C-H Functionalization: The Yang Synthesis of Fennebricin A
Shelley D. Minteer of the University of Utah used a biofuel cell to oxidize 1 to the alcohol 2 (Angew. Chem. Int. Ed. 2020, 59, 8969. DOI: 10.1002/anie.202003032). Converting 3 to 4, Yoshihiro Ueda of Kyoto University demonstrated the long-anticpated activation of C-H bonds β to silicon for nitrene insertion (Chem. Commun. 2020, 56, 5759. DOI: 10.1039/D0CC00959H). David A. Nicewicz of the University of North Carolina achieved remarkable regioselectivity in the oxidation of 5 to the ketone 6 (J. Am. Chem. Soc. 2020, 142, 10325. DOI: 10.1021/jacs.0c04422). David A. Nagib of Ohio State University cyclized 7 to the 2-oxazoline 8 (J. Am. Chem. Soc. 2020, 142, 5429. DOI: 10.1021/jacs.0c01318).
Nathan D. Schley of Vanderbilt University borylated 9 selectively to 10 (J. Am. Chem. Soc. 2020, 142, 6488. DOI: 10.1021/jacs.0c00524). John Hartwig of the University of California, Berkeley reported a parallel investigation (Science 2020, 368, 736. DOI: 10.1126/science.aba6146). Bruno Melillo and Jin-Quan Yu of Scripps/La Jolla achieved remarkable regioselectivity in the coupling of 11 with 12 to give 13 (Angew. Chem. Int. Ed. 2020, 59, 7783. DOI: 10.1002/anie.202000632). Jie Wu of the National University of Singapore observed that the alkenylation of the cyclopentanol 14 with 15 proceeded distal to the electron-withdrawing alcohol, leading to 16 (Nature Commun. 2020, 11, 1956. DOI: 10.1038/s41467-020-15878-6). Daniel Seidel of the University of Florida effected oxidation of the piperidine 17 and alkylation of that product with benzyl bromide, leading after reduction to 18 (Nature Chem. 2020, 12, 545. DOI: 10.1038/s41557-020-0438-z).
Massimo Bietti of the UniversitÓ "Tor Vergata" and Miquel Costas of the Universitat de Girona achieved high regioselectivity and enantioselectivity in the conversion of 19 to 20 (J. Am. Chem. Soc. 2020, 142, 1584. DOI: 10.1021/jacs.9b12239). Professor Yu described a related oxidative lactonization (J. Am. Chem. Soc. 2020, 142, 6769. DOI: 10.1021/jacs.0c01214). Cong Lin and Liang Shen of the Jiangxi Science & Technology Normal University assembled the lactam 23 by coupling 21 with 22 (Synlett 2020, 31, 889. DOI: 10.1055/s-0037-1610756).
Francesco Secci of the UniversitÓ degli Studi di Cagliari observed remarkable regioselectivity in the cyclization of 24 to the cyclopentanone 25 (Org. Biomol. Chem. 2020, 18, 3684. DOI: 10.1039/D0OB00532K). Jeremy A. May of the University of Houston used a Rh catalyst to cyclize 26 to 27 (Org. Lett. 2020, 22, 3039. DOI: 10.1021/acs.orglett.0c00798).
Fennebricin A (31), isolated from the skin of the South China Sea nudibranch Jurunna funebris, shows interesting cytotoxicity. Yu-Rong Yang of the Kunming Institute of Botany prepared the starting material 30 for the synthesis of 31 by coupling 28 with 29 (Org. Lett. 2020, 22, 4489. DOI: 10.1021/acs.orglett.0c01493).