Article
Chemistry, Physical
Wen-Qian Zhang, Hong-Cheng Shen
Summary: All-carbon quaternary stereocenters are important components of natural products and bioactive compounds, and a nickel and chiral amine cooperative catalysis has been disclosed to enable highly enantioselective allylic alkylation reactions. This method allows for the synthesis of diverse compounds with excellent enantioselectivity, and has been demonstrated in the synthesis of key chiral building blocks for bioactive compounds such as (+)-eptazocine and (-)-aphanorphine.
Article
Chemistry, Physical
Xinyan Lv, Yaohang Cheng, Yingxiao Zong, Qingyun Wang, Guanghui An, Junke Wang, Guangming Li
Summary: In this study, a visible-light-mediated Ru-catalyzed para-alkylation of anilines was reported. The reaction showed high efficiency and mild conditions, with good functional group tolerance for late-stage functionalization of natural products and drugs.
Article
Chemistry, Physical
Fang Zhou, Shaolin Zhu
Summary: Here, a chiral selective nickel-hydride catalyzed hydroalkylation method is reported for the synthesis of structurally diverse beta-chiral amides from readily accessible beta-alkyl-alpha,beta-unsaturated amides. The regio-reversed hydronickellation process provides a complementary approach to access enantioenriched beta-functionalization amides with a stereocenter at the beta-position.
Article
Chemistry, Multidisciplinary
Changpeng Chen, Wenqing Guo, Deyong Qiao, Shaolin Zhu
Summary: We report a NiH-catalyzed asymmetric migratory hydroalkylation process for the efficient and selective construction of enantioenriched multi-substituted cycloalkanes. Through a dynamic kinetic asymmetric transformation (DYKAT), easily accessible racemic and isomeric mixtures of cycloalkenes could be directly utilized as starting materials, convergently producing highly regio-, diastereo-, and enantioselective chiral 1,2-cis disubstituted cycloalkanes. In addition, prochiral cyclic alkenes can also be employed, delivering chiral 1,2-cis disubstituted cycloalkanes through desymmetrization process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yun-Cheng Luo, Ming-Kuan Wang, Ling-Chao Yu, Xingang Zhang
Summary: Here, we report a nickel-catalyzed selective C(sp(2))-F bond alkylation of HFO-1234yf with alkylzinc reagents, resulting in 2-trifluoromethylalkenes that can serve as versatile synthons for diversified transformations. Mechanistic studies reveal that the addition of lithium salt is crucial for promoting the oxidative addition of Ni-0(L-n) to the C-F bond, and less electron-rich N-based ligands exhibit comparable or higher oxidative addition rates compared to electron-rich phosphine ligands.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Qian Zeng, Fengyun Gao, Jordi Benet-Buchholz, Arjan W. Kleij
Summary: A modular and practical method has been developed for the synthesis of complex allylic alcohols through a three-component reaction using dual photoredox/Ni catalysis. This method allows for high regio- and stereoselectivity and provides access to compounds with sterically congested and functionalized quaternary carbon centers. The stereoselectivity can be reversed by changing the photocatalyst.
Article
Chemistry, Organic
Yuto Shimazaki, Ayumi Osawa, Yoshiaki Nakao
Summary: In this study, we report a novel iridium/aluminum cooperative catalysis for the direct bridge-head C(sp(3))-H borylation. The reaction gives good yields with moderate to complete site selectivities and allows for the synthesis of enantioenriched alkylboronate products. The synthetic utility of the reaction is further demonstrated by rapid diversifications without any loss of the stereochemical information.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Manar M. Shoshani
Summary: The development of regioselective C-H functionalization methodologies for N-heterocycles has grown consistently in the past two decades. Cooperative reactivity resulting from the addition of Lewis-acidic metals to late-transition-metal complexes has enabled selective catalytic transformations. Advances in ligand design and Lewis-acidic metal precursors have led to the development of in situ cooperative catalysts capable of facilitating C-H functionalization at the C-2, C-3, and C-4 positions of pyridine. Recent efforts have targeted well-defined heterometallic complexes for C-H bond catalysis, achieving regioselective C-2 transformations. This perspective examines the evolution of strategies to enhance cooperative reactivity between Lewis-acidic metals and late transition metals in regioselective C-H functionalization, and discusses potential pathways for further enhancing modular regiodivergence in pyridine C-H bond catalysis.
