Organic Chemistry Portal
Organic Chemistry Highlights

Monday, September 23, 2019
Douglass F. Taber
University of Delaware

Reactions of Alkenes: The Trost Synthesis of Piericidin A

Kiyoshi Tanemura of Nippon Dental University developed conditions for the Markovnikov hydrohalogenation of alkenes, converting 1 to the iodide 2 (Tetrahedron Lett. 2018, 59, 4293. DOI: 10.1016/j.tetlet.2018.10.043). Jingchao Chen and Baomin Fan of Yunnan Minzu University reported related results (Org. Lett. 2018, 20, 6859. DOI: 10.1021/acs.orglett.8b02980). Forrest E. Michael of the University of Washington oxidized 3 to the enimide 4 (Org. Lett. 2019, 20, 6975. DOI: 10.1021/acs.orglett.8b03159). Keary M. Engle of Scripps-Lo Jolla converted 5 to the unsaturated nitrile 6 (J. Am. Chem. Soc. 2018, 140, 8069. DOI: 10.1021/jacs.8b03704). Ohyun Kwon of UCLA devised a strategy for the net reductive removal of the propenyl group (hydrodealkenylation) from 7, leading to 8 (ACS Catal. 2018, 8, 5188, DOI: 10.1021/acscatal.8b01081; Science 2019, 364, 681, DOI: 10.1126/science.aaw4212).

Tomoya Miura and Masahito Murakami of Kyoto University assembled 11 by adding 10 to 9 (Angew. Chem. Int. Ed. 2018, 57, 15455. DOI: 10.1002/anie.201809115). Ryan A. Shenvi, also of Scripps-La Jolla, prepared 14 by adding the alkene 12 to benzaldehyde (J. Am. Chem. Soc. 2018, 140, 16976. DOI: 10.1021/jacs.8b11699). Weibing Liu of the Guangdong University of Petrochemical Technology added chloroform to 15 under free radical conditions to give 16 (Org. Chem. Front. 2018, 5, 3143. DOI: 10.1039/C8QO00868J). Xi-Sheng Wang of the University of Science and Technology of China described related results (Org. Lett. 2018, 20, 7283. DOI: 10.1021/acs.orglett.8b03208). Lei Liu of Shandong University devised a branching strategy for the preparation of 18 by the addition of 17 to 15 (Org. Lett. 2018, 20, 6836. DOI: 10.1021/acs.orglett.8b02954).

Francesco Fini of the University of Modena and Reggio Emilia and Carla Carfanga of the University of Bologna showed that the bis-alkoxycarbonylation of 19 led to 20 with high diastereocontrol (Adv. Synth. Catal. 2018, 360, 3507. DOI: 10.1002/adsc.201701597). Yannick Landais of the University of Bordeaux found that di-t-butyl hyponitrite effectively promoted the addition of 21 to 15, leading, after trapping with Ts-CN, to the nitrile 22 (Eur. J. Org. Chem. 2018, 4058. DOI: 10.1002/ejoc.201800444). Pinhong Chen and Guosheng Liu of the Shanghai Institute of Organic Chemistry observed that the larger aryl group selectively transferred from the diaryliodinium salt, converting 23 to 24 (Angew. Chem. Int. Ed. 2018, 57, 15871. DOI: 10.1002/anie.201810405). Ramesh Giri of the University of New Mexico synthesized 28 by adding 26 and then 27 sequentially to 25 (J. Am. Chem. Soc. 2018, 140, 15586. DOI: 10.1021/jacs.8b09401).

Piericidin A (33), isolated from Streptomyces mobaraensis, is a potent inhibitor of mitochondrial respiration. Barry M. Trost of Stanford University devised a concise preparation of 33, based on the stepwise addition of alkyne 29 and alkyne 31 to the linchpin propene 30, to give 32 (J. Am. Chem. Soc. 2018, 140, 11623. DOI: 10.1021/jacs.8b08974).

D. F. Taber, Org. Chem. Highlights 2019, September 23.