Review
Chemistry, Physical
Ximei Zhao, Guanghui Wang, A. Stephen K. Hashmi
Summary: Carbene B-H insertion reactions, including free and metal carbene insertion into B-H bonds, have made significant advances in recent years. The development of this chemistry complements existing C-B bond formation strategies in terms of substrate scope, selectivity, and product diversity. Notably, catalytic enantioselective carbene B-H insertion reactions enable easy access to important chiral organoboron compounds.
Review
Chemistry, Organic
Douglass F. Taber
Summary: Direct functionalization of unactivated C-H bonds is becoming increasingly important in organic synthesis. Among the various methods, intramolecular alkylidene C-H insertion, which retains the absolute configuration, is one of the most versatile. This Review explores all examples of the use of intramolecular alkylidene C-H insertion in natural product synthesis.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ziyong Li, Ying Chen, Chuang Wang, Guangyang Xu, Ying Shao, Xinhao Zhang, Shengbiao Tang, Jiangtao Sun
Summary: The atroposelective synthesis of biaryl atropisomers via asymmetric C(sp(2))-H bond insertion reaction of arenes under rhodium catalysis has been achieved, providing moderate to excellent yields with good enantiomeric ratios. Further investigation suggests that this type of axially biaryl scaffold may have promising potentials in developing novel chiral ligands.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Bo Liu, Ming-Hua Xu
Summary: This study presents a new version of asymmetric carbene C-H insertion reaction using a rhodium(I) catalyst and chiral ligand, enabling efficient synthesis of a variety of chiral products at room temperature with excellent enantioselectivities. The synthetic utility of this method is demonstrated through the facile synthesis of a novel cannabinoid CB1 receptor ligand, suggesting potential for the development of therapeutically exploitable cannabinoid receptor type ligands in medicinal chemistry.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Applied
Juan Diego Pizarro, Lucia Moran-Gonzalez, Ivan Gonzalez-Fernandez, Feliu Maseras, Manuel R. Fructos, Pedro J. Perez
Summary: Copper catalysts containing ADAP ligand selectively functionalize unprotected indoles at the C3-H position through carbene transfer, without altering the N-H bond. Mechanistic studies, including DFT calculations, propose two competitive pathways that do not involve the formation of cyclopropane intermediates, contrasting with previous reports.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Benjamin D. Bergstrom, Amy T. Merrill, James C. Fettinger, Dean J. Tantillo, Jared T. Shaw
Summary: This article reports the first synthesis methods of Panowamycins and their epimers, and reveals the previous structural misassignment of panowamycin A and veramycin F. The researchers achieved these synthesis methods through dirhodium-catalyzed C-H insertion reactions and Wacker oxidation, avoiding the use of protecting groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Zilong Huang, Jie Lin, Juan Ma, Liandi Wang, Yong-Gui Zhou, Zhengkun Yu
Summary: Carbene insertion into C(sp(2))-H bonds of internal alkenes was achieved in air using HFIP as both the mediator and solvent, along with borane B(C6F5)(3) as the catalyst. The reaction showed high yields (47-84%) and broad substituent tolerance, providing an efficient route to synthesize 3-vinylated oxindole and indole derivatives.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Zhen Liu, Zi-Yang Qin, Ledong Zhu, Soumitra Athavale, Arkajyoti Sengupta, Zhi-Jun Jia, Marc Garcia-Borras, K. N. Houk, Frances H. Arnold
Summary: Propargyl amines are versatile synthetic intermediates with numerous applications in the pharmaceutical industry. An enzymatic platform for enantioselective propargylic amination of alkynes using a hydroxylamine derivative as the nitrene precursor was developed in this study. The biocatalytic process showed high efficiency and selectivity, making it a promising approach for industrial applications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Lei Gao, Sheng Liu, Zi-Chao Wang, Yongjun Mao, Shi-Liang Shi
Summary: The study presents a ligand- and additive-free CuCl2-catalyzed highly selective para-C-H carbene insertion reaction, which can produce a variety of 1,1-diarylacetates with high yields and excellent selectivity.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jingfeng Huo, Kangbao Zhong, Yazhen Xue, MyeeMay Lyu, Yifan Ping, Wenbai Ouyang, Zhenxing Liu, Yu Lan, Jianbo Wang
Summary: In this study, a highly efficient palladium-catalyzed carbene insertion reaction into strained Si-C bonds of benzosilacyclobutanes was reported, providing an efficient method for accessing alpha-chiral silanes. It was found that with a sterically hindered ligand, the carbene insertion occurred selectively on the C(sp(3))-Si bond of benzosilacyclobutanes with excellent site- and enantioselectivity, while selectively occurred on the C(sp(2))-Si bond with less sterically hindered ligands. The reaction mechanism, particularly the roles of chiral ligands in controlling the site-selectivity of the insertion reactions, was elucidated using hybrid density functional theory.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Alex Diaz-Jimenez, Roger Monreal-Corona, Albert Poater, Maria Alvarez, Elena Borrego, Pedro J. Perez, Ana Caballero, Anna Roglans, Anna Pla-Quintana
Summary: The trapping of the elusive vinylogous position of a vinyl carbene with an aliphatic C(sp(3))-H bond has been achieved for the first time during a silver-catalyzed carbene/alkyne metathesis (CAM) process, leading to the synthesis of a new family of benzoazepines.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Yajun Li, Hongli Bao
Summary: This article discusses recent advances in the synthesis of allenes via radical intermediates, categorizing them into different types of substrates and distinct catalytic systems. Mechanistic studies and synthetic challenges are highlighted.
Article
Chemistry, Multidisciplinary
Mahesh S. Harariya, Romin Gogoi, Anubhav Goswami, Akhilesh K. Sharma, Garima Jindal
Summary: The mechanism of Rh2(S-NTTL)4 catalyzed carbene insertion into C(3)-H of indole is investigated using DFT methods. It is found that the enol pathway, which was previously considered to be of lower energy, can actually explain the enantioinduction. A new water-promoted mechanistic pathway involving metal-associated enol intermediate and stereochemical model is proposed to solve the conundrum. The importance of substrate-catalyst binding and water-assisted proton transfer in achieving high levels of enantioselectivity is demonstrated.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Qiao Ren, Tingting Cao, Chunnian He, Meihua Yang, Haitao Liu, Lei Wang
Summary: The highly atroposelective construction of axially chiral N-arylindolocarbazoles via Rh(II)-catalyzed intermolecular carbene N-H insertion reactions provides a rapid access to enantio-enriched products with moderate to good yields and high enantioselectivities. The synthetic utility of this method is emphasized by late-stage functionalization of representative natural products and bioactive molecules, as well as polyaromatic ring construction and chiral phosphoric acid synthesis from N-arylindolocarbazoles, highlighting its practical value in materials chemistry and catalytic asymmetric synthesis.
Article
Chemistry, Physical
Xinyu Zhang, Paramasivam Sivaguru, Giuseppe Zanoni, Xinyue Han, Minghui Tong, Xihe Bi
Summary: This study reports a novel enantioselective synthesis method, which enables the efficient synthesis of chiral fluoroalkyl derivatives by using fluoroalkyl N-triftosylhydrazones as the carbene source under mild conditions.