Organic Chemistry Portal
Organic Chemistry Highlights

Monday, September 19, 2011
Douglass F. Taber
University of Delaware

Functionalization and Homologation of Alkenes

Masahito Ochiai developed (Reduction, Oxidation and Homologation of Alkenes 2008, March 24) the iodosobenzene-mediated cleavage of alkenes to keto aldehydes. Thottumkara K. Vinod of Western Illinois University described (Org. Lett. 2010, 12, 5640. DOI: 10.1021/ol1023807) a modified protocol that delivered the keto acid 2. Chi-Ming Che of the University of Hong Kong established (J. Am. Chem. Soc. 2010, 132, 13229. DOI: 10.1021/ja100967g) a method for the preparative scale Fe-catalyzed cis dihydroxylation of an alkene 3. Ilhyong Ryu of Osaka Prefecture University devised (Synlett 2010, 2014. DOI: 10.1055/s-0030-1258482) a practical procedure for the free radical addition of HBr to an alkene 5. Tetsuo Ohta of Doshisha University showed (Tetrahedron Lett. 2010, 51, 2806. DOI: 10.1016/j.tetlet.2010.03.052) that a Ru catalyst could add an aromatic acid to the internal carbon of a terminal alkene 7.

Noriki Kutsumura and Takao Saito of the Tokyo University of Science found (Org. Lett. 2010, 12, 3316. DOI: 10.1021/ol101110v) conditions for bromination/dehydrobromination to convert 10 to 11. Tsuyoshi Taniguchi of Kanazawa University oxidized (J. Org. Chem. 2010, 75, 8126. DOI: 10.1021/jo101769d) the alkene 12 to the nitro alkene 13.

Professor Taniguchi added (Angew. Chem. Int. Ed. 2010, 49, 10154. DOI: 10.1002/anie.201005574) methyl carbazate to 14 to give the β-hydroxy ester 15. Philippe Renaud of the University of Bern effected (J. Am. Chem. Soc. 2010, 132, 17511. DOI: 10.1021/ja1068036) the free radical homologation of 16 to the azide 18. Daniel P. Becker of Loyola University described (Tetrahedron Lett. 2010, 51, 3514. DOI: 10.1016/j.tetlet.2010.04.105) the elegant diastereoselective Pd-catalyzed bis-methoxycarbonylation of 19 to the diester 20. Matthew S. Sigman of the University of Utah established (J. Am. Chem. Soc. 2010, 132, 13981. DOI: 10.1021/ja1060998) the oxidative Heck arylation of 21 to 23.

F. Dean Toste of the University of California, Berkeley found (Org. Lett. 2010, 12, 4728. DOI: 10.1021/ol102194c) that the intermediate in the gold-catalyzed alkoxylation of 24 could couple to an aryl silane 25 to give 26. Chun-Yu Ho of the Chinese University of Hong Kong used (Angew. Chem. Int. Ed. 2010, 49, 9182. DOI: 10.1002/anie.201001849) a Ni catalyst to add styrene 27 to the alkene 24. Masahiro Miura of Osaka University effected (J. Org. Chem. 2010, 75, 5421. DOI: 10.1021/jo101214y) the oxidative coupling of 29 with styrene 27 to give the linear product 30.

Several years ago (J. Am. Chem. Soc. 1996, 118, 4198. DOI: 10.1021/ja954147f), Jin Kun Cha, now at Wayne State University, reported a modified Kulinkovich protocol for coupling an ester with an alkene to give the cyclopropanol. Timothy W. Funk of Gettysburg College developed (Tetrahedron Lett. 2010, 51, 6726. DOI: 10.1016/j.tetlet.2010.10.067) an Ir catalyst for the specific cleavage of the cyclopropanol, effecting the net homologation of an alkene 31 to the branched ketone 32.

D. F. Taber, Org. Chem. Highlights 2011, September 19.