CELL REPORTS PHYSICAL SCIENCE
(2023)
Article
Multidisciplinary Sciences
Yantao Li, Qianzhen Shao, Hengchi He, Chengjian Zhu, Xiao-Song Xue, Jin Xie
Summary: The authors present a method to synthesize tetrasubstituted olefins via dual photo- and nickel catalysis under an air atmosphere, without the need for an inert atmosphere. The synthesis of these compounds under mild conditions is challenging, but the authors were able to achieve it by using readily available carboxylic acids and alkenyl triflates. The method shows promise for applications in complex molecule modification and gram-scale synthesis.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Raymond F. Turro, Marco Brandstatter, Sarah E. Reisman
Summary: This study reports a method for the preparation of heterobenzylic amines through a Ni-catalyzed reductive cross-coupling reaction, which proceeds under mild conditions, avoids the pre-generation of organometallic reagents, and exhibits good functional group tolerance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Jian Chen, Lifu Wu, Yue Zhao, Shaolin Zhu
Summary: In this study, we report a catalytic reaction that can control two stereocenters simultaneously. By using a chiral catalyst, we achieved simultaneous control of the stereocenters in two substrates, resulting in the formation of high-value products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Shuai Li, Yu-Hua Wen, Jin Song, Liu-Zhu Gong
Summary: The combination of ruthenium catalysis and N-heterocyclic carbene (NHC) catalysis has successfully achieved asymmetric redox benzylation of enals, providing strategic opportunities for asymmetric benzylation reactions. A wide range of 3,3'-disubstituted oxindoles with a stereogenic quaternary carbon center, commonly found in natural products and biologically interesting molecules, were obtained with excellent enantioselectivities (up to 99% enantiomeric excess). This catalytic strategy also demonstrated its generality in late-stage functionalization of oxindole skeletons. The linear correlation between the ee values of the NHC precatalyst and the product elucidated the independent catalytic cycle of either the NHC catalyst or the ruthenium complex.
Article
Chemistry, Organic
Qiulin You, Xin Xiao, Yang Shi, Yimin Wu, Guangying Tan
Summary: Transition-metal-catalyzed directed C-H allylation of arenes is an efficient method to construct value-added allylic arenes. This study presents a novel iron catalyst and a chelation-induced strategy for the para-C-H allylation of aniline derivatives, which provides good yields and excellent selectivity.
Article
Chemistry, Organic
Qiulin You, Xin Xiao, Yang Shi, Yimin Wu, Guangying Tan
Summary: This study reveals a novel iron-catalyzed para-C-H allylation reaction of aniline derivatives via a chelation-induced strategy, providing various allylic arenes with good yields and selectivity.
Article
Chemistry, Multidisciplinary
Hui Wang, Wangyujing Han, Adam Noble, Varinder K. Aggarwal
Summary: This study reports a nickel/photoredox-catalyzed site-selective mono-deboronative arylation of 1,2-bis-boronic esters, which allows for selective coupling of the more sterically hindered secondary/tertiary positions. This is achieved by utilizing a 1,2-boron shift of primary β-boryl radicals to the thermodynamically favored secondary/tertiary radicals for arylation. The mild conditions of this method are suitable for a wide range of aryl halides, resulting in good yields and high regioselectivity. Additionally, this method allows for stereodivergent coupling of cyclic cis-1,2-bis-boronic esters to give trans-substituted products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Yoshiaki Nakao
Summary: Nitriles are versatile building blocks in organic synthesis, with common reactions including transformations of cyano groups. While the C-CN bond of nitriles is thermodynamically robust and rarely used as a reaction site, metal-catalyzed reactions have shown the potential for activation. These reactions are categorized into those using CN as a leaving group and those utilizing nitriles as a source of CN groups, offering new possibilities for organic synthesis.
Article
Chemistry, Multidisciplinary
Kazuhiko Semba, Naoki Ohta, Fritz Paulus, Masaki Ohata, Yoshiaki Nakao
Summary: This new method allows for allylarylation of electron-deficient alkenes using aryl boronates and allylic carbonates as starting materials, leading to a variety of carbon skeletons. Mechanistic studies reveal that the reaction is facilitated by a cooperative catalysis involving Pd-0/Pd-II redox and Pd-II/Pd-II non-redox catalytic cycles.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Naofumi Hara, Konosuke Yamamoto, Yuuki Tanaka, Teruhiko Saito, Shigeyoshi Sakaki, Yoshiaki Nakao
Summary: In this study, rhodium complexes with X-type PBP and PGaP pincer ligands were synthesized, showing that the sigma-donicity and trans-influence of the X-type boryl ligand are stronger than those of the X-type gallyl ligand. The Lewis acidity of the PEP-Rh complexes (E = B, Al, Ga) was examined, with experimental and computational results indicating that the Lewis acidity increases in the order B (1) < Ga < Al.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2021)
Article
Chemistry, Multidisciplinary
Rin Seki, Naofumi Hara, Teruhiko Saito, Yoshiaki Nakao
Summary: In this study, we reported a novel rhodium catalyst with X-type PAlP pincer ligand for catalytic reduction of a C-O bond and borylation. The reaction mechanism was revealed through characterization of reaction intermediate and deuterium-labeling experiments. This catalytic system demonstrated steric-hindrance-dependent chemoselectivity, providing a new strategy for selective C-O bond activation through heterobimetallic catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Kazuhiko Semba, Yasuhiro Ohtagaki, Yoshiaki Nakao
Summary: A method for 1,2-arylboration of aliphatic alkenes to afford alkylboronic esters through cooperative palladium/copper catalysis was developed, showing high regioselectivity and tolerance to various functional groups under the reaction conditions.
