Synthetic methods Part (II): oxidation and reduction methods

Synthetic methods Part (ii) oxidation and reduction methods

“…Organocatalysts have been employed by Ebner and Pfaltz for hydrogen transfer reactions to the alkene of a wide range of a,b-unsaturated ketones. 133 They have demonstrated that chiral dihydrobenzo [1,4]oxazines act as excellent hydrogen transfer catalysts. The Nakajima group have been using a range of tertiary amines as hydride transfer agents in the presence of Lewis acids in the selective reduction of the alkene in a,b-unsaturated ketones.…”

Metal-Free Dihydroxylation of Alkenes using Cyclobutane Malonoyl Peroxide

“…For over eighty years, the use of OsO 4 has been developed and refined, forming the basis of one of the most powerful transformations in synthetic chemistry: the Sharpless asymmetric dihydroxylation (SAD) . Despite this reaction's widespread popularity, the toxicity of osmium and high levels of inorganic waste are commonly cited limitations, which has prompted the development of a number of alternative metal catalysts, including palladium, iron, ruthenium, manganese, and copper systems . Metal-free methods for syn- dihydroxylation have been reported; however, this area is considerably less established than their metal-based counterparts. − To date, the development of an asymmetric, metal-free method for the syn -dihydroxylation of alkenes remains an elusive and attractive target.…”