Organic Chemistry Portal
Organic Chemistry Highlights

Monday, February 11, 2019
Douglass F. Taber
University of Delaware

Enantioselective Synthesis of Alcohols and Amines: The Odagi/Nagasawa Synthesis of Gracilamine

The computational approach to ligand design developed by Hajime Ito of Hokkaido University enabled the enantioselective hydroboration of 1 to 2 (Nature Commun. 2018, 9, 2290. DOI: 10.1038/s41467-018-04693-9). Hassan Hosseini-Monfared of the University of Zanjan devised a graphene-based Mn catalyst that directed the enantioselective epoxidation of 3 to 4 (Tetrahedron 2018, 74, 2202. DOI: 10.1016/j.tet.2018.03.027). Santanu Mukherjee of the Indian Institute of Science, Bangalore effected the enantioselective cyclization of 5 to 6 (Org. Lett. 2018, 20, 1300. DOI: 10.1021/acs.orglett.8b00002). Chang-Woo Cho of Kyungpook National University added hydroxylamine to 7 to give the 2-oxazoline 8 in high ee (Org. Biomol. Chem. 2018, 16, 657. DOI: 10.1039/C7OB02722B).

Erika Nakashima and Hisashi Yamamoto of Chubu University immobilized an organocatalyst to mediate the flow aldol addition of acetone to 9, leading to 10 (Chem. Eur. J. 2018, 24, 1076. DOI: 10.1002/chem.201705982). Hyunsoo Han of the University of Texas at San Antonio assembled the lactone 13 by adding 12 to 11 (Org. Lett. 2018, 20, 1448. DOI: 10.1021/acs.orglett.8b00230). Liu-Zhong Gong of the University of Science and Techology of China coupled 15 with 14 to give 16 (J. Am. Chem. Soc. 2018, 140, 3177. DOI: 10.1021/jacs.7b12628). Wen-Hua Zheng of Nanjing University achieved high selectivity in the oxidation of 17 to 18 (Org. Lett. 2018, 20, 518. DOI: 10.1021/acs.orglett.7b03581).

David Monge, Rosario Fernádez and José M. Lassaletta of the Universidad de Sevilla prepared 21 by adding 20 to 19, followed by oxidation (Chem. Eur. J. 2018, 24, 6854. DOI: 10.1002/chem.201801052). Bi-Jie Li of Tsinghua University developed a Rh catalyst for the assembly of 24 by the addition of 23 to 22 (J. Am. Chem. Soc. 2018, 140, 506. DOI: 10.1021/jacs.7b12054). Jian Wang, also of Tsinghua University, added the azirine 26 to the aldehyde 25, leading to 27 (Angew. Chem. Int. Ed. 2018, 57, 3767. DOI: 10.1002/anie.201712785). Jin-Quan Yu of Scripps/La Jolla effected the enantioselective coupling of 28 with 29 to give 30 (J. Am. Chem. Soc. 2018, 140, 6545, DOI: 10.1021/jacs.8b03509; 5322, DOI: 10.1021/jacs.8b01094).

Minami Odagi and Kazuo Nagasawa of the Tokyo University of Agriculture and Technology set the absolute configuration of gracilamine 34 by the enantioselective Mannich coupling of 31 with sesamol (32) to give 33 (Angew. Chem. Int. Ed. 2018, 57, 2229. DOI: 10.1002/anie.201708575). It is instructive to compare this approach to that reported by Ma (The Ma Synthesis of Gracilamine 2013, August 5).

D. F. Taber, Org. Chem. Highlights 2019, February 11.