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Kshirsagar AS, More SA, Liu RS. Stereo- and regiocontrol in intermolecular [2+2] cycloadditions between diarylketenes and allenamides to access substituted α-methylenecyclobutanones. Chem Commun (Camb) 2023; 59:11967-11970. [PMID: 37724358 DOI: 10.1039/d3cc03979j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
The development of intermolecular [2+2] cycloadditions between allenamides and diarylketenes is described. α-Aryldiazo arylketones are employed as ketene precursors that react smoothly with allenamides in the presence of a P(C6F5)3 promoter. High diastereoselectivity (dr > 20 : 1) with endo-regioselectivity can be achieved when two aryl groups of ketenes have opposite electronic properties. The role of P(C6F5)3 is to increase the reaction yields, but also enhancing stereoselectivity.
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Affiliation(s)
- Akshay Suresh Kshirsagar
- A Frontier Research Center of Matter Science and Technology, Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, ROC.
| | - Sayaji Arjun More
- A Frontier Research Center of Matter Science and Technology, Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, ROC.
| | - Rai-Shung Liu
- A Frontier Research Center of Matter Science and Technology, Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, ROC.
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Arai S, Inagaki S, Nakajima M, Nishida A. Regio-divergent nickel catalysis: intramolecular [4+2] and [2+2] cycloaddition reactions between vinylallenes and alkynes. Chem Commun (Camb) 2021; 57:11268-11271. [PMID: 34635883 DOI: 10.1039/d1cc03942c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vinylallenes have been recognized as versatile C2 and C4 components for nickel-catalyzed intramolecular [4+2] and [2+2] cycloadditions. The former reaction was promoted by a Ni(0) complex (up to quantitative yield), and a Ni(II) salt was a key species for the latter reaction to give the corresponding regio- and stereocontrolled cycloadducts (up to 88% yield). DFT studies revealed that both reaction pathways involve a concerted mechanism through the activation of different C-C multiple bonds in the substrates.
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Affiliation(s)
- Shigeru Arai
- Graduate School of Pharmaceutical Sciences, Chiba University 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan. .,Molecular Chirality Research Center, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Saki Inagaki
- Graduate School of Pharmaceutical Sciences, Chiba University 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan.
| | - Masaya Nakajima
- Graduate School of Pharmaceutical Sciences, Chiba University 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan. .,Molecular Chirality Research Center, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Atsushi Nishida
- Graduate School of Pharmaceutical Sciences, Chiba University 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan. .,Molecular Chirality Research Center, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
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