Organic Chemistry Portal
Organic Chemistry Highlights

Monday, May 21, 2012
Douglass F. Taber
University of Delaware

Reduction and Oxidation

Craig M. Williams of the University of Queensland and John Tsanaktsidis of CSIRO Victoria decarboxylated (Org. Lett. 2011, 13, 1944. DOI: 10.1021/ol200290m) the acid 1 to the hydrocarbon 2 by coupling the crude acid chloride, formed in CHCl3, with 3 while irradiating with a tungsten bulb. In a related development, David C. Harrowven of the University of Southampton showed (Chem. Commun. 2011, 46, 6335, not illustrated. DOI: 10.1039/C0CC01328E) that tin residues can be removed from a reaction mixture by passage through silica gel containing 10% K2CO3.

Sangho Koo of Myong Ji University selectively removed (Org. Lett. 2011, 13, 2682. DOI: 10.1021/ol200779y) the allylic oxygen of 5, leaving the other protected alcohol. Donald Poirier of Laval University reduced (Synlett 2011, 2025. DOI: 10.1055/s-0030-1261164) the nitrile of 7 to a methyl group. Kiyotomi Kaneda of Osaka University prepared (Chem. Eur. J. 2010, 16, 11818, DOI: 10.1002/chem.201001387; Angew. Chem. Int. Ed. 2011, 50, 2986, DOI: 10.1002/anie.201007679) supported nanoparticles that deoxygenated an epoxide 9 to the alkene 10. Epoxides of cyclic alkenes also worked well.

Shahrokh Saba of Fordham University aminated (Tetrahedron Lett. 2011, 52, 129. DOI: 10.1016/j.tetlet.2010.11.006) the ketone 11 by heating it with an amine 12 in the presence of ammonium formate. Shuangfeng Yin and Li-Biao Han of Hunan University devised (J. Am. Chem. Soc. 2011, 133, 17037. DOI: 10.1021/ja2069246) catalyst systems that reduced the alkyne 14 selectively to either the Z or the E product. Professor Kaneda of Osaka University uncovered (Chem. Lett. 2011, 40, 405. DOI: 10.1246/cl.2011.405) a reliable Pd catalyst for the hydrogenation (not illustrated) of an alkyne to the Z alkene.

David R. Spring of the University of Cambridge established (Synlett 2011, 1917. DOI: 10.1055/s-0030-1260950) biphasic reaction conditions for the conversion of 16 to the azide 18 that were compatible with the base-sensitive Fmoc protecting group. Noritaka Mizuno of the University of Tokyo developed (J. Org. Chem. 2011, 76, 4606. DOI: 10.1021/jo2004956) a Ru catalyst for the transformation of an alkyl azide 19 to the nitrile 20.

Chi-Ming Che of the University of Hong Kong (Synlett 2011, 1174. DOI: 10.1055/s-0030-1260531) and Philip Wai Hong Chan of Nanyang Technological University (J. Org. Chem. 2011, 76, 4894. DOI: 10.1021/jo200284a) independently oxidized an aldehyde 21 to the amide 22. Recognizing (J. Org. Chem. 2011, 76, 2937. DOI: 10.1021/jo2003264) that the primary alcohol 23 would be more reactive than methanol, Yasushi Obora and Yasutaka Ishii of Kansai University effected direct oxidation to the ester 24.

Bo Xu of the University of Louisville oxidized (Tetrahedron Lett. 2011, 52, 1956. DOI: 10.1016/j.tetlet.2011.02.059) the amide 25 to the imide 26. S. Shaun Murphree of Allegheny College oxidized (Org. Lett. 2011, 13, 1447. DOI: 10.1021/ol200135m) the sulfone 27 to the acid 28. Shannon S. Stahl of the University of Wisconsin developed (J. Am. Chem. Soc. 2011, 133, 14566. DOI: 10.1021/ja206575j) a Pd-mediated protocol for the oxidation of the ketone 29 to the enone 30.

The apparently simple conversion of an alkene 31 to the alkyne 32 has been a long-standing problem in organic synthesis. Noriki Kutsumura and Takao Saito of the Tokyo University of Science reported (Synthesis 2011, 2377. DOI: 10.1055/s-0030-1260089) encouraging results using tetrabutylammonium fluoride to effect elimination.

D. F. Taber, Org. Chem. Highlights 2012, May 21.