Olefins are synthetically useful building blocks in modern organic synthesis. Direct functionalization of olefins; represent one of the most explored transformations in synthetic chemistry due to their easy availability and reactivity towards large number of reactants affording diverse range of organic compounds. In recent times, the development of new protocols for the functionalization of olefins is a growing realm. A plethora of olefin functionalization methodologies have been reported in the literature through ionic and free radical mechanisms including single electron transfer (SET) in the last two decades. This review gives an overview of mono-and difunctionalization of unactivated olefins, with an emphasis on the mechanistic details.
Functionalization of Unactivated Olefins via Visible-Light Photocatalysis
Iridium Photo-Catalyzed Reactions
CarbofunctionalizationGlorius and co-workers reported an efficient visible-light mediated three component dicarbofunctionalization of olefins 2 using simple benzylic Katritzky salts 1 as radical precursors (Scheme 1). [8] In this protocol, abundant styrenes, electron-rich heterocycles, and benzylic amines were successfully employed to afford a number of densely functionalized 1,1-diarylalkanes. The optimal reaction conditions for this reaction are [Ir-(dtbbpy)(ppy) 2 ](PF 6 ) (1 mol%) as the photocatalyst in MeCN under irradiation with visible light for 16 h. Under the optimum [a