Article
Chemistry, Multidisciplinary
Wenxuan Xu, Xuefeng Cong, Kun An, Shao-Jie Lou, Zhenghua Li, Masayoshi Nishiura, Tetsuro Murahashi, Zhaomin Hou
Summary: In this study, the intermolecular regio- and diastereoselective formal [2+2] cycloaddition of allenes with amino-functionalized alkenes was achieved using half-sandwich rare-earth catalysts. The reaction proceeded through an allene C(sp(2))-H activation mechanism, leading to the synthesis of a new family of cyclobutane and cyclobutene derivatives.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Masahiro Murakami, Naoki Ishida
Summary: This article reviews synthetic transformations involving the cleavage of a carbon-carbon bond of a four-membered ring from 2011 to 2019, with a particular focus on progress in catalytic reactions such as oxidative addition and beta-carbon elimination, as well as the increasing attention on beta-scission of radical intermediates. Additionally, Lewis acid-mediated and thermally induced ring-opening of cyclobutanone derivatives have garnered renewed interest, demonstrating the unique synthetic potentials of structurally strained four-membered ring compounds for constructing organic skeletons.
Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Yujia Gao, Juan Zhang, Wenyu Shan, Weihong Fei, Jinzhong Yao, Weijun Yao
Summary: In this study, a trimerization reaction of gamma-aryl-3-butynoates was achieved through catalysis, leading to the formation of exocyclopentene derivatives with an allcarbon quaternary stereocenter. The reaction exhibited high stereoselectivity and enantioselectivity, delivering optically pure products with high enantiomeric excess values.
Article
Chemistry, Organic
Sayaji Arjun More, Rahul Dadabhau Kardile, Tung-Chun Kuo, Mu-Jeng Cheng, Rai-Shung Liu
Summary: Gold-catalyzed reactions of cycloheptatrienes with nitrosoarenes efficiently yield nitrone derivatives, and the development of aerobic oxidations and annulations using CuCl and nitrosoarenes as co-catalysts have been achieved. The study also demonstrates a novel nitroso-activated rearrangement and the successful synthesis of 5-alkoxyisoxazolidines in [2 + 2 + 1]-annulations utilizing 1,4-cyclohexadienes as hydrogen donors.
Article
Chemistry, Multidisciplinary
Vineet K. Jakhar, Alec M. Esper, Ion Ghiviriga, Khalil A. Abboud, Christian Ehm, Adam S. Veige
Summary: The reactivity of phosphaalkynes with metal alkylidyne complexes is investigated, leading to the formation of phosphametallacyclobutadiene complexes. The reversible formation/cleavage of C-C bonds can be controlled by the addition or removal of THF, enabling the transformation between tetraanionic and trianionic pincers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Rayhane Hammami, Pascale Maldivi, Christian Philouze, Sebastien Carret, Benjamin Darses, Soufiane Touil, Jean-Francois Poisson
Summary: A variety of 4-phosphinylpyrrolidin-3-ones were synthesized via a [3+2] cycloaddition reaction between aryl aldonitrones and phosphinylallenes. The products were obtained as unique 4,5-trans diastereomers in yields ranging from 47% to 80% for 23 examples. Chiral racemic allenes exhibited a moderate 2:1 to 4:1 2,5-diastereoselectivity. Under the reaction conditions, the cycloadducts undergo a rearrangement to selectively afford the corresponding pyrrolidin-3-ones. DFT calculations provided insights into the mechanism involving the homolytic cleavage of the N-O bond of the cycloadduct.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Biao Guo, Jiaying Lv, Le Lu, Ruimao Hua
Summary: A novel method for constructing the cyclopenta[c]quinoline ring has been developed, which involves the cyclization of 3-bromoindoles with internal alkynes in the presence of palladium. The mechanism of the formation of the cyclopenta[c]quinoline ring is proposed to proceed via a double [1,5] carbonsigmatropic rearrangement of the spirocyclic cyclopentadiene intermediate, generated from the cyclization of 3-bromoindoles with internal alkynes. This study also presents a new ring-expansion reaction of the pyrrole ring to pyridine via one carbon insertion into the C2-C3 bond of indoles, providing a simple and distinct route for constructing tricyclic fused-quinoline derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Wei-Jung Chiu, Ting-Yen Chu, Indrajeet J. J. Barve, Chung-Ming Sun
Summary: A Pd(II)-catalyzed [5 + 2] annulation reaction between N-triflyl aryl indoles and α,γ-substituted allenoates for the synthesis of indole-fused benzodiazepines is described. The use of N-acetylated valine amino acid as a ligand and DMSO as a cosolvent enhances the efficiency of this protocol. The reaction mechanism involves C-H activation, cyclopalladation, coordination, migratory insertion, reductive elimination, and [1,3]-H shift.
