Organic Chemistry Portal
Organic Chemistry Highlights

Monday, May 23, 2016
Douglass F. Taber
University of Delaware

Oxidation in Organic Synthesis

Jianliang Xiao of the University of Liverpool developed (J. Am. Chem. Soc. 2015, 137, 8206. DOI: 10.1021/jacs.5b03956) a reagent combination that cleaved the alkenyl arene of 1 to give 2, leaving the very reactive cyclic alkene intact. István E. Markň of the Université Catholique de Louvain optimized (Org. Lett. 2015, 17, 4690. DOI: 10.1021/acs.orglett.5b02084) the electrochemical oxidative cleavage of the diacid 3 to the ketone 4. Jong Chan Lee of Chung-Ang University showed (Synlett 2015, 26, 2434. DOI: 10.1055/s-0035-1560467) that in the presence of catalytic BiBr3, 30% H2O2 efficiently oxidized the alcohol 5 to the aldehyde 6. Galia Maayan of Technion designed (Chem. Commun. 2015, 51, 11096. DOI: 10.1039/C5CC04266F) a elegant TEMPO and 1,10-phenanthroline containing peptoide trimer that catalyzed the oxidation of the alcohol 7 to the aldehyde 8.

Lidia De Luca of the Universitŕ degli Studi di Sassari used (Org. Lett. 2015, 17, 3666. DOI: 10.1021/acs.orglett.5b01579) TCAA to oxidize the aldehyde 8 to the corresponding acid chloride, that was coupled in situ with the alcohol 9 to give the ester 10. Jean-Michele Vatčle of the Université Lyon I showed (Synlett 2015, 26, 2280. DOI: 10.1055/s-0034-1381056) that with catalytic TEMPO, the oxidation could start with the alcohol 11, and that an amine 12 could also participate in the coupling, leading to the amide 13. Shouyun Yu of Nanjing University devised (Org. Lett. 2015, 17, 5064. DOI: 10.1021/acs.orglett.5b02547) the reagent 15, that directly converted the aldehyde 14 to the nitrile 16. Yan Xiong of Chongqing University prepared (J. Org. Chem. 2015, 80, 7212. DOI: 10.1021/acs.joc.5b01102) the keto nitrile 18 by oxidizing the silyl ether 17 in the presence of TMS-CN.

Song Song and Ning Jiao of Peking University (Org. Lett. 2015, 17, 4702. DOI: 10.1021/acs.orglett.5b02155) and Chaozhong Li of the Shanghai Institute of Organic Chemistry (J. Am. Chem. Soc. 2015, 137, 9820. DOI: 10.1021/jacs.5b06821) independently developed the radical decarboxylative conversion of an acid 19 to the azide 20. The transformation proceeded with substantial preference for the equatorial diastereomer. Sanzhong Luo of the Institute of Chemistry, Chinese Academy of Sciences used (Org. Lett. 2015, 17, 4392. DOI: 10.1021/acs.orglett.5b02322) a chiral Cu catalyst to elaborate the stereogenic center of 23. It will be interesting to see what applications this (potentially temporary) stereogenic center might have in target-directed synthesis. Eun Jin Cho, also of Chung-Ang University, oxidized (Adv. Synth. Catal. 2015, 357, 2187. DOI: 10.1002/adsc.201500257) the amine 24 to the aldehyde 8. Yongbo Zhou and Shuang-Feng Yin of Hunan University observed (Adv. Synth. Catal. 2015, 357, 2924. DOI: 10.1002/adsc.201500515) selectivity in the oxidation of the diamine 25 to the benzoxazole 27.

Ganapati Subray Shankarling of the Institute of Chemical Technology, Mumbai also observed (J. Org. Chem. 2015, 80, 7876. DOI: 10.1021/acs.joc.5b00582) selectivity in the oxidation of the diamine 28 to the nitro aromatic 30. Yujiro Hayashi of Tohoku University found (Angew. Chem. Int. Ed. 2015, 54, 12986. DOI: 10.1002/anie.201505192) that the nitro compound 31 could be oxidized in the presence of the amine 32, leading to the amide 33.

D. F. Taber, Org. Chem. Highlights 2016, May 23.