Article
Chemistry, Organic
Shangyuan Wang, Jiajun Zhao, Jun Ying, Xiao-Feng Wu
Summary: This study developed a palladium-catalyzed one-pot two-step radical mediated carbonylative cyclization method to construct polycyclic 3,4-dihydroquinolin-2-(1H)-one scaffolds using perfluoroalkyl iodides and Mo-(CO)(6) with 1,7-enynes. Various polycyclic 3,4-dihydroquinolin-2-(1H)-one derivatives containing perfluoroalkyl and carbonyl units were synthesized with high yields. Moreover, modification of several bioactive molecules was demonstrated using this protocol.
Article
Chemistry, Multidisciplinary
Tianmei Zhang, Min Cai, Wenfeng Zhao, Mao Liu, Nan Jiang, Qingmei Ge, Hang Cong
Summary: We developed a practical and efficient electrochemical approach for the synthesis of pi-conjugated phosphonium salts through intramolecular annulation and C-P bond construction. This reaction took place under catalyst- and adscititious oxidant-free conditions at room temperature. A variety of substituted pi-conjugated phosphonium salt products were obtained with good functional group tolerance and yields. A gram-scale reaction demonstrated the potential of this protocol for practical applications. Preliminary mechanistic studies suggested the involvement of free radicals in this process.
Article
Chemistry, Organic
Zhidong Jiang, Jianhui Zhou, Haoran Zhu, Hong Liu, Yu Zhou
Summary: A novel Rh(III)-catalyzed C-H activation/annulation cascade of indole-enaminones with diazo compounds was reported, generating diversely functionalized carbazole frameworks with good to excellent yields. The most notable feature is the formation of a novel [5 + 1] cyclization product, accompanied by the complete removal of acetyl and N,N-dimethyl groups from the substrates, rather than the expected [4 + 2] cyclization products.
Article
Chemistry, Organic
Demao Chen, Liyun Zhou, Chengping Wen, Jie-Ping Wan
Summary: By using readily available enaminones, aryl hydrazine hydrochlorides, and alkynes, a chemo-selective three-component synthesis of atropisomeric N-(o-alkenylaryl)pyrazoles was efficiently achieved with rhodium catalysis. Unlike the Satoh-Miura reaction, which uses pre-prepared N-phenyl pyrazoles and alkynes as substrates for alkyne-based C-H benzannulation, this three-component protocol demonstrates unprecedented selectivity of C-H alkenylation by blocking the second round metal alkenylation with the key protonation step in the presence of acids.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zhi-Kai Liu, Ying Yang, Zhuang-Ping Zhan
Summary: A general and efficient palladium-catalyzed hydroalkynylation method has been developed for the synthesis of (E)-1,3-enyne derivatives with high regio- and stereoselectivity. This method is compatible with a broad range of substrates and expands the synthetic potential of these scaffolds in organic synthesis and medicinal chemistry.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Attunuri Nagireddy, Dattatri, Ramesh Kotipalli, Jagadeesh Babu Nanubolu, Maddi Sridhar Reddy
Summary: This research presents a rhodium-catalyzed oxidative three-point double annulation of enaminones with propargylic alcohols to access arylnaphthalene-based lignan derivatives. The key step involves the regioselective insertion of propargylic alcohol into the rhoda-cycle due to hydroxyl rhodium coordination, with mechanism determined through control experiments and KIE studies.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Hongyu Guo, Sheng Zhang, Xiujuan Feng, Xiaoqiang Yu, Yoshinori Yamamoto, Ming Bao
Summary: A palladium-catalyzed cycloisomerization of 2-ethynylbiaryls to 9-methylidenefluorenes is described for the first time. This method is operationally simple and scalable, and exhibits high functional group tolerance.
