Enantioselective Synthesis of Alcohols and Amines: The You Synthesis of Chelonin A
Bernhard Hauer of the University of Stuttgart optimized the enzymatic hydration of 1 to 2 (Angew. Chem. Int. Ed. 2019, 58, 173. ). James P. Morken of Boston College uncovered the selective oxidation of the bis-boronate derived from 3, leading to 4 (Org. Lett. 2019, 21, 3760. ). Satoshi Maeda and Masaya Sawamura of Hokkaido University effected the enantioselective hydroxylation of 5 to 6 (J. Am. Chem. Soc. 2019, 141, 6817. ). Sabine L. Flitsch of the University of Manchester used a wild-type cytochrome P450 monooxygenase to convert 7 to 8 (Angew. Chem. Int. Ed. 2019, 58, 5668. ).
Gregory C. Fu of Caltech (Angew. Chem. Int. Ed. 2019, 58, 3571. ) and Martin Oestreich of the Technische Universitšt Berlin (Angew. Chem. Int. Ed. 2019, 58, 3575. ) simultaneously described the enantioselective coupling of 10 with racemic 9, leading to 11. Michael J. Krische of the University of Texas assembled 14 by coupling 12 with 13 (Chem. Commun. 2019, 55, 981. ).
Wing-Yiu Yu of the Hong Kong Polytechnic University cyclized 15 to the lactam 16 (J. Am. Chem. Soc. 2019, 141, 3849. ). Sukbok Chang of KAIST and Gang He and Gong Chen of Nankai University used an iridium catalyst to effect related transformations (Nature Catal. 2019, 2, 219, ; (J. Am. Chem. Soc. 2019, 141, 7194, ). Richmond Lee of the Singapore University of Technology and Design and Choon-Hong Tan of Nanyang Technological University converted the racemic bromide 17 to the azide 18 in high ee (Science 2019, 363, 400. ).
Kendall N. Houk of UCLA and Bin Tan of the Southern University of Science and Technology reported the Ugi combination of 19, 20, 21 and 22, leading to 23 in high ee (Science 2018, 361, eaas8707. ). Michael P. Doyle of the University of Texas at San Antonio assembled 26 by cyclizing 25 with 24 (Org. Lett. 2019, 21, 40. ). Robert S. Paton of Colorado State University and and Darren J. Dixon of the University of Oxford added TosMIC (28) to 27 to give the 2-imidazoline 29 (Chem. Eur. J. 2019, 24, 17660. ). Qi-Xiang Guo of Southwest University showed that the free amine 30 could be combined with a catalytic chiral aldehyde, then alkylated with 31, leading to 32 (J. Am. Chem. Soc. 2019, 141, 5159. ).
Chelonin A 35, isolated from the marine sponge Chelonaplysilla sp., shows antibiotic and anti-inflammatory activity. Shu-Li You of the Shanghai Institute of Organic Chemistry set the absolute configuration of 35 by cyclizing 33 to 34 (J. Am. Chem. Soc. 2019, 141, 2228. ).