TETRAHEDRON LETTERS
(2021)
Review
Chemistry, Multidisciplinary
Myuto Kashihara, Yoshiaki Nakao
Summary: Cross-coupling reactions using nitroarenes as electrophiles have gained attention due to their ease of accessibility and potential advantages over haloarenes. Recent research has focused on developing new catalyst systems and reaction conditions to improve the efficiency and practicality of these reactions, with promising results in diversifying bond-forming reactions and reducing catalyst loading. Research in this field is expected to continue growing as the utility of nitroarenes in organic synthesis is reevaluated.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Article
Chemistry, Inorganic & Nuclear
Naoki Matsushita, Myuto Kashihara, Michele Formica, Yoshiaki Nakao
Summary: Through the use of a new designed ligand, Pd-catalyzed etherification of nitroarenes with arenols was achieved, allowing for the direct access to a range of unsymmetrical diaryl ethers. The design of the ligand facilitated both the oxidative addition and reductive elimination steps of the catalytic cycle, providing mechanistic insights for optimizing the reaction.
Article
Chemistry, Organic
Naofumi Hara, Koki Aso, Qiao-Zhi Li, Shigeyoshi Sakaki, Yoshiaki Nakao
Summary: This study reports a C2-and mono-selective alkylation of various pyridines and azines with unactivated alkenes and vinylarenes using a heterobimetallic Rh-Al catalyst. Experimental results show that the use of aliphatic alkenes exclusively affords linear alkylation products, while vinylarenes mainly afford branched alkylation products. The details of the reaction mechanism, revealed by DFT calculations, indicate that the reductive elimination of the products is rate-determining, consistent with experimental results. The origin of the linear/branched selectivity is elucidated based on deformation/interaction analysis.
Article
Chemistry, Applied
Qiao-Zhi Li, Naofumi Hara, Kazuhiko Semba, Yoshiaki Nakao, Shigeyoshi Sakaki
Summary: Rh(PAlP) is a new type of catalyst for reactions via sigma-bond activation, showing unique Rh-Al direct bond, flexible substrate coordination, and new catalytic functions for C-H and C-F sigma-bond activations. The unusual Rh delta--Al delta+ polarization and coordination flexibility play important roles in these catalytic reactions.
TOPICS IN CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Kazuhiko Semba, Fumiya Shimoura, Yoshiaki Nakao
Summary: A cobalt complex ligated with a PAlP pincer ligand was synthesized and the Lewis acidity of the aluminum atom on the cobalt complex was confirmed by coordination with 4-dimethylaminopyridine (DMAP). Reactions of the cobalt complex with H2O, EtOH, i-PrOH, and t-BuOH efficiently yielded the corresponding cobalt hydride complexes.
Article
Chemistry, Physical
Naofumi Hara, Kazuhiko Semba, Yoshiaki Nakao
Summary: Transition metal complexes with X-type aluminyl ligands exhibit strong reactivity and enable various challenging catalytic transformations such as transfer dehydrogenation, highly efficient CO2 reduction, and site-selective C-H bond functionalization.
Article
Chemistry, Organic
Ikuya Fujii, Kazuhiko Semba, Yoshiaki Nakao
Summary: Rhodium-aluminum bimetallic complexes catalyze the Kumada-Tamao-Corriu (KTC) cross-coupling reaction using arylmagnesium compounds generated from corresponding aryl fluorides or chlorides. This method allows the challenging KTC coupling reaction to be carried out using aryl fluorides as nucleophiles, resulting in various biaryls.
Review
Chemistry, Organic
Yoshiaki Nakao
Summary: C-H functionalization is a key technique in organic synthesis to simplify chemical processes by converting unfunctionalized C-H bonds into functional groups. Traditionally, functionalization required pre-functionalized compounds, but now direct transformation is possible. However, current strategies using directing groups and additional steps limit efficiency, while a new approach utilizing Lewis acid-base formations to control site-selectivity of functionalization is being explored.
JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN
(2021)
Article
Chemistry, Multidisciplinary
Naofumi Hara, Nao Uemura, Yoshiaki Nakao
Summary: A C2-selective mono-silylation of various pyridines has been developed using a Rh-Al complex, where the site- and mono-selectivity are controlled by the coordination of pyridine to the Lewis-acidic Al center. A reaction mechanism is proposed based on the isolation of a (2-pyridyl)silylrhodium intermediate from several mechanistic studies.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Kitty K. Asahara, Myuto Kashihara, Kei Muto, Yoshiaki Nakao, Junichiro Yamaguchi
Summary: The activation of Ar-NO2 bonds by Pd/BrettPhos catalyst has enabled denitrative couplings, overcoming the bottleneck of general denitrative transformations. Deep understanding of the reaction mechanism also led to the design of a more active Pd/NHC system.
JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN
(2021)
