Monday, April 22, 2019
Douglass F. Taber
University of Delaware
C-N Ring Construction: The Mori Synthesis of Lycopodine
Bhoopendra Tiwari of the Centre of Biomedical Research, Lucknow, and Jawahar L. Jat of the Baba Saheb Bhim Rao Ambedkar University showed that using the reagent 2, 1 could be selectively converted to the aziridine 3 (J. Org. Chem. 2018, 83, 12255. ). Eiji Tayama of Niigata University achieved high diastereoselectivity in the alkylation of the azetidine 4 to 5 (Org. Biomol. Chem. 2018, 16, 5833. ).
Fang Xie and Wanbin Zhang of Shanghai Jiao Tong University (Org. Lett. 2018, 20, 6564. ) and Chun-Jiang Wang of Wuhan University (Adv. Synth. Catal. 2018, 360, 4715. ) independently observed that the pyrroline 6 could be alkylated with 7 with high linear selectivity, leading to 8. Xiaoming Feng of Sichuan University constructed 11 by combining 9 with 10 (Adv. Synth. Catal. 2018, 360, 2831. ). Kazunori Takahashi of Hoshi University effected the reductive cyclization of 12 to 13 (J. Org. Chem. 2018, 83, 10636. ). Zhichao Jin of Guizhou University and Yonggui Robin Chi of Nanyang Technological University used a carbene catalyst to mediate the assembly of 16 by the addition of 15 to 14 (ACS Catal. 2018, 8, 9859. ).
Ohyun Kwon of UCLA developed a phosphine catalyst that mediated the enantioselective addition of 18 to 17, leading to 19 (Org. Lett. 2018, 20, 6089. ). Ganesh Pandey, also of the Centre of Biomedical Research, observed high diastereoselectivity in the reductive allylation of 20 to 21 (Tetrahedron 2018, 74, 6317. ). Takuya Okada and Naoki Toyooka of the University of Toyama used baker's yeast without added sugar to reduce the β-keto ester 22 to the alcohol 23 (Tetrahedron Lett. 2018, 59, 3797. ). Michael A. Kerr of the University of Western Ontario observed that the nitrone prepared by the combination of 24 with 25 cyclized to 26 with high diastereoselectivity (J. Am. Chem. Soc. 2018, 140, 8415. ).
Frank Glorius of the Westfälische Wilhelms-Universität Münster arylated 27 to give 28 in high ee (Angew. Chem. Int. Ed. 2018, 57, 9950. ). Markus R. Heinrich of the Friedrich-Alexander-Universität Erlangen-Nürnberg designed the amide 29 that cyclized to the medium-ring lactam 30 (Org. Lett. 2018, 20, 7825. ).
Given the energy intensity of the Haber-Bosch process, inorganic chemists have worked for years to achieve the reduction of atmospheric nitrogen to ammonia at ambient pressure and temperature. Twenty years ago, Miwako Mori of Hokkaido University, en route to lycopodine 33, showed that 31 could be cyclized to 32 by reducing dry air (Angew. Chem. Int. Ed. 1998, 37, 636. ).
D. F. Taber, Org. Chem. Highlights 2019, April 22.