Organic Chemistry Portal
Organic Chemistry Highlights

Monday, July 10, 2017
Douglass F. Taber
University of Delaware

Enantioselective Preparation of Alcohols and Amines: The Kalesse Synthesis of Aetheramide A

Matthew S. Sigman of the University of Utah assembled (J. Am. Chem. Soc. 2016, 138, 15881. DOI: 10.1021/jacs.6b11486) the ether 2 by adding a phenol to the allylic alcohol 1. Lukasz Albrecht of the Lodz University of Technology converted (Eur. J. Org. Chem. 2016, 4302. DOI: 10.1002/ejoc.201600872) the unsaturated aldehyde 3 to the alcohol 4 by way of the intermediate aziridine. Géraldine Masson of the Institut de Chimie des Substances Naturelles prepared (J. Am. Chem. Soc. 2015, 137, 11950, DOI: 10.1021/jacs.5b08515; J. Org. Chem. 2016, 81, 10154, DOI: 10.1021/acs.joc.6b01256) the aminal 6 by adding nitrosobenzene to the diene 5. Peng-Fei Xu of Lanzhou University established (Org. Chem. Front. 2016, 3, 598. DOI: 10.1039/C6QO00018E) oxygenated quaternary centers using this approach (not illustrated). Taichiro Touge of Takasago International Corporation and Yoshihito Kayaki of the Tokyo Institute of Technology effected (J. Am. Chem. Soc. 2016, 138, 10084. DOI: 10.1021/jacs.6b05738) enantioselective reduction of the benzophenone 7 to give 8.

The crossed benzoin condensation of benzaldehyde 9 with acetaldehyde could give either 10 or the regioisomeric product. Michael Müller of Albert-Ludwigs-Universität Freiburg developed (Chem. Eur. J. 2016, 22, 13999. DOI: 10.1002/chem.201602084) enzyme systems that delivered either regioisomer selectively and in high ee. Many methods have been put forward for the enantioselective allylation of an aldehyde. Benjamin List of the Max-Planck-Institut für Kohlenforschung established (Angew. Chem. Int. Ed. 2016, 55, 13200. DOI: 10.1002/anie.201607828) a practical alternative, the organocatalyzed addition of commercial 12 to 11 to give the homoallylic alcohol 13.

Hui Lv and Xumu Zhang of Wuhan University hydrogenated (Chem. Commun. 2016, 52, 11850. DOI: 10.1039/C6CC06047A) the diene 14 to 15 in high ee. Baoguo Zhao of Shanghai Normal University designed (J. Am. Chem. Soc. 2016, 138, 10730. DOI: 10.1021/jacs.6b03930) effective organocatalysts for the enantioselective transamination of 16 with 17 to give 18. Song Yang of Guizhou University and Yonggui Robin Chi of Nanyang Technological University added (Angew. Chem. Int. Ed. 2016, 55, 12280. DOI: 10.1002/anie.201606571) the unsaturated aldehyde 19 to 20 under oxidative conditions to give 21. Shunsuke Kotani of Kumamoto University constructed (Tetrahedron Lett. 2016, 57, 4217. DOI: 10.1016/j.tetlet.2016.08.013) the α-quaternary α-amino ester 24 by adding 22 to 23.

Bin Xu of Shanghai University and Ming-Hua Xu of the Shanghai Institute of Materia Medica devised (Org. Chem. Front. 2016, 3, 944. DOI: 10.1039/C6QO00191B) a general route to aryl glycine derivatives such as 26, based on the addition of an areneboronic acid to an imine 25. Choong Eui Song of Sungkyunkwan University took advantage (Angew. Chem. Int. Ed. 2016, 55, 10825. DOI: 10.1002/anie.201605167) of the enhanced acidity of thioesters, adding 28 to 27 to give 29.

Aetheramide A (33), isolated from the myxobacteria genus Aetherobacter, showed low nanomolar inhibition of HIV-1 infection. Markus Kalesse of Leibniz Universität Hannover established (Chem. Eur. J. 2016, 22, 11210. DOI: 10.1002/chem.201602682) the isolated secondary allylic center of 33 by adding 31 to 30 to give 32.

D. F. Taber, Org. Chem. Highlights 2017, July 10.