Enantioselective Synthesis of Alcohols and Amines: The Zhang/Tu Synthesis of Eupomatilone-6

Vicente Gotor-Fernández and Iván Lavandera of the Universidad de Oviedo optimized the enzymatic reduction of the chloroketone 1 to the chlorohydrin 2, then telescoped that to begin with the 1-chloroalkyne (not illustrated) (Org. Biomol. Chem. 2022, 20, 9650. DOI: 10.1039/D2OB01953A). Jerome Waser of the Ecole Polytechnique Fédérale de Lausanne used a Pd catalyst to combine the propargyl amine 3 with the hemiacetal 4, then hydrogenated the product, leading to the protected 1,2-aminoalcohol 5 (ACS Catal. 2022, 12, 7565. DOI: 10.1021/acscatal.2c01809).

Robert Vianello and Maja Majerić Elenkov of the Ruder Bošković Institute combined sodium cyanide with an enzyme to convert racemic epichlorohydrin 6 to the β-hydroxy nitrile 7 (Adv. Synth. Catal. 2022, 364, 2576. DOI: 10.1002/adsc.202200342). Qiaorong Han and Liang-An Chen of Nanjing Normal University assembled the keto benzoate 10 by coupling the aldehyde 9 with the acid chloride 8 (J. Am. Chem. Soc. 2022, 144, 23019. DOI: 10.1021/jacs.2c10072). Frank Glorius of the Westfälische Wilhelms-Universität Münster used a chromium catalyst and light to mediate the preparation of the alcohol 12 by the addition of the allyl silane 11 to the aldehyde 9 (ACS Catal. 2022, 12, 12281. DOI: 10.1021/acscatal.2c03960). Hiroyuki Suga of Shinshu University constructed the protected diol 15 by adding the epoxide 14 to the aldehyde 13 (Org. Lett. 2022, 24, 4739. DOI: 10.1021/acs.orglett.2c01682).

Johannes M. Wahl of Johannes Gutenberg-Universität Mainz used the reagent 17 to convert the cyclobutanone 16 to the lactam 18 (Org. Lett. 2022, 24, 6171. DOI: 10.1021/acs.orglett.2c02361). Enrique Gómez-Bengoa of the University of the Basque Country UPV/EHU and Rafael Chinchilla of the University of Alicante used a diamine-derived organocatalyst to mediate the addition of the aldehyde 19 to the azodicarboxylate 20, leading to the α-quaternary amine 21 (J. Org. Chem. 2022, 87, 14507. DOI: 10.1021/acs.joc.2c01919).

Yongsheng Yang of Wuhan Textile University achieved high diastereoselectivity in the reductive addition of the iodide 23 to the valine derivative 22, leading to 24 (Tetrahedron 2022, 123, 132965. DOI: 10.1016/j.tet.2022.132965). René Peters of the Universität Stuttgart used a Pd catalyst to mediate the addition of the alkyne 26 to the imine 25 to give the propargyl amine 27 (Angew. Chem. Int. Ed. 2022, 61, e202206835. DOI: 10.1002/anie.202206835). Yu-Feng Zhang, Zhong-Liang Li and Xin-Yuan Liu of the Southern University of Science and Technology assembled the amine 30 by adding the α-bromoester 29 to the enone 28 (J. Am. Chem. Soc. 2022, 144, 18081. DOI: 10.1021/jacs.2c08035). Yan-Hong He and Zhi Guan of Southwest University and Chu-Sheng Huang of Nanning Normal University used electrolysis to prepare the diketone 33 by the oxidization of the indole 31 in the presence of acetone 32 (Angew. Chem. Int. Ed. 2022, 61, e202203666. DOI: 10.1002/anie.202203666).

Eupomatilone-6 (36) was isolated from the Australian shrub Eupomatia bennettii. En route to 36, Fu-Min Zhang of Wuyi University and Yong-Qiang Tu of Lanzhou University prepared the lactone 35 by the enantioselective Baeyer-Villiger oxidation of the racemic cyclobutanone 34 (Chem. Sci. 2022, 13, 8429. DOI: 10.1039/D2SC02079C).