Reactions of Alkenes: The Tanino Synthesis of 2-Isocyanoallopupukeanane

Yasunori Toda and Hiroyuki Suga of Shinshu University achieved high regioselectivity in the conversion of the epoxide derived from 1 to the oxazoline 2 (Chem. Commun. 2022, 58, 11819. ). David A. Candito of Merck Process observed the opposite regioselectivity in the conversion of the epoxide derived from 3 to the azido alcohol 4 (Org. Process Res. Dev. 2022, 26, 3034. ). Hao Wang and Fei Wang of Nankai University prepared the amine 7 by coupling the alkene 5 with the alkene 6 (J. Am. Chem. Soc. 2022, 144, 16316. ). Guohua Zhao of Tongji University and Xin-Hao Li of Shanghai Jiao Tong University developed a Ru catalyst for the electrochemical conversion of the alkene 8 to the epoxide 9 (Angew. Chem. Int Ed. 2022, 61, e202207108. ).

Hong-Mei Sun of Soochow University added the benzimidazole 11 to the alkene 10 to give the benzimidazole 12, a protected form of the carboxylic acid (Org. Lett. 2022, 24, 8875. ). Yusuke Kuroda of Kyoto University prepared the amide 15 by coupling the alkene 13, the triazoledione 14, and ethyl magnesium bromide (Org. Lett. 2022, 24, 6224. ). Samir Z. Zard of the Ecole Polytechnique added the xanthate 16 to the alkene 17, leading, after dehydration, to the 2-alkyl cyclohexenone 18 (Org. Lett. 2022, 24, 6973. ). Pan-Pan Zhou and Wei Yu of Lanzhou University assembled the lactam 21 by stitching together the alkene 20 with the N-aminopyridinium salt 19 (Org. Lett. 2022, 24, 6037. ).

Biplab Maji of the Indian Institute of Science Education and Research Kolkata constructed the amide 24 by the three-component coupling of the aryl iodide 23, ethyl iodide, and the alkene 22 (Org. Lett. 2022, 24, 6261. ). In an alternate three-component coupling, Xiaojin Wu of Nanjing Tech University prepared the amide 29 by combining the aryl bromide 26 and the aryl bromide 27 with the alkene 25, in the presence of the promoter 28 (Org. Lett. 2022, 24, 6520. ). Wei Guan of Northeast Normal University and Chao Wang of Tianjin Normal University observed high diastereoselectivity in the coupling of the areneboronic acid 31 with 1-iodobutane and the alkene 30 (Org. Chem. Front. 2022, 9, 6556. ). Mingji Dai of Purdue University also observed high diastereoselectivity in the coupling of the iodoacetal 33 with methyl acrylate 34, leading to the ester 35 (J. Org. Chem. 2022, 87, 8796. ).

2-Isocyanoallopupukeanane (38) was isolated from the nudibranch Phyllidiella putulosa. In the end game of a synthesis of 38, Keiji Tanino of Hokkaido University achieved high diastereoselectivity in the conversion of the alkene 36 to the azide 37 following the Carreira protocol (Org. Lett. 2022, 24, 6407. ).