenters are also obtained with moderate to excellent diastereoselectivities and enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yun-Xuan Tan, Pei-Ying Peng, Ya-Jie Wang, Xi-Liang Liu, Wenbo Ye, Dingding Gao, Guo-Qiang Lin, Ping Tian
Summary: This study reports a diastereo- and enantioselective rhodium(iii)-catalyzed reductive cyclization of cyclohexadienone-tethered terminal alkenes and (E)-1,2-disubstituted alkenes, resulting in cis-bicyclic products with three contiguous stereocenters in good yields and high selectivities. The kinetic resolution of the racemic precursor is also achieved efficiently, along with subgram-scale experiment, several transformations of the cyclization product, and one-pot preparation of bridged polycyclic frameworks.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Frederik Kramm, Franziska Ullwer, Benedict Klinnert, Min Zheng, Bernd Plietker
Summary: We present an unusual cyclopropyl enyne cycloisomerization that activates C-C bonds in cyclopropanes, leading to the synthesis of substituted non-canonical tricyclic cyclobutanes with high stereocontrol using [(Ph3P)(2)Fe(CO)(NO)]BF4 as catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Rakesh K. Saunthwal, Kapil Mohan Saini, Nicolas Grimblat, Abhinandan K. Danodia, Sushil Kumar, Vincent Gandon, Akhilesh K. Verma
Summary: We describe an unconventional approach for the synthesis of highly decorated polyaromatic biaryls with excellent regioselectivity through site-selective Ag-catalyzed twofold electrophilic cycloisomerization followed by Au-catalyzed double C-H activation. DFT computations reveal that this reaction represents a rare example of C1-C5 endo-exo and C1-C6 endo-endo cycloaromatization, with the formation of the 6-membered ring predicted to be the result of an uncommon SEAr on a vinyl carbocation.
Article
Chemistry, Organic
Yi Chen, Di Liu, Rui Wang, Li Xu, Jingyao Tan, Mao Shu, Lingfeng Tian, Yuan Jin, Xiaoke Zhang, Zhihua Lin
Summary: This study presents a synthetic protocol for constructing a valuable polycycle scaffold through CCOM using inexpensive, non-toxic phosphomolybdic acid as a catalyst, featuring mild reaction conditions, simple manipulation, and scalability. This strategy provides a promising alternative to Lewis acid-catalyzed COM reaction for realizing carbonyl-olefin, carbonyl-alcohol, and acetal-alcohol in situ CCOM reactions.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ren-Xiao Liang, Ling-Jie Song, Jin-Bo Lu, Wei-Yan Xu, Chao Ding, Yi-Xia Jia
Summary: The study presents a PdH-catalyzed enantioselective heteroarenyne cycloisomerization reaction and a classical enantioselective 1,5-enyne cycloisomerization of N-vinylpropiolamides, showcasing the synthesis of diverse chiral spiro and fused indoline derivatives as well as chiral 2-pyrrolones with good to excellent enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Tanmay Malakar, Paul M. Zimmerman
Summary: In this study, it was found that Brønsted acid (such as triflic acid) differs from Lewis acid in promoting the carbonyl-olefin metathesis by invoking a mechanistic switch to a carbonyl-ene reaction, where oxygen-atom transfer is found to be uncompetitive. Additionally, the conjugate base of TfOH is able to rearrange H atoms and allow isomerization of the carbocations that appear after the carbonyl-ene reaction, providing insights into the mechanism of activation of intramolecular carbonyl-olefin substrates by Brønsted acids.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Romeric Galea, Gaelle Blond
Summary: In this study, [7,5]-fused bicyclic acetals, also known as furooxepines, were synthesized through a gold(I)-catalyzed domino reaction. This one-step reaction allows the formation of multiple bonds, heterocycles, and a tetrasubstituted carbon stereocenter with 100% atom economy.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Yuki Umakoshi, Kazushige Wakisaka, Akira Tsubouchi, Akira Yoshimura, Akio Saito
Summary: This article reports a new method for the construction of a cyclic skeleton concomitant with the introduction of a functional group through a tandem reaction. This method does not require prefunctionalization of the coupling partner, making it greener.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Veronique Michelet
Summary: The field of gold catalysis has been expanding continuously over the past 20 years, with the discovery of several new rearrangements. Key contributions in this area include the pi-activation of unsaturated substrates and the application of aryl, alkyne, alkene, or keto derivatives.
Article
Chemistry, Physical
Logan E. Vine, Ryan D. Reeves, Eleanor M. Landwehr, Israel Fernandez, Jennifer M. Schomaker
Summary: This study demonstrates predictable control over the mechanism of Pd-catalyzed allene cross-coupling/cyclization and cycloisomerization by targeted changes to the reaction conditions, resulting in the successful access to enantioenriched cyclopropanes and cyclopentenes. Furthermore, it shows a simple switch of the ligand on Pd can divert the reactivity of allenyl malonate from cross-coupling/cyclization to cycloisomerization.
Article
Chemistry, Organic
Linglong Ding, Yi-Hui Deng, Tian-Yu Sun, Yuqin Jiang, Xiao-Feng Xia
Summary: This article describes the development of a metal-free iodide-catalyzed radical reductive cyclization of 1,6-enynes. A strategy involving in situ iodination/radical cyclization/silyl radical-mediated halogen atom transfer/hydrogen atom transfer for the synthesis of functionalized pyrrolidines has been proposed. Using this halogen-atom abstraction protocol, 1,6-enynes with various vinyl halides including inert fluorides, chlorides, and reactive bromides could be transformed into substituted pyrroles through a multistep radical isomerization process.
Article
Chemistry, Organic
Fabio Seoane-Carabel, Lorena Alonso-Maranon, Luis A. Sarandeses, Jose Perez Sestelo
Summary: 1H-isochromenes and 1,2-dihydroisoquinolines are synthesized through regioselective intramolecular hydrofunctionalization of o-(alkynyl)benzyl derivatives catalyzed by indium(III). The reaction with o-(alkynyl)benzyl alcohols and amines results in regioselective 6-endo-dig intra-molecular alkyne hydroalkoxylation or hydroamination in good yields using indium triiodide. Alternatively, the cycloisomerization reaction of o-(alkynyl)benzaldehydes and imine derivatives using InI3 and the Hantzsch ester gives a variety of functionalized 1H-isochromenes and 1,2-dihydroisoquinolines through a domino cycloisomerization/reduction approach.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Shashank Shandilya, Manash Protim Gogoi, Shubham Dutta, Akhila K. Sahoo
Summary: Ynamide, a unique species with inherited polarization of nitrogen lone pair electron to triple bond, has been widely used for the development of novel synthetic methods and the construction of unusual N-bearing heterocycles. This review provides an overall scenic view into the gold catalyzed transformation of ynamides, including their reactivity towards various transfer reagents and carbon nucleophiles.
Article
Chemistry, Organic
Xia Chen, Zengwei Luo, Yong Chen, Yonghui Zhang
Summary: A simple and efficient catalytic reaction for the synthesis of valuable functionalized compounds has been developed. The reaction proceeds in one step under environmentally friendly conditions and has shown excellent yields. The study also revealed the involvement of an unconventional intermediate in the reaction mechanism.