Article
Chemistry, Multidisciplinary
Biao Wang, Han Zhong, Xu Tian
Summary: An efficient cascade reaction of cyclobutanones with chalcones has been developed, using inexpensive potassium tert-butoxide as a promoter. It enables the synthesis of densely substituted cyclohex-3-ene-carboxylic acids in high yields and with high diastereoselectivities, which are difficult to prepare using conventional methods. The method offers the advantages of transition-metal-free conditions, readily available starting materials, wide scope, and high atom economy.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Tingting Yan, Kaki Raveendra Babu, Yong Wu, Yang Li, Yuhai Tang, Silong Xu
Summary: A phosphine-catalyzed olefinic cross-coupling reaction between benzyl halides and fumarates has been described, providing trisubstituted alkenes with good yields and excellent E-selectivity under metal-free conditions. Mechanistic studies suggest a catalytic cycle involving phosphorus ylide formation, Michael addition, water-assisted hydrogen transfer, and phosphine elimination.
Article
Chemistry, Physical
Changhui Lu, Yueping Lin, Minyan Wang, Jiaming Zhou, Shuo Wang, Huanfeng Jiang, Kai Kang, Liangbin Huang
Summary: In this study, a nickel-catalyzed ring-opening transformation of benzofuran with silanes was reported, selectively giving ortho-alkene-, branched/linear alkyl silane-, and alkenyl silane-substituted phenol derivatives. This reaction provides a highly desirable and underdeveloped method for the construction of valuable phenol derivatives.
Article
Chemistry, Multidisciplinary
Chen Chen, Haixia Zhao, Yue Pu, Lulu Tang, Jian Wang, Yongjia Shang
Summary: A palladium-catalyzed C-C bond activation of cyclobutanones has been developed for the construction of alkenyl and carbonylated indanones. The in-situ generated sigma-alkylpalladium intermediate can be trapped with N-tosylhydrazones and carbon monoxide, respectively. The reactions exhibit excellent functional group tolerance and are carried out under mild conditions.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Diego G. Matesanz, Laura Gamarra, Teresa Martinez del Campo, Pedro Almendros, Sara Cembellin
Summary: A highly selective Mn(I)-catalyzed dienylation of arenes and heteroarenes with acetylated allenes is reported. The method proceeds through a one-pot procedure and delivers linear 1,3-dienes as single products with high stereoselectivity and total regioselectivity. This strategy shows wide functional group tolerance and preparative scale utility, making it efficient for late-stage functionalization of complex valuable molecules. The synthetic importance is highlighted by different derivatizations of the final products, which can exhibit interesting fluorescence properties.
Article
Chemistry, Physical
Michael M. M. Gilbert, Michael J. J. Trenerry, Victoria R. R. Longley, Anthony J. J. Castro, John F. F. Berry, Daniel J. J. Weix
Summary: Cyclopropyl ketones can be cross-coupled with organozinc reagents and chlorotrimethylsilane to form 1,3-difunctionalized, ring-opened products. The redox-active terpyridine ligand and the nickel atom cooperate to enable the C-C bond activation step. This approach allows for quick access to difficult-to-make products.
