124876-75-1Relevant academic research and scientific papers
Tetrabutylammonium decatungstate-photosensitized alkylation of electrophilic alkenes: Convenient functionalization of aliphatic C-H bonds
Dondi, Daniele,Fagnoni, Maurizio,Albini, Angelo
, p. 4153 - 4163 (2006)
Tetrabutylammonium decatungstate (TBADT, 2×10-3M) is an effective photocatalyst for the alkylation of electrophilic alkenes (0.1 M, α,β-unsaturated nitriles, esters, ketones) by alkanes, alcohols, and ethers. The products are in most cases obtained in >70% isolated yields, through an experimentally very simple procedure. The kinetics of the radical processes following initial hydrogen abstraction by excited TBADT in deoxygenated MeCN have been studied. In the absence of a trap, back hydrogen transfer from reduced tungstate is the main pathway for alkyl radicals, while α-hydroxyalkyl radicals are oxidized to ketones by ground-state TBADT. With both radical types the reaction ceases at a few percent conversion. However, trapping by electrophilic alkenes is followed by reduction of the radical adduct and regeneration of the catalyst, which allows the alkylation to proceed up to complete alkene conversion with the mentioned good yields of products. With a nucleophilic (α-hydroxyalkyl) radical, alkylation is efficient (Φ = 0.58) and can also be carried out when degassing is omitted, the only difference being a short induction period. With a less reactive (cyclohexyl) radical, the quantum yield is lower (Φ = 0.06) and the reaction is considerably slowed in aerated solutions, but the chemical yield remains good.
Dimeric Metal Complexes as Mediator for Radical C-C Bond-Forming Reactions
Giese, Bernd,Thoma, Gebhard
, p. 1135 - 1142 (2007/10/02)
Irradiation of dicarbonyl(η5-cyclopentadienyl)iron dimer 1 or decacarbonyldimanganese (2) in the presence of alkyl halides leads to C-centered radicals which can be trapped by alkenes and yields saturated and/or unsaturated addition products.Carbon radicals are generated via halogen abstraction by the initially formed metal-centered radicals resulting from homolysis of the metal-metal bond of dimeric mediators 1 and 2.No reaction occurs using octacarbonyl dicobalt (3).
GENERATION AND SYNTHETIC USE OF ALKYL RADICALS WITH 2 AS MEDIATOR
Thoma, Gebhard,Giese, Bernd
, p. 2907 - 2910 (2007/10/02)
Irradiation of dimeric iron complex 1 in the presence of alkyl halides yields alkyl radicals that are useful in organic synthesis.
