144127-35-5Relevant articles and documents
Samarium diiodide mediated ketyl-aryl coupling reactions - Influence of substituents and trapping experiments
Wefelscheid, Ulrike K.,Berndt, Mathias,Reissig, Hans-Ulrich
experimental part, p. 3635 - 3646 (2009/06/06)
This comprehensive study describes the influence of substituents at the aryl moiety on SmI2-mediated intramolecular ketyl-aryl coupling reactions. Differently substituted γ-aryl ketones were employed as precursors, which were directly prepared
Electroreductive Intramolecular Coupling of Nonconjugated Aromatic Ketones
Kise, Naoki,Suzumoto, Takeshi,Shono, Tatsuya
, p. 1407 - 1413 (2007/10/02)
The electroreduction of nonconjugated aromatic ketones gave intramolecularly coupled products.The best result was obtained using an Sn cathode in i-PrOH containing tetraalkylammonium salt as a supporting electrolyte.This reductive cyclization proceeded with remarkable stereoselectivity, and the cis isomer was obtained exclusively.A variety of new bi- and polycyclic compounds were synthesized.The reaction mechanism was studied, and it was suggested that the anion radical generated by one-electron transfer to a carbonyl group attacks an aromatic ring intramolecularly.The choice of counter cation of the anion radical was critical for the reductive cyclization.Other reductive methods employing metal reducing agents were also studied.Reduction with Na in HMPA-THF gave the same cyclized product, though the yield was lower than that with the electroreduction.
Electrochemical Reduction of Ketones Mediated by (Dimethylpyrrolidinio)mercury. Reductive Cyclization of Unsaturated Ketones and Redox Catalysis Studies
Swartz, James E.,Mahachi, Tendai J.,Kariv-Miller, Essie
, p. 3622 - 3628 (2007/10/02)
The mechanism of dimethylpyrrolidinium (DMP(+1)) mediation of the reductive cyclization of 6-hepten-2-one at a mercury electrode was studied.The initial step of the reduction involves formation of a solid composite, (DMP)Hg5, which then transfers an electron to the ketone, regenerating DMP(1+) and Hgo.The ketyl radical anion cyclizes to form a primary alkyl radical, which can either abstract a hydrogen atom from the solvent, dimethylformamide, or be reduced to the corresponding carbanion.Protonation gives 1,2-dimethylcyclopentanol.Both direct and DMP(1+)-mediated reductions of 7-octen-2-one, 5-phenyl-2-pentanone, and 6-heptyn-2-one were studied.All three compounds give cyclic alcohols when the reduction is mediated by DMP(1+).The former two compounds give the corresponding straight-chain alcohols when reduced directly.The latter gives the same cyclized product upon both direct or DMP(1+)-mediated reduction.Redox catalysis studies show that DMP(1+) is a remarkably effective catalysts for the reduction of ketones.The effectiveness of the catalysis correlates with the expected rates of cyclization of the unsaturated ketones and is consistent with a mechanism involving mediation by solid (DMP)Hg5.Redox catalysis studies of the reduction of cyclohexanones indicate that DMP(1+)-mediated reductions are accelerated by increasing , and the results are discussed in terms of a mechanism leading to pinacol formation.
