Complementary Iron(II)‐Catalyzed Oxidative Transformations of Allenes with Different Oxidants. (7th December 2015)

• Record Type: Journal Article
• Authors: Sabbasani, Venkata R.; Lee, Hyunjin; Xia, Yuanzhi; Lee, Daesung
• Is Part Of: Angewandte Chemie. Volume 128:Number 3(2016)
• Page Start: 1163
• Page End: 1167
• Publication Date: 2015-12-07
• Subjects: Allene -- Dichtefunktionalrechnungen -- Eisen -- Oxidationen -- Synthesemethoden; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201510006
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Substituent‐ and oxidant‐dependent transformations of allenes are described. Given the profound influence of the substituent on the reactivity of allenes, the subtle differences in allene structures are manifested in the formation of diverse products when reacted with different electrophiles/oxidants. In general, reactions of nonsilylated allenes involve an allylic cation intermediate by forming a C−O bond, at the sp‐hybridized C2, with either DDQ (2, 3‐dichloro‐5, 6‐dicyano‐ p ‐benzoquinone) or TBHP ( tert ‐butyl hydroperoxide), along with FeCl2 ⋅4 H2 O (10 mol %). In contrast, silylated allenes favor the formation of propargylic cation intermediates by transferring the allenic hydride to the oxidant, thus generating 1, 3‐enynes (E1 product) or propargylic THBP ethers (SN 1 product). The formation of these different putative cationic intermediates from nonsilylated and silylated allenes is strongly supported by DFT calculations.