Reactions of Alkenes
Alkenes, and in particular terminal alkenes, are readily prepared (e.g. J. Org. Chem. 1997, 62, 9342. DOI: 10.1021/jo9710386), and are unreactive enough that they can be carried through several steps of a synthesis without protection. Reactions that are specific to alkenes are therefore of particular importance. Stephen M. Goldup of the University of Southampton devised (Org. Biomol. Chem. 2016, 14, 5622. DOI: 10.1039/C6OB00692B) what appears to be a general protocol for the anti-Markovnikov addition of HBr to an alkene, as illustrated by the conversion of 1 to 2. Hajime Ito of Hokkaido University established (Chem. Commun. 2016, 52, 5916. DOI: 10.1039/C6CC00782A) a procedure for the Markovnikov hydroboration of 3 to 4. Donald A. Watson of the University of Delaware developed (J. Am. Chem. Soc. 2016, 138, 5539. DOI: 10.1021/jacs.6b02914) the Heck-like borylation of 5 to 6. Michael P. Shaver and Stephen P. Thomas of the University of Edinburgh effected (Chem. Asian J. 2016, 11, 977, DOI: 10.1002/asia.201501098; Chem. Sci. 2016, 7, 3031, DOI: 10.1039/C5SC04471E) the amination of 8 to 9. Sunliang Cui of Zhejiang University also reported (Org. Lett. 2016, 18, 128. DOI: 10.1021/acs.orglett.5b03317) a procedure (not illustrated) for the Markovnikov amination of an alkene.
Keisuke Yoshida and Ken-ichi Takao of Keio University converted (Adv. Synth. Catal. 2016, 358, 1886. DOI: 10.1002/adsc.201600209) the epoxide 10 into the protected chlorohydrin 12. Kilian Muñiz of ICIQ effected (Org. Lett. 2016, 18, 2998, DOI: 10.1021/acs.orglett.6b01368; Chem. Eur. J. 2016, 22, 7367, DOI: 10.1002/chem.201601128) the oxidative bis-amination of 13 to give 14. Arumugam Sudalai of the National Chemical Laboratory converted (Org. Lett. 2016, 18, 500. DOI: 10.1021/acs.orglett.5b03540) the alkene 13 directly to the imido ketone 16. John Hartwig of the University of California, Berkeley, observed (J. Am. Chem. Soc. 2016, 138, 762. DOI: 10.1021/jacs.5b12153) high regioselectivity and diastereoselectivity in the formation of 18 by the Ir-catalyzed borylation of an alkyl silane, itself the product of direct silylation of the alkene 17.
Huanfeng Jiang of the South China University of Technology added (Chem. Commun. 2016, 52, 2628. DOI: 10.1039/C5CC08867D) acetate to the alkene 19 under oxidation conditions, to give the γ-lactone 20. Jin Kun Cha of Wayne State University showed (Tetrahedron Lett. 2016, 56, 3298. DOI: 10.1126/science.aae0427) that the product from Kulinkovich cyclopropanation of the alkene 21 could be selectively protected, then opened with NBS to give the bromo ketone 22. Bill Morandi of the Max-Planck-Institut für Kohlenforschung developed (Science 2016, 351, 832. DOI: 10.1126/science.aae0427) conditions for the reversible hydrocyanation of an alkene, converting 23 to 25 with the donor 24. Hua-Jian Xu of the Hefei University of Technology described (Chem. Commun. 2016, 52, 6793. DOI: 10.1039/C6CC01530A) an alternative protocol for alkene hydrocyanation. Yu Shibata and Ken Tanaka of the Tokyo Institute of Technology effected (Org. Lett. 2016, 18, 2934. DOI: 10.1021/acs.orglett.6b01288) the oxidative arylation of 13 with 26 to give 27.
Professor Cui also added (Org. Lett. 2016, 18, 2722. DOI: 10.1021/acs.orglett.6b01173) the p-quinone methide 29 to the alkene 28, leading to 30. Matthew S. Sigman of the University of Utah established (Org. Lett. 2016, 18, 1792. DOI: 10.1021/acs.orglett.6b00517) the net three-component coupling of the alkene 31, the alkenyl nonaflate 32, and the alkenyl boronic acid 33 to give the alkene 34.