Heteroaromatics: The Kwon Synthesis of Plakorsin D
Yewen Fang of the Ningbo University of Technology, Xiaoping Jin of Zhejiang Pharmaceutical College, and Yan Li of Hubei University assembled the furan 3 by the conjugate addition of 2 to the enone 1 (Org. Chem. Front. 2021, 8, 1732. ). Yumei Xiao and Hongchao Guo of China Agricultural University prepared the furan 6 by the combination of the alkyne 4 with the keto nitrile 5 (Adv. Synth. Catal. 2020, 362, 5026. ). Maren Podewitz and Thomas Magauer of the Leopold-Franzens-University Innsbruck oxidized the alkenyl sulfide 7 with chloramine-T, leading to the pyrrole 8 (J. Am. Chem. Soc. 2021, 143, 9002. ). Renata Marcia de Figueiredo and Jean-Marc Campagne of the University of Montpellier effected the oxidative rearrangement of the alkenyl aziridine 9 to the pyrrole 10 (Synlett 2021, 32, 517. ).
Alexander F. Khlebnikov of St. Petersburg State University combined the enamine 12 with the isoxazol-5-one 11 to give the pyridine 13 (J. Org. Chem. 2021, 86, 6888. ). Jonathan R. Scheerer of the College of William & Mary reduced the azido ester 14, then added the propargyl alcohol 15, leading to the pyridine 16 (J. Org. Chem. 2021, 86, 5863. ). The preparation of the pyridine 19 from 17 developed by Osamu Tamura of Showa Pharmaceutical University proceeded by initial C-H alkenylation with 18, followed by electrocyclization (Org. Lett. 2021, 23, 1659. ). Xue-Qiang Chu of Nanjing Tech University showed that the preparation of the pyridine 21 by the combination of the tertiary allylic alcohol 20 with acetone proceeded with high regioselectivity (Org. Biomol. Chem. 2021, 19, 2277. ).
Masahiko Hayashi of Kobe University showed that ethylene 23 served as an effective hydrogen acceptor in the oxidative cyclization of the diketone 22 to the indole 24 (Org. Lett. 2021, 23, 1530. ). Modhu Sudan Maji of the Indian Institute of Technology Kharagpur prepared the indole 27 by coupling pyrrole aldehyde 25 with the allylboronic acid 26 (Chem. Commun. 2021, 57, 5274. ). Qiuqin He and Renhua Fan of Fudan University effected the oxidative cyclization of the aryl alkyne 28 to the indole 29 (Org. Chem. Front. 2021, 8, 3004. ). The same authors also described the complementary oxidation of 28 to the indole 30 (Org. Lett. 2021, 23, 2130. ).
The furan fatty acid plakorsin D (34) was isolated from the South China sea sponge Plakortis simplex. Ohyun Kwon of UCLA devised a simple route to 34, based on the assembly of 33 by the combination of 31 with 32 (Angew. Chem. Int. Ed. 2021, 60, 8874. ).
Congratulations to Benjamin List and David W. C. MacMillan, 2021 Nobel Prize in Chemistry for their contributions to the development of enantioselective organocatalysis!