Monday, September 12, 2016
Douglass F. Taber
University of Delaware
Reactions of Alkenes
Continuing ( 2015, March 30) his studies of selective hydrogenation, Seth B. Herzon of Yale University showed (Chem. Sci. 2015, 6, 6250. ) that the 1,1-disubstituted alkene of 1 could be reduced in the presence of the 1,2-disubstituted alkene. Pd-catalyzed hydrogenation would show the opposite selectivity. In an alternative to Wacker oxidation, Doris Kunz of the Eberhard Karls Universität Tübingen found (Chem. Commun. 2015, 51, 1897. ) that the epoxide 3 could be rearranged to the methyl ketone 4. In related work, Geoffrey W. Coates of Cornell University observed (J. Am. Chem. Soc. 2015, 137, 15049. ) high regioselectivity in the rearrangement of the internal epoxide 5 to the ketone 6.
The hydroboration of alkenes is well known. In a variation, Tomoya Miura and Masahiro Murakami of Kyoto University demonstrated (Angew. Chem. Int. Ed. 2015, 54, 12659. ) that an alkene 7 could be converted in the presence of the reactive alkene norbornene 8 to the alkenyl boronate 9.
Arumugam Sudalai of National Chemical Laboratory developed (Chem. Commun. 2015, 51, 10276. ) conditions for the regioselective oxidation of an alkene 10 to the azido alcohol 11. Yohei Shimizu of the University of Tokyo and Motomu Kanai of the Kanai Life Science Catalysis Project established (Chem. Eur. J. 2015, 21, 15955. ) conditions for the oxidation of an alkene selectively to either regioisomer of the borane ether 13.
Phil S. Baran of Scripps/La Jolla effected (J. Am. Chem. Soc. 2015, 137, 8046. ) the direct addition of a methyl group to the alkene 14, leading to 15. Sunliang Cui of Zhejiang University achieved (Org. Lett. 2015, 17, 4572. ) the direct alkenylation of 14, to give 16. Matthias Beller of the Universität Rostock uncovered (Angew. Chem. Int. Ed. 2015, 54, 10239. ) conditions for preparation of the imide 19 by the carbonylation of the alkene 17 in the presence of the secondary amide 18. Stefan Mecking of the University of Konstanz optimized (ACS Catal. 2015, 5, 4519. ) the preparation of 21 by the isomerizing alkoxycarbonylation of 20.
Bin Xiao and Yao Fu of the University of Science and Technology of China showed (Angew. Chem. Int. Ed. 2015, 54, 12957. ) that depending on the ligand used, the alkylative boration of the alkene 22 with the iodide 23 could be directed selectively toward either regioisomer of the product 24. Markus R. Heinrich of the Friedrich-Alexander-Universität Erlangen-Nürnberg added (Org. Lett. 2015, 17, 6122. ) two equivalents of the diazonium salt 26 to the alkene 25 to give 27. Osamu Tamura of the Tokushima Bunri University observed (J. Org. Chem. 2015, 80, 4797. ) that dipolar cycloaddition of 28 to the alkene 12 delivered the adduct 29 with high diastereocontrol.
Peter A. Wade of Drexel University reported (Tetrahedron Lett. 2015, 56, 6722. ) that the nitro amide derived from the alkene 30 was an excellent Michael donor. Addition to methyl acrylate 31 in the presence of DBU led to the product 32 with remarkable diastereocontrol.
D. F. Taber, Org. Chem. Highlights 2016, September 12.