Monday, January 18, 2016
Douglass F. Taber
University of Delaware
C-H Functionalization: The Baudoin synthesis of Aeruginosin 298A
Ronny Neumann described (J. Am. Chem. Soc. 2015, 137, 5916. ) a procedure for the oxidation of a methyl arene 1 selectively to the aldehyde 2. This could be made electrocatalytic. Jin-Quan Yu of Scripps/La Jolla found (Angew. Chem. Int. Ed. 2015, 54, 6545. ) conditions for the selective amination of the proximal methyl group of 3 with 4 to the amine 5. John T. Groves of Princeton University showed (J. Am. Chem. Soc. 2015, 137, 5300. ) that Mn-catalyzed azidation of sclareolide 6 proceeded selectively to give 7. Essentially simultaneously, three research groups, Yuhong Zhang of Zhejiang University (Org. Lett. 2015, 17, 1340. ), Bing-Feng Shi, also of Zhejiang University (Chem. Commun. 2015, 51, 7341. ) and Xinhua Xu and Shuang-Feng Yin of Hunan University (Org. Lett. 2015, 17, 1970. ) described conditions for the selective sulfenylation of 8 to 9.
Maurizio Fagnoni of the University of Pavia and Ilhyong Ryu of Osaka Prefecture University developed (Org. Lett. 2015, 17, 1292. ) a protocol for the preparation of 12 by the selective alkylation of 10 with 11. Peipei Sun of Nanjing Normal University used (Chem. Commun. 2015, 51, 7546. ) the cinnamic acid 14 to prepare 15 by the alkenylation of 13. Professor Shi showed (Chem. Commun. 2015, 51, 7899. ) that the methyl group of 16 could be alkenylated with the iodide 17 to give 18. Jingsong You of Sichuan University prepared (Org. Lett. 2015, 17, 1292. ) the alkene 21 by combining 19 with the alkyne 20.
Nuno Maulide of the University of Vienna and Carlos A. M. Afonso of the University of Lisbon cyclized (Chem. Eur. J. 2015, 21, 1449. ) the amide 22 to the β-lactam 23 without transition metal catalysis. Tsutomu Kimura and Tsuyoshi Satoh of the Science University of Tokyo observed (Tetrahedron 2015, 71, 5952. ) that the carbene generated from 24 by exposure to 25 cyclized selectively to pyrrolidine 26. Alexei V. Novikov of the University of North Dakota established (Tetrahedron Lett.2015, 56, 2269. ) a two-step procedure for cyclizing 27 to the γ-lactone 28. Liming Zhang of the University of California, Santa Barbara used (J. Am. Chem. Soc. 2015, 137, 5316. ) a gold catalyst, with oxidation by 30, to cyclize 29 to 31.
En route to Aeruginosin 298A, Olivier Baudoin of the Université Claude Bernard Lyon 1 prepared (Angew. Chem. Int. Ed. 2015, 54, 4919, ; Chem. Eur. J. 2015, 21, 9370, ) 34 by the direct arylation of 32 with 33. Completion of the synthesis included coupling with 35, previously prepared ( 2013, September 16) by Professor Baudoin using intramolecular C-H insertion.
D. F. Taber, Org. Chem. Highlights 2016, January 18.