Article
Chemistry, Physical
Bo-Han Zhu, Ying-Qi Zhang, Hao-Jin Xu, Long Li, Guo-Cheng Deng, Peng-Cheng Qian, Chao Deng, Long-Wu Ye
Summary: An efficient copper-catalyzed tandem alkyne hydration/intramolecular Mannich reaction has been investigated for the synthesis of valuable compounds. This method allows the efficient synthesis of 3,4-dihydro-2-quinolones with high regio-, diastereo-, and enantioselectivity.
Article
Chemistry, Multidisciplinary
Qiqiang Xie, Guangbin Dong
Summary: Boron-homologation reactions offer an efficient and programmable method for the synthesis of alkylboronates, providing valuable and versatile synthetic intermediates. By implementing aza-Matteson reactions, selective mono- and double-methylene insertions can be achieved, allowing access to various alpha- and beta-boron-substituted tertiary amines. Additionally, derivatization of complex amine-containing bioactive molecules, diverse functionalization of boronate products, and sequential insertions of different carbenoids have all been successfully demonstrated.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Zhenfeng Cheng, Xiaodong Qiu, Biao Xiong, Yanan Zhang, Xiaobao Zeng
Summary: This study presents a TMSCN-enabled tandem reaction involving enamides and elemental selenium to access a diverse array of benzoselenophenes. The protocol offers several noteworthy features, including the absence of transition metals and strong oxidants, high reaction efficiency, broad substrate scopes, and the use of stable elemental selenium as a selenium source.
Article
Chemistry, Organic
Yaowen Liu, Chunyu Han, Hongwei Shi, Alexandra V. Mackenroth, Linghua Zhang, Matthias Rudolph, Frank Rominger, A. Stephen K. Hashmi
Summary: A gold-catalyzed acyloxyalkynylation reaction was used to synthesize tetra-substituted enol ester 2-iodobenzoate derivatives in good yields at room temperature. The reaction is highly regioselective and can be easily scaled up to gram scale. Mechanistically, an Au(III) species plays a key role in an Au(I)/Au(III) redox cycle.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yong He, Hao Wang, Yao Zhou, Kai Yang, Qiuling Song
Summary: We report the highly regioselective synthesis of 5- and 4-(2,1-azaborine) substituted isoxazoles via [3 + 2] cycloaddition reactions between nitrile oxides and B-ethynyl-1,2-azaborines. 5-(2,1-azaborine) substituted isoxazoles are favored in the absence of a catalyst, while 4-(2,1-azaborine) substituted isoxazoles are favored in the presence of a ruthenium catalyst. The reaction exhibits excellent regioselectivity, mild reaction conditions, high functional group tolerance and a broad substrate scope.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Kunlayanee Punjajom, Sureeporn Ruengsangtongkul, Jumreang Tummatorn, Praneet Paiboonsombat, Somsak Ruchirawat, Charnsak Thongsornkleeb
Summary: A general protocol for oxidative annulation was developed to prepare 2-methyl-3,4-diacylquinolines directly from 2-alkynylanilines and 1,3-ketoesters. The reactions were mediated by Mn(OAc)3 in acetic acid at room temperature, leading to the desired quinoline products in one-pot in low to good overall yields on a wide range of substrates. The current method is convenient, conducted under mild conditions, and has short reaction times.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Jun Ma, Qijie Zou, Chunhua Wang, Guangwei Yin, Fangyi Li
Summary: In this study, a base promoted dibromination of enamides using CBr4 as a bromine source was reported, providing expedient access to beta,beta-dibrominated secondary enamides. The synthetic application study showed that these novel products can be readily transformed to 5-Br oxazoles via Cu(I) catalyzed intramolecular cyclization in good yields.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Raffaele Senatore, Monika Malik, Thierry Langer, Wolfgang Holzer, Vittorio Pace
Summary: The study reports a formal CH2-CH2 homologation conducted with C1 carbenoids on a carbon electrophile for the obtainment of a four-membered cycle, resulting in the assembling of a rare imino-thietane cluster. The double homologation protocol demonstrates genuine chemocontrol and is accomplished directly on a carbon electrophile without the need for heteroatom-centered manifolds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
