Functional Group Interconversion: The Kobayashi Synthesis of Resolvin D4
Junfeng Zhao of Jiangxi Normal University converted the oxazolidinone 1 to the ynamide 3 by reaction with 2 (Org. Lett. 2018, 20, 280. ). Gerald B. Hammond of the University of Louisville and Bo Xu of Donghua University added HCl to the bromoalkyne 4, leading to 5 (ACS Catal. 2018, 8, 904. ). Congyang Wang of the Institute of Chemistry of the Chinese Academy of Sciences devised a Mn-catalyzed procedure for converting the alkyne 6 to the silyl alkene 7 (Angew. Chem. Int. Ed. 2018, 57, 923. ). Zhaofu Shang and Buxing Han of the same Institute used calcium carbide as a water trap to drive the addition of methanol 8 to CO2 to give dimethyl carbonate 9 (Chem. Commun. 2018, 54, 4410. ). The inexpensive calcium carbide may be of general utility as a water trap for organic reactions.
Chengfeng Xia of Yunnan University alkylated 10 with TMS-CN under oxidative conditions, leading to 11 (Chem. Commun. 2018, 54, 2854. ). Ningbo Li and Wenjie Zhao of Shanxi Medical University and Xinhua Xu of Hunan University developed a Zr catalyst for the preparation of the amino alcohol 14 by the opening of the epoxide 12 with the amine 13 (Tetrahedron 2018, 74, 1033. ). Jonas C. Peters and Greg C. Fu of Caltech observed high diastereoselectivity in the coupling of 15 with 16 to give 17 (J. Am. Chem. Soc. 2017, 139, 17707. ). Ji-Chang Xiao of the Shanghai Institute of Organic Chemistry devised conditions for the assembly of the ether 20 by activation of the alcohol 18 for coupling with 19 (Chem. Commun. 2018, 54, 7034. ). Alternative improvements for such couplings were described by Munetaka Kunishima of Kanazawa University (J. Org. Chem. 2018, 83, 4568. ), Janez Košmrlj of the University of Ljubljana and Tsuyoshi Taniguchi of Kanazawa University (J. Org. Chem. 2018, 83, 4712. ) and Tibor Soós of the Hungarian Academy of Sciences (J. Org. Chem. 2018, 83, 2869. ).
Jun-ichi Yoshida of Kyoto University devised flow conditions for the reductive coupling of 21 with 22 to give the amine 23 (Angew. Chem. Int. Ed 2018, 57, 4063. ). Xile Hu of the Ecole Polytechnique Fédérale de Lausanne showed that the nitrobenzene 25 could be reduced and acylated in situ with 24, leading to the amide 26 (J. Am. Chem. Soc. 2018, 140, 6789. ). Stephen L. Buchwald of MIT dehydrated the amide 27 to the nitrile 28 (J. Am. Chem. Soc. 2018, 140, 1627. ). Wataru Muramatsu and Hisashi Yamamoto of Chubu University used a niobium catalyst to couple 29 with 30, then reduced the product with high diastereocontrol to 31 (ACS Catal. 2018, 8, 2181. ).
The importance of omega-3 fatty acids in human nutrition has led to interest in the physiological activity of the mammalian metabolites of those acids. En route to one such, resolvin D4 (34), Yuichi Kobayashi of the Tokyo Institute of Technology converted the epoxy silane 32 to the unsaturated nitrile 33 (J. Org. Chem. 2018, 83, 3906